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Awesome

An open API service indexing awesome lists of open source software.

awesome-java

A curated list of awesome frameworks, libraries and software for the Java programming language.
https://github.com/akullpp/awesome-java

Last synced: about 9 hours ago
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  • Resources

  • Projects

    • Security

      • Themis - Multi-platform high-level cryptographic library provides easy-to-use encryption for protecting sensitive data: secure messaging with forward secrecy, secure data storage (AES256GCM); suits for building end-to-end encrypted applications.
      • Apache Shiro - Performs authentication, authorization, cryptography and session management.
      • Bouncy Castle - All-purpose cryptographic library and JCA provider offering a wide range of functions, from basic helpers to PGP/SMIME operations.
      • Keycloak - Integrated SSO and IDM for browser apps and RESTful web services.
      • OACC - Provides permission-based authorization services.
      • Passay - Enforce password policy by validating candidate passwords against a configurable rule set.
      • Topaz - Fine-grained authorization for applications with support for RBAC, ABAC, and ReBAC.
      • DependencyCheck - Detects publicly disclosed vulnerabilities contained within a project's dependencies.
      • Keywhiz - System for distributing and managing secrets.
      • pac4j - Security engine.
      • OpenAM - Access management solution that includes authentication, SSO, authorization, federation, entitlements and web services security.
      • jjwt - JSON web token for Java and Android.
      • Jwks RSA - JSON Web Key Set parser.
      • SecurityBuilder - Fluent Builder API for JCA and JSSE classes and especially X.509 certificates.
      • Tink - Provides a simple and misuse-proof API for common cryptographic tasks.
      • jwt-java - Easily create and parse JSON Web Tokens and create customized JWT validators using a fluent API.
      • Hdiv - Runtime application that repels application security risks included in the OWASP Top 10, including SQL injection, cross-site scripting, cross-site request forgery, data tampering, and brute force attacks.
      • Password4j - User-friendly cryptographic library that supports Argon2, Bcrypt, Scrypt, PBKDF2 and various other cryptographic hash functions.
      • Nbvcxz - Advanced password strength estimation.
      • OTP-Java - One-time password generator library according to RFC 4226 (HOTP) and RFC 6238 (TOTP).
      • Kalium - Binding for the Networking and Cryptography (NaCl) library.
      • Bouncy Castle - All-purpose cryptographic library and JCA provider offering a wide range of functions, from basic helpers to PGP/SMIME operations.
      • Ayza - High-level SSL configuration builder for configuring HTTP clients and servers with SSL/TLS.
      • OACC - Provides permission-based authorization services.
      • Keycloak - Integrated SSO and IDM for browser apps and RESTful web services.
      • Passay - Enforce password policy by validating candidate passwords against a configurable rule set.
      • Topaz - Fine-grained authorization for applications with support for RBAC, ABAC, and ReBAC.

    • Code Analysis

      • Infer - Modern static analysis tool for verifying the correctness of code.
      • jQAssistant - Static code analysis with Neo4J-based query language. (GPL-3.0-only)
      • PMD - Source code analysis for finding bad coding practices.
      • p3c - Provides Alibaba's coding guidelines for PMD, IDEA and Eclipse.
      • Checkstyle - Static analysis of coding conventions and standards. (LGPL-2.1-or-later)
      • Error Prone - Catches common programming mistakes as compile-time errors.
      • NullAway - Eliminates NullPointerExceptions with low build-time overhead.
      • SonarJava - Static analyzer for SonarQube & SonarLint. (LGPL-3.0-only)
      • Spoon - Library for analyzing and transforming Java source code.
      • Spotbugs - Static analysis of bytecode to find potential bugs. (LGPL-2.1-only)
      • Error Prone Support - Error Prone extensions: extra bug checkers and a large battery of Refaster templates.
      • RefactorFirst - Identifies and prioritizes God Classes and Highly Coupled classes.
      • jQAssistant - Static code analysis with Neo4J-based query language. (GPL-3.0-only)

    • JSON

      • Gson - Serializes objects to JSON and vice versa. Good performance with on-the-fly usage.
      • Jackson - Similar to GSON, but offers performance gains if you need to instantiate the library more often.
      • Moshi - Modern JSON library, less opinionated and uses built-in types like List and Map.
      • Avaje Jsonb - Reflection-free Json binding via source code generation with Jackson-like annotations.
      • Genson - Powerful and easy-to-use Java-to-JSON conversion library.
      • Genson - Powerful and easy-to-use Java-to-JSON conversion library.
      • fastjson - Very fast processor with no additional dependencies and full data binding.
      • JsonPath - Extract data from JSON using XPATH-like syntax.
      • DSL-JSON - JSON library with advanced compile time databinding.
      • HikariJSON - High-performance JSON parser, 2x faster than Jackson.
      • jackson-modules-java8 - Set of Jackson modules for Java 8 datatypes and features.
      • Jackson-datatype-money - Open-source Jackson module to support JSON serialization and deserialization of JavaMoney data types.
      • JSON-io - Convert Java to JSON. Convert JSON to Java. Pretty print JSON. Java JSON serializer.
      • LoganSquare - JSON parsing and serializing library based on Jackson's streaming API. Outperforms GSON & Jackson's library.
      • Yasson - Binding layer between classes and JSON documents similar to JAXB.
      • Jolt - JSON to JSON transformation tool.
      • JsonSurfer - Streaming JsonPath processor dedicated to processing big and complicated JSON data.

    • Database

      • Realm - Mobile database to run directly inside phones, tablets or wearables.
      • requery - Modern, lightweight but powerful object mapping and SQL generator. Easily map to or create databases, or perform queries and updates from any Java-using platform.
      • MapDB - Embedded database engine that provides concurrent collections backed on disk or in off-heap memory.
      • Apache Calcite - Dynamic data management framework. It contains many of the pieces that comprise a typical database management system.
      • Apache Drill - Distributed, schema on-the-fly, ANSI SQL query engine for Big Data exploration.
      • Apache Phoenix - High-performance relational database layer over HBase for low-latency applications.
      • Debezium - Low latency data streaming platform for change data capture.
      • druid - High-performance, column-oriented, distributed data store.
      • H2 - Small SQL database notable for its in-memory functionality.
      • HSQLDB - HyperSQL 100% Java database.
      • JDBI - Convenient abstraction of JDBC.
      • Lettuce - Lettuce is a scalable Redis client for building non-blocking Reactive applications.
      • Querydsl - Typesafe unified queries.
      • Trino - Distributed SQL query engine for big data.
      • Vibur DBCP - JDBC connection pool library with advanced performance monitoring capabilities.
      • Querydsl - Typesafe unified queries.
      • QuestDB - High-performance SQL database for time series. Supports InfluxDB line protocol, PostgreSQL wire protocol, and REST.
      • Apache ShardingSphere - Distributed SQL transaction & query engine that allows for data sharding, scaling, encryption, and more on any database.
      • HikariCP - High-performance JDBC connection pool.
      • ArangoDB - ArangoDB Java driver.
      • Chronicle Map - Efficient, in-memory (opt. persisted to disk), off-heap key-value store.
      • eXist - NoSQL document database and application platform. (LGPL-2.1-only)
      • FlexyPool - Brings metrics and failover strategies to the most common connection pooling solutions.
      • Jest - Client for the Elasticsearch REST API.
      • jetcd - Client library for etcd.
      • Jinq - Typesafe database queries via symbolic execution of Java 8 Lambdas (on top of JPA or jOOQ).
      • Leaf - Distributed ID generate service.
      • MariaDB4j - Launcher for MariaDB that requires no installation or external dependencies.
      • Redisson - Allows for distributed and scalable data structures on top of a Redis server.
      • Speedment - Database access library that utilizes Java 8's Stream API for querying.
      • Modality - Lightweight ORM with database reverse engineering features.
      • QueryStream - Build JPA Criteria queries using a Stream-like API.
      • Xodus - Highly concurrent transactional schema-less and ACID-compliant embedded database.
      • OpenDJ - LDAPv3 compliant directory service, developed for the Java platform, providing a high performance, highly available, and secure store for the identities.
      • Spring Data JPA MongoDB Expressions - Allows you to use MongoDB query language to query your relational database.
      • CosId - Universal, flexible, high-performance distributed ID generator.
      • Trino - Distributed SQL query engine for big data.
      • Spring Data Dynamic Query - Unified dynamic query interface for Spring Data JPA, MongoDB, and Elasticsearch, enabling advanced JOIN(s), OR logic, scoped conditions, powerful projections and advanced features with zero boilerplate.
      • Apache Calcite - Dynamic data management framework. It contains many of the pieces that comprise a typical database management system.
      • Apache Drill - Distributed, schema on-the-fly, ANSI SQL query engine for Big Data exploration.
      • Jedis - Small client for interaction with Redis, with methods for commands.
      • Vibur DBCP - JDBC connection pool library with advanced performance monitoring capabilities.

    • HTTP Clients

      • Retrofit - Typesafe REST client.
      • Apache HttpComponents - Toolset of low-level Java components focused on HTTP and associated protocols.
      • Avaje Http Client - Wrapper on JDK 11's HttpClient that adds Feign-like interface among other enhancements.
      • Ribbon - Client-side IPC library that is battle-tested in the cloud.
      • Async Http Client - Asynchronous HTTP and WebSocket client library.
      • unirest-java - Simplified, lightweight HTTP client library.
      • Feign - HTTP client binder inspired by Retrofit, JAXRS-2.0, and WebSocket.
      • Riptide - Client-side response routing for Spring's RestTemplate.
      • Google HTTP Client - Pluggable HTTP transport abstraction with support for java.net.HttpURLConnection, Apache HTTP Client, Android, Google App Engine, XML, Gson, Jackson and Protobuf.
      • methanol - HTTP client extensions library.

    • Data Structures

      • Tape - Lightning-fast, transactional, file-based FIFO.
      • Apache Avro - Data interchange format with dynamic typing, untagged data, and absence of manually assigned IDs.
      • Apache Orc - Fast and efficient columnar storage format for Hadoop-based workloads.
      • Protobuf - Google's data interchange format.
      • Wire - Clean, lightweight protocol buffers.
      • Big Queue - Fast and persistent queue based on memory-mapped files.
      • HyperMinHash-java - Probabilistic data structure for computing union, intersection, and set cardinality in loglog space.
      • Persistent Collection - Persistent and immutable analogue of the Java Collections Framework.
      • RoaringBitmap - Fast and efficient compressed bitmap.
      • SBE - Simple Binary Encoding, one of the fastest message formats around.
      • Apache Orc - Fast and efficient columnar storage format for Hadoop-based workloads.

    • Utility

      • Guava - Collections, caching, primitives support, concurrency libraries, common annotations, string processing, I/O, and more.
      • JADE - Framework and environment for building and debugging multi-agent systems. (LGPL-2.0-only)
      • JGit - Lightweight, pure Java library implementing the Git version control system.
      • Protégé - Provides an ontology editor and a framework to build knowledge-based systems.
      • JavaVerbalExpressions - Library that helps with constructing difficult regular expressions.
      • Arthas - Allows to troubleshoot production issues for applications without modifying code or restarting servers.
      • Gephi - Cross-platform for visualizing and manipulating large graph networks. (GPL-3.0-only)
      • Embulk - Bulk data loader that helps data transfer between various databases, storages, file formats, and cloud services.
      • cactoos - Collection of object-oriented primitives.
      • Dex - Java/JavaFX tool capable of powerful ETL and data visualization.
      • minio-java - Provides simple APIs to access any Amazon S3-compatible object storage server.
      • fswatch - Micro library to watch for directory file system changes, simplifying java.nio.file.WatchService.
      • Underscore-java - Port of Underscore.js functions.
      • Chocotea - Generates postman collection, environment and integration tests from java code.
      • dregex - Regular expression engine that uses deterministic finite automata. It supports some Perl-style features and yet retains linear matching time, and also offers set operations.
      • Javadoc Publisher - Generate Javadoc from your maven/gradle project and deploy it automatically on GitHub Page.
      • CRaSH - Provides a shell into a JVM that's running CRaSH. Used by Spring Boot and others. (LGPL-2.1-or-later)
      • JKScope - Java scope functions inspired by Kotlin.
      • Semver4j - Lightweight library that helps you handling semantic versioning with different modes.
      • Java Diff Utils - Utilities for text or data comparison and patching.
      • bucket4j - Rate limiting library based on token-bucket algorithm.
      • Protégé - Provides an ontology editor and a framework to build knowledge-based systems.

    • Imagery

      • ZXing - Multi-format 1D/2D barcode image processing library.
      • Imgscalr - Simple, efficient and hardware-accelerated image-scaling library implemented in pure Java 2D.
      • Tess4J - JNA wrapper for Tesseract OCR API.
      • Thumbnailator - High-quality thumbnail generation library.
      • TwelveMonkeys - Collection of plugins that extend the number of supported image file formats.
      • image-comparison - Library that compares 2 images with the same sizes and shows the differences visually by drawing rectangles. Some parts of the image can be excluded from the comparison.
      • vips-ffm - Comprehensive bindings for libvips, using Java's "Foreign Function & Memory" API.
      • Barcode-Lib4J - Generates QR Code, DataMatrix, and other 1D/2D barcodes as vector (PDF, EPS, SVG) and raster (PNG, BMP, JPG) images with DPI awareness, high precision, and CMYK color model support.
      • scrimage - Immutable, functional, and performant JVM library for manipulation of images.

    • Reactive libraries

      • RxJava - Allows for composing asynchronous and event-based programs using observable sequences.
      • Akka - Toolkit and runtime for building concurrent, distributed, fault-tolerant and event-driven applications.
      • Reactive Streams - Provides a standard for asynchronous stream processing with non-blocking backpressure.
      • Reactor - A framework for building non-blocking applications on the JVM, providing support for reactive programming.
      • Akka - Toolkit and runtime for building concurrent, distributed, fault-tolerant and event-driven applications.

    • IDE

      • IntelliJ IDEA ![c - Supports many JVM languages and provides good options for Android development. The commercial edition targets the enterprise sector.
      • jGRASP - Created to provide software visualizations that work in conjunction with the debugger such as Control Structure Diagrams, UML class diagrams and Object Viewer.
      • SnapCode - Modern IDE for Java running in the browser, focused on education.
      • Visual Studio Code - Provides Java support for lightweight projects with a simple, modern workflow by using extensions from the internal marketplace.
      • Eclipse - Established open-source project with support for lots of plugins and languages.
      • jGRASP - Created to provide software visualizations that work in conjunction with the debugger such as Control Structure Diagrams, UML class diagrams and Object Viewer.

    • Performance analysis

      • JMH - Harness for building, running, and analysing nano/micro/milli/macro benchmarks written in Java and other languages targeting the JVM. (GPL-2.0 only WITH Classpath-exception-2.0)
      • fastThread ![c - Analyze and visualize thread dumps with a free cloud-based upload interface.
      • JMH - Harness for building, running, and analysing nano/micro/milli/macro benchmarks written in Java and other languages targeting the JVM. (GPL-2.0 only WITH Classpath-exception-2.0)
      • JITWatch - Analyze the JIT compiler optimisations made by the HotSpot JVM.
      • jHiccup - Logs and records platform JVM stalls.
      • honest-profiler - Low-overhead, bias-free sampling profiler.
      • LatencyUtils - Utilities for latency measurement and reporting.
      • fastThread ![c - Analyze and visualize thread dumps with a free cloud-based upload interface.
      • GCeasy ![c - Tool to analyze and visualize GC logs. It provides a free cloud-based upload interface.

    • JVM and JDK

      • ParparVM - VM with non-blocking, concurrent GC for iOS. (GPL-2.0-only WITH Classpath-exception-2.0)
      • Adopt Open JDK - Community-driven OpenJDK builds, including both HotSpot and OpenJ9.
      • Corretto - No-cost, multiplatform, production-ready distribution of OpenJDK by Amazon. (GPL-2.0-only WITH Classpath-exception-2.0)
      • Liberica JDK - Built from OpenJDK, thoroughly tested and passed the JCK. (GPL-2.0-only WITH Classpath-exception-2.0)
      • Open JDK - Open JDK community home. (GPL-2.0-only WITH Classpath-exception-2.0)
      • RedHat Open JDK - RedHat's OpenJDK distribution. (GPL-2.0-only WITH Classpath-exception-2.0)
      • Zulu - OpenJDK builds for Windows, Linux, and macOS. (GPL-2.0-only WITH Classpath-exception-2.0)
      • Open JDK - Open JDK community home. (GPL-2.0-only WITH Classpath-exception-2.0)
      • Which JDK - Overview of common JVMs with pros and cons.
      • Graal - Polyglot embeddable JVM. (GPL-2.0-only WITH Classpath-exception-2.0)
      • SAP Machine - SAP's no-cost, rigorously tested and JCK-verified OpenJDK friendly fork. (GPL-2.0-only WITH Classpath-exception-2.0)
      • Microsoft JDK - Microsoft Build of OpenJDK, Free, Open Source, Freshly Brewed!
      • OpenJ9 - High performance, enterprise-calibre, flexibly licensed, openly-governed cross-platform JVM extending and augmenting the runtime technology components from the Eclipse OMR and OpenJDK project.
      • Dragonwell8 - Downstream version of OpenJDK optimized for online e-commerce, financial, logistics applications.

    • PaaS

    • Distribution

      • Cloudsmith ![c - Fully managed package management SaaS with support for Maven/Gradle/SBT with a free tier.
      • Boxfuse ![c - Deployment of JVM applications to AWS using the principles of immutable infrastructure.
      • Central Repository - Largest binary component repository available as a free service to the open-source community. Default used by Apache Maven, and available in all other build tools.
      • jDeploy - Deploy desktop apps as native Mac, Windows or Linux bundles.
      • Nexus ![c - Binary management with proxy and caching capabilities.
      • IzPack - Setup authoring tool for cross-platform deployments.
      • Capsule - Simple and powerful packaging and deployment. A fat JAR on steroids, or a "Docker for Java" that supports JVM-optimized containers.
      • packr - Packs JARs, assets and the JVM for native distribution on Windows, Linux and macOS.
      • really-executable-jars-maven-plugin - Maven plugin for making self-executing JARs.
      • Artipie - Binary artifact management toolkit which hosts them on the file system or S3.
      • Getdown - System for deploying Java applications to end-user computers and keeping them up to date. Developed as an alternative to Java Web Start.
      • jlink.online - Builds optimized runtimes over HTTP.
      • JavaPackager - Maven and Gradle plugin which provides an easy way to package Java applications in native Windows, macOS or GNU/Linux executables, and generate installers for them.
      • Boxfuse ![c - Deployment of JVM applications to AWS using the principles of immutable infrastructure.

    • Bytecode Manipulation

      • ASM - All-purpose, low-level bytecode manipulation and analysis.
      • Byte Buddy - Further simplifies bytecode generation with a fluent API.
      • Recaf - JVM reverse engineering toolkit, essentially an IDE for Java bytecode.
      • bytecode-viewer - Java 8 Jar & Android APK reverse engineering suite. (GPL-3.0-only)
      • cglib - Bytecode generation library.
      • Javassist - Tries to simplify bytecode editing.
      • Mixin - Manipulate bytecode at runtime using real Java code.
      • Perses - Dynamically injects failure/latency at the bytecode level according to principles of chaos engineering.
      • Maker - Provides low level bytecode generation.
      • ASM - All-purpose, low-level bytecode manipulation and analysis.
      • Perses - Dynamically injects failure/latency at the bytecode level according to principles of chaos engineering.
      • Byte Buddy - Further simplifies bytecode generation with a fluent API.
      • Byteman - Manipulate bytecode at runtime via DSL (rules); mainly for testing/troubleshooting. (LGPL-2.1-or-later)

    • Caching

      • cache2k - In-memory high performance caching library.
      • Ehcache - Distributed general-purpose cache.
      • Infinispan - Highly concurrent key/value datastore used for caching.
      • Caffeine - High-performance, near-optimal caching library.
      • cache2k - In-memory high performance caching library.
      • Infinispan - Highly concurrent key/value datastore used for caching.

    • CLI

      • JCommander - Command-line argument-parsing framework with custom types and validation via implementing interfaces.
      • picocli - ANSI colors and styles in usage help with annotation-based POSIX/GNU/any syntax, subcommands, strong typing for both options and positional args.
      • Jansi - ANSI escape codes to format console output.
      • JLine - Includes features from modern shells like completion or history.
      • Text-IO - Aids the creation of full console-based applications.
      • Lanterna - Easy console text-GUI library, similar to curses. (LGPL-3.0-only)
      • Airline - Annotation-based framework for parsing Git-like command-line arguments.
      • jbock - Reflectionless command line parser.
      • Jexer - Advanced console (and Swing) text user interface (TUI) library, with mouse-draggable windows, built-in terminal window manager, and sixel image support. Looks like [Turbo Vision](https://en.wikipedia.org/wiki/Turbo_Vision).

    • Cluster Management

      • Apache Aurora - Mesos framework for long-running services and cron jobs.
      • Singularity - Mesos framework that makes deployment and operations easy. It supports web services, background workers, scheduled jobs, and one-off tasks.

    • Code Coverage

      • Clover - Relies on source-code instrumentation instead of bytecode instrumentation.
      • JaCoCo - Framework that enables collection of code coverage metrics, using both offline and runtime bytecode instrumentation.
      • Cobertura - Relies on offline (or static) bytecode instrumentation and class loading to collect code coverage metrics. (GPL-2.0-only)

    • Code Generators

      • Avaje Http Server - Generates Lightweight JAX-RS style http servers using Javalin or Helidon (Nima) SE.
      • Bootify ![c - Browser-based Spring Boot app generation with JPA model and REST API.
      • Immutables - Annotation processors to generate simple, safe and consistent value objects.
      • Joda-Beans - Small framework that adds queryable properties to Java, enhancing JavaBeans.
      • JPA Buddy ![c - Plugin for IntelliJ IDEA. Provides visual tools for generating JPA entities, Spring Data JPA repositories, Liquibase changelogs and SQL scripts. Offers automatic Liquibase/Flyway script generation by comparing model to DB, and reverse engineering JPA entities from DB tables.
      • Telosys - Simple and light code generator available as an Eclipse Plugin and also as a CLI.
      • JHipster - Yeoman source code generator for Spring Boot and AngularJS.
      • ADT4J - JSR-269 code generator for algebraic data types.
      • Auto - Generates factory, service, and value classes.
      • FreeBuilder - Automatically generates the Builder pattern.
      • JavaPoet - API to generate source files.
      • Geci - Discovers files that need generated code, updates automatically and writes to the source with a convenient API.
      • Record-Builder - Companion builder class, withers and templates for Java records.
      • EasyEntityToDTO - Annotation processor for automatic DTO and Mapper generation with zero boilerplate.
      • JSpecify Package-Info Generator - Maven plugin that automatically generates package-info.java files with JSpecify annotations (@NullMarked and @NullUnmarked), helping you manage nullness boundaries in your Java projects without manual boilerplate.
      • Bootify ![c - Browser-based Spring Boot app generation with JPA model and REST API.
      • Immutables - Annotation processors to generate simple, safe and consistent value objects.
      • JPA Buddy ![c - Plugin for IntelliJ IDEA. Provides visual tools for generating JPA entities, Spring Data JPA repositories, Liquibase changelogs and SQL scripts. Offers automatic Liquibase/Flyway script generation by comparing model to DB, and reverse engineering JPA entities from DB tables.

    • Compiler-compiler

      • JFlex - Lexical analyzer generator.
      • JavaCC - Parser generator that generates top-down parsers. Allows lexical state switching and permits extended BNF specifications.
      • ANTLR - Complex full-featured framework for top-down parsing.
      • JFlex - Lexical analyzer generator.

    • Computer Vision

      • BoofCV - Library for image processing, camera calibration, tracking, SFM, MVS, 3D vision, QR Code and much more.
      • ImageJ - Medical image processing application with an API.
      • JavaCV - Java interface to OpenCV, FFmpeg, and much more.

    • Configuration

      • avaje config - Loads yaml and properties files, supports dynamic configuration, plugins, file-watching and config event listeners.
      • Curator Framework - High-level API for Apache ZooKeeper.
      • ini4j - Provides an API for handling Windows' INI files.
      • microconfig - Configuration system designed for microservices which helps to separate configuration from code. The configuration for different services can have common and specific parts and can be dynamically distributed.
      • Configurate - Configuration library with support for various configuration formats and transformations.
      • KAConf - Annotation-based configuration system for Java and Kotlin.
      • config - Configuration library supporting Java properties, JSON or its human optimized superset HOCON.
      • centraldogma - Highly-available version-controlled service configuration repository based on Git, ZooKeeper and HTTP/2.
      • dotenv - Twelve-factor configuration library which uses environment-specific files.
      • Externalized Properties - Lightweight yet powerful configuration library which supports resolution of properties from external sources and an extensible post-processing/conversion mechanism.
      • Gestalt - Gestalt offers a comprehensive solution to the challenges of configuration management. It allows you to source configuration data from multiple inputs, merge them intelligently, and present them in a structured, type-safe manner.
      • owner - Reduces boilerplate of properties.

    • Constraint Satisfaction Problem Solver

      • Choco - Off-the-shelf constraint satisfaction problem solver that uses constraint programming techniques.
      • OptaPlanner - Business planning and resource scheduling optimization solver.
      • Timefold - Flexible solver with Spring/Quarkus support and quickstarts for the Vehicle Routing Problem, Maintenance Scheduling, Employee Shift Scheduling and much more.
      • JaCoP - Includes an interface for the FlatZinc language, enabling it to execute MiniZinc models. (AGPL-3.0)
      • Choco - Off-the-shelf constraint satisfaction problem solver that uses constraint programming techniques.
      • OptaPlanner - Business planning and resource scheduling optimization solver.

    • CSV

      • opencsv - Simple CSV parser.
      • FastCSV - Performance-optimized, dependency-free and RFC 4180 compliant.
      • jackson-dataformat-csv - Jackson extension for reading and writing CSV.
      • Super CSV - Powerful CSV parser with support for Dozer, Joda-Time and Java 8.
      • uniVocity-parsers - One of the fastest and most feature-complete parsers. Also comes with parsers for TSV and fixed-width records.
      • opencsv - Simple CSV parser.

    • Dependency Injection

      • Inversion of Control
      • Apache DeltaSpike - CDI extension framework.
      • Avaje Inject - Microservice-focused compile-time injection framework without reflection.
      • Dagger - Compile-time injection framework without reflection.
      • Guice - Lightweight and opinionated framework that completes Dagger.
      • Feather - Ultra-lightweight, JSR-330-compliant dependency injection library.
      • Governator - Extensions and utilities that enhance Google Guice.
      • HK2 - Lightweight and dynamic dependency injection framework.
      • JayWire - Lightweight dependency injection framework. (LGPL-3.0-only)
      • HK2 - Lightweight and dynamic dependency injection framework.

    • Development

      • AspectJ - Seamless aspect-oriented programming extension.
      • DCEVM - JVM modification that allows unlimited redefinition of loaded classes at runtime. (GPL-2.0-only)
      • NoException - Allows checked exceptions in functional interfaces and converts exceptions to Optional return.
      • Faux Pas - Library that simplifies error handling by circumventing the issue that none of the functional interfaces in the Java Runtime is allowed by default to throw checked exceptions.
      • HotswapAgent - Unlimited runtime class and resource redefinition. (GPL-2.0-only)
      • JavaParser - Parse, modify and generate Java code.
      • JavaSymbolSolver - Symbol solver.
      • Manifold - Re-energizes Java with powerful features like type-safe metaprogramming, structural typing and extension methods.
      • SneakyThrow - Ignores checked exceptions without bytecode manipulation. Can also be used inside Java 8 stream operations.
      • Tail - Enable infinite recursion using tail call optimization.
      • NoException - Allows checked exceptions in functional interfaces and converts exceptions to Optional return.
      • AspectJ - Seamless aspect-oriented programming extension.

    • Distributed Applications

      • Apache Geode - In-memory data management system that provides reliable asynchronous event notifications and guaranteed message delivery.
      • Apache Storm - Realtime computation system.
      • Atomix - Fault-tolerant distributed coordination framework.
      • Axon - Framework for creating CQRS applications.
      • JGroups - Toolkit for reliable messaging and cluster creation.
      • Quasar - Lightweight threads and actors for the JVM.
      • Zuul - Gateway service that provides dynamic routing, monitoring, resiliency, security, and more.
      • Hazelcast - Highly scalable in-memory datagrid with a free open-source version.
      • resilience4j - Functional fault tolerance library.
      • Dropwizard Circuit Breaker - Circuit breaker design pattern for Dropwizard. (GPL-2.0-only)
      • ScaleCube Services - Embeddable Cluster-Membership library based on SWIM and gossip protocol.
      • Failsafe - Simple failure handling with retries and circuit breakers.
      • Atomix - Fault-tolerant distributed coordination framework.
      • JGroups - Toolkit for reliable messaging and cluster creation.
      • OpenIG - High-performance reverse proxy server with specialized session management and credential replay functionality.
      • Apache Geode - In-memory data management system that provides reliable asynchronous event notifications and guaranteed message delivery.
      • Axon - Framework for creating CQRS applications.

    • Distributed Transactions

      • Atomikos - Provides transactions for REST, SOA and microservices with support for JTA and XA.
      • Narayana - Provides support for traditional ACID and compensation transactions, also complies with JTA, JTS and other standards. (LGPL-2.1-only)
      • Seata - Delivers high performance and easy to use distributed transaction services under a microservices architecture.
      • Atomikos - Provides transactions for REST, SOA and microservices with support for JTA and XA.
      • Narayana - Provides support for traditional ACID and compensation transactions, also complies with JTA, JTS and other standards. (LGPL-2.1-only)

    • Document Processing

      • Apache POI - Supports OOXML (XLSX, DOCX, PPTX) as well as OLE2 (XLS, DOC or PPT).
      • documents4j - API for document format conversion using third-party converters such as MS Word.
      • docx4j - Create and manipulate Microsoft Open XML files.
      • zerocell - Annotation-based API for reading data from Excel sheets into POJOs with focus on reduced overhead.
      • fastexcel - High performance library to read and write large Excel (XLSX) worksheets.
      • Apache POI - Supports OOXML (XLSX, DOCX, PPTX) as well as OLE2 (XLS, DOC or PPT).

    • Formal Verification

      • Daikon - Detects likely program invariants and generates JML specs based on those invariants.
      • JMLOK 2.0 - Detects inconsistencies between code and JML specification through feedback-directed random tests generation, and suggests a likely cause for each nonconformance detected. (GPL-3.0-only)
      • KeY - Formal software development tool that aims to integrate design, implementation, formal specification, and formal verification of object-oriented software as seamlessly as possible. Uses JML for specification and symbolic execution for verification. (GPL-2.0-or-later)
      • OpenJML - Translates JML specifications into SMT-LIB format and passes the proof problems implied by the program to backend solvers. (GPL-2.0-only)
      • CATG - Concolic unit testing engine. Automatically generates unit tests using formal methods.
      • Java Path Finder (JPF) - JVM formal verification tool containing a model checker and more. Created by NASA.
      • Checker Framework - Pluggable type systems. Includes nullness types, physical units, immutability types and more. (GPL-2.0-only WITH Classpath-exception-2.0)
      • OpenJML - Translates JML specifications into SMT-LIB format and passes the proof problems implied by the program to backend solvers. (GPL-2.0-only)
      • KeY - Formal software development tool that aims to integrate design, implementation, formal specification, and formal verification of object-oriented software as seamlessly as possible. Uses JML for specification and symbolic execution for verification. (GPL-2.0-or-later)

    • Functional Programming

      • Functional Java - Implements numerous basic and advanced programming abstractions that assist composition-oriented development.
      • StreamEx - Enhances Java 8 Streams.
      • protonpack - Collection of stream utilities.
      • Cyclops - Monad and stream utilities, comprehensions, pattern matching, functional extensions for all JDK collections, future streams, trampolines and much more.
      • derive4j - Java 8 annotation processor and framework for deriving algebraic data types constructors, pattern-matching and morphisms. (GPL-3.0-only)
      • Fugue - Functional extensions to Guava.
      • jOOλ - Extension to Java 8 that aims to fix gaps in lambda by providing numerous missing types and a rich set of sequential Stream API additions.
      • Packrat - Gatherers library for Java Stream API. Gatherers can enhance streams with custom intermediate operations.

    • Game Development

      • JBox2D - Port of the renowned C++ 2D physics engine.
      • jMonkeyEngine - Game engine for modern 3D development.
      • Litiengine - AWT-based, lightweight 2D game engine.
      • LWJGL - Robust framework that abstracts libraries like OpenGL/CL/AL.
      • Mini2Dx - Beginner-friendly, master-ready framework for rapidly prototyping and building 2D games.
      • FXGL - JavaFX Game Development Framework.
      • vulkan4j - Vulkan, OpenGL ES2 and GLFW Memory Allocator bindings.
      • JBox2D - Port of the renowned C++ 2D physics engine.
      • Void2D - High-level 2D game engine with built-in physics based on Swing.

    • Geospatial

      • Apache SIS - Library for developing geospatial applications.
      • GeoTools - Library that provides tools for geospatial data. (LGPL-2.1-only)
      • H2GIS - Spatial extension of the H2 database. (LGPL-3.0-only)
      • GraphHopper - Road-routing engine. Used as a Java library or standalone web service.
      • Geo - GeoHash utilities in Java.
      • Jgeohash - Library for using the GeoHash algorithm.
      • Mapsforge - Map rendering based on OpenStreetMap data. (LGPL-3.0-only)
      • Spatial4j - General-purpose spatial/geospatial library.
      • ArcGIS Maps SDK for Java ![c - JavaFX library for adding mapping and GIS functionality to desktop apps.
      • Apache SIS - Library for developing geospatial applications.
      • ArcGIS Maps SDK for Java ![c - JavaFX library for adding mapping and GIS functionality to desktop apps.
      • GeoTools - Library that provides tools for geospatial data. (LGPL-2.1-only)

    • GUI

      • JavaFX - Successor of Swing.
      • Scene Builder - Visual layout tool for JavaFX applications.
      • SWT - Graphical widget toolkit.
      • JavaFX - Successor of Swing.
      • SnapKit - Modern Java UI library for both desktop and web.
      • Sierra - Lightwieght declarative DSL for rapid development of Swing applications.

    • High Performance

      • HPPC - Primitive collections.
      • Disruptor - Inter-thread messaging library.
      • JCTools - Concurrency tools currently missing from the JDK.
      • Koloboke - Carefully designed extension of the Java Collections Framework with primitive specializations and more.
      • Eclipse Collections - Collections framework inspired by Smalltalk.
      • Agrona - Data structures and utility methods that are common in high-performance applications.

    • Introspection

      • Mirror - Mirror was created to bring light to a simple problem, usually named ReflectionUtil, which is on almost all projects that rely on reflection to do advanced tasks.
      • Objenesis - Allows dynamic instantiation without default constructor, e.g. constructors which have required arguments, side effects or throw exceptions.
      • jOOR - jOOR stands for jOOR Object Oriented Reflection. It is a simple wrapper for the java.lang.reflect package.
      • ClassGraph - ClassGraph (formerly FastClasspathScanner) is an uber-fast, ultra-lightweight, parallelized classpath scanner and module scanner for Java, Scala, Kotlin and other JVM languages.
      • ReflectASM - ReflectASM is a very small Java library that provides high performance reflection by using code generation.
      • Reflections - Reflections scans your classpath, indexes the metadata, allows you to query it on runtime and may save and collect that information for many modules within your project.
      • Mirror - Mirror was created to bring light to a simple problem, usually named ReflectionUtil, which is on almost all projects that rely on reflection to do advanced tasks.

    • Logging

      • Apache Log4j 2 - Complete rewrite with a powerful plugin and configuration architecture.
      • Graylog - Open-source aggregator suited for extended role and permission management. (GPL-3.0-only)
      • Kibana - Analyzes and visualizes log files. Some features require payment.
      • Logback - Robust logging library with interesting configuration options via Groovy.
      • Logstash - Tool for managing log files.
      • SLF4J - Abstraction layer/simple logging facade.
      • Logbook - Extensible, open-source library for HTTP request and response logging.
      • p6spy - Enables logging for all JDBC transactions without changes to the code.
      • OpenTracing Toolbox - Collection of libraries that build on top of OpenTracing and provide extensions and plugins to existing instrumentations.
      • Echopraxia - API designed around structured logging, rich context, and conditional logging. There are Logback and Log4J2 implementations, but Echopraxia's API is completely dependency-free, meaning it can be implemented with any logging API.
      • Apache Log4j 2 - Complete rewrite with a powerful plugin and configuration architecture.
      • Flogger - Flogger is a fluent logging API for Java. It supports a wide variety of features, and has many benefits over existing logging APIs.
      • Logback - Robust logging library with interesting configuration options via Groovy.
      • SLF4J - Abstraction layer/simple logging facade.
      • Graylog - Open-source aggregator suited for extended role and permission management. (GPL-3.0-only)

    • Machine Learning

      • Apache Mahout - Scalable algorithms focused on collaborative filtering, clustering and classification.
      • DatumBox - Provides several algorithms and pre-trained models for natural language processing.
      • DJL - High-level and engine-agnostic framework for deep learning.
      • oj! Algorithms - High-performance mathematics, linear algebra and optimisation needed for data science, machine learning and scientific computing.
      • Tribuo - Provides tools for classification, regression, clustering, model development and interfaces with other libraries such as scikit-learn, pytorch and TensorFlow.
      • Smile - Statistical Machine Intelligence and Learning Engine provides a set of machine learning algorithms and a visualization library.
      • m2cgen - CLI tool to transpile models into native code.
      • JSAT - Algorithms for pre-processing, classification, regression, and clustering with support for multi-threaded execution. (GPL-3.0-only)
      • Oryx 2 - Framework for building real-time, large-scale machine learning applications. Includes end-to-end applications for collaborative filtering, classification, regression, and clustering.
      • Siddhi - Cloud native streaming and complex event processing engine.
      • Neureka - A lightweight, platform independent, OpenCL accelerated nd-array/tensor library.
      • Intelligent java - Seamlessly integrate with remote deep learning and language models programmatically.
      • Deeplearning4j - Distributed and multi-threaded deep learning library.
      • Apache Mahout - Scalable algorithms focused on collaborative filtering, clustering and classification.

    • Messaging

      • Apache ActiveMQ - Message broker that implements JMS and converts synchronous to asynchronous communication.
      • Apache Camel - Glues together different transport APIs via Enterprise Integration Patterns.
      • Apache Pulsar - Distributed pub/sub-messaging system.
      • Apache RocketMQ - Fast, reliable, and scalable distributed messaging platform.
      • Apache Qpid - Apache Qpid makes messaging tools that speak AMQP and support many languages and platforms.
      • Hermes - Fast and reliable message broker built on top of Kafka.
      • JeroMQ - Implementation of ZeroMQ.
      • EventBus - Simple publish/subscribe event bus.
      • Nakadi - Provides a RESTful API on top of Kafka.
      • RabbitMQ Java client - RabbitMQ client.
      • Smack - Cross-platform XMPP client library.
      • NATS client - NATS client.
      • Aeron - Efficient, reliable, unicast and multicast message transport.
      • Deezpatch - Simple, lightweight, and performant dispatch library for decoupling messages (requests and events) and message handlers.
      • AutoMQ - AutoMQ is a cloud-native, serverless reinvented Kafka that is easily scalable, manage-less and cost-effective.
      • Apache Pulsar - Distributed pub/sub-messaging system.
      • Apache RocketMQ - Fast, reliable, and scalable distributed messaging platform.
      • Apache Qpid - Apache Qpid makes messaging tools that speak AMQP and support many languages and platforms.
      • Hermes - Fast and reliable message broker built on top of Kafka.

    • Microservice

      • ActiveRPC - Lightweight and fast library for complex high-load distributed applications and Memcached-like solutions.
      • Nacos - Dynamic service discovery, configuration and service management platform for building cloud native applications.
      • Quarkus - Kubernetes stack tailored for the HotSpot and Graal VM.
      • OpenAI-Java - Java libraries for using OpenAI's GPT-3 API.
      • Eureka - REST-based service registry for resilient load balancing and failover.
      • Armeria - Asynchronous RPC/REST client/server library built on top of Java 8, Netty, HTTP/2, Thrift and gRPC.
      • consul-api - Client for the Consul API: a distributed, highly available and datacenter-aware registry/discovery service.
      • kubernetes-client - Client provides access to the full Kubernetes & OpenShift REST APIs via a fluent DSL.
      • Sentinel - Flow control component enabling reliability, resilience and monitoring for microservices.
      • JDA - Wrapping of the Discord REST API and its WebSocket events.
      • KeenType - Modernized version of a Java-based implementation of the New Typesetting System, which was heavily based on Donald E. Knuth's original TeX.
      • Helidon - Two-style approach for writing microservices: Functional-reactive and as an implementation of MicroProfile.
      • Micronaut - Modern full-stack framework with focus on modularity, minimal memory footprint and startup time.
      • Nacos - Dynamic service discovery, configuration and service management platform for building cloud native applications.
      • Quarkus - Kubernetes stack tailored for the HotSpot and Graal VM.

    • Miscellaneous

      • JBake - Static website generator.
      • JCuda - JCuda offers Java bindings for CUDA and CUDA-related libraries.
      • JObfuscator![c - Source code obfuscator.
      • Joda-Money - Basic currency and money classes and algorithms not provided by the JDK.
      • JPad - Snippet runner.
      • OpenRefine - Tool for working with messy data: cleaning, transforming, extending it with web services and linking it to databases.
      • Svix - Library for the Svix API to send webhooks and verify signatures.
      • Togglz - Implementation of the Feature Toggles pattern.
      • JBang - JBang makes it easy to use Java for scripting. It lets you use a single file for code and dependency management and allows you to run it directly.
      • Design Patterns - Implementation and explanation of the most common design patterns.
      • OctoLinker - Browser extension which allows to navigate through code on GitHub more efficiently.
      • Modern Java - A Guide to Java 8 - Popular Java 8 guide.
      • FizzBuzz Enterprise Edition - No-nonsense implementation of FizzBuzz made by serious businessmen for serious business purposes. (No explicit license)
      • jsweet - Source transpiler to TypeScript/JavaScript.
      • CQEngine - Ultra-fast, SQL-like queries on Java collections.
      • FF4J - Feature Flags for Java.
      • J2ObjC - Java-to-Objective-C translator for porting Android libraries to iOS.
      • JBot - Framework for building chatbots. (GPL-3.0-only)
      • Jimfs - In-memory file system.
      • Maven Wrapper - Analogue of Gradle Wrapper for Maven, allows building projects without installing maven.
      • MinimalFTP - Lightweight, small and customizable FTP server.
      • Modernizer - Detect uses of legacy Java APIs.
      • PipelinR - Small utility library for using handlers and commands with pipelines.
      • Polyglot for Maven - Extensions for Maven 3.3.1+ that allows writing the POM model in dialects other than XML.
      • Simple Java Mail - Mailing with a clean and fluent API.
      • Smooks - Framework for fragment-based message processing. (Apache-2.0 OR LGPL-3.0-or-later)
      • TypeTools - Tools for resolving generic types.
      • XMLBeam - Processes XML by using annotations or XPath within code.
      • yGuard - Obfuscation via renaming and shrinking.
      • JEmoji - An auto-generated emoji library that provides type-safe direct access to emojis and alias support for Discord, Slack, GitHub and many more features.
      • LittleProxy - High performance HTTP proxy atop Netty's event-based networking library.
      • webcam-capture - Library for using built-in and external webcams directly in Java.
      • IP2Location.io Java SDK - Wrapper for the IP2Location.io Geolocation API and the IP2WHOIS domain WHOIS API.
      • ISBN core - A small library that contains a representation object of ISBN-10 and ISBN-13 and tools to parse, validate and format one.
      • jOOX - Simple wrapper for the org.w3c.dom package, to allow for fluent XML document creation and manipulation with an API inspired by jQuery.
      • JCuda - JCuda offers Java bindings for CUDA and CUDA-related libraries.
      • RR4J - RR4J is a tool that records java bytecode execution and later allows developers to replay locally.
      • JBang - JBang makes it easy to use Java for scripting. It lets you use a single file for
      • JPad - Snippet runner.
      • Membrane Service Proxy - Open-source, reverse-proxy framework.

    • Mobile Development

      • Codename One - Cross-platform solution for writing native mobile apps. (GPL-2.0-only WITH Classpath-exception-2.0)
      • MobileUI - Cross-platform framework for developing mobile apps with native UI in Java and Kotlin.
      • Multi-OS Engine - Open-source, cross-platform engine to develop native mobile (iOS, Android, etc.) apps.
      • MobileUI - Cross-platform framework for developing mobile apps with native UI in Java and Kotlin.
      • Multi-OS Engine - Open-source, cross-platform engine to develop native mobile (iOS, Android, etc.) apps.

    • Monitoring

      • Glowroot - Open-source Java APM.
      • hippo4j - Dynamic and observable thread pool framework.
      • inspectIT - Captures detailed run-time information via hooks that can be changed on the fly. It supports tracing over multiple systems via the OpenTracing API and can correlate the data with end user monitoring.
      • Jolokia - JMX over REST.
      • zipkin - Distributed tracing system which gathers timing data needed to troubleshoot latency problems in microservice architectures.
      • Micrometer - Vendor-neutral metrics/observability facade for the most popular metrics/observability libraries.
      • Automon - Combines the power of AOP with monitoring and/or logging tools.
      • Failsafe Actuator - Out of the box monitoring of Failsafe Circuit Breaker in Spring-Boot environment.
      • jmxtrans - Connect to multiple JVMs and query them for their attributes via JMX. Its query language is based on JSON, which allows non-Java programmers to access the JVM attributes. Supports different output writes, including Graphite, Ganglia, and StatsD.
      • nudge4j - Remote developer console from the browser for Java 8 via bytecode injection.
      • Dropwizard Metrics - Expose metrics via JMX or HTTP and send them to a database.
      • Datadog ![c - Modern monitoring & analytics.
      • OpenTelemetry - Instrument, generate, collect, and export telemetry data to help you analyze your software’s performance and behavior.
      • Sentry ![c - Integration with [Sentry](https://github.com/getsentry/sentry), an application error tracking and performance analysis platform.
      • Stagemonitor - Open-source performance monitoring and transaction tracing for JVM apps.
      • Prometheus - Provides a multi-dimensional data model, DSL, autonomous server nodes and much more.
      • JavaMelody - Performance monitoring and profiling.
      • SPM ![c - Performance monitor with distributing transaction tracing for JVM apps.
      • Apitally - Simple, privacy-focused API monitoring, analytics and request logging for Spring Boot apps.
      • Micrometer Tracing - Vendor-neutral distributed tracing facade for the most popular tracer libraries.
      • HertzBeat - Real-time monitoring system with custom-monitor and agentless.
      • Jaeger client - Jaeger client.
      • Sysmon - Lightweight platform monitoring tool for Java VMs.
      • Pinpoint - Open-source APM tool.
      • Glowroot - Open-source Java APM.
      • Instrumental ![c - Real-time Java application performance monitoring. A commercial service with free development accounts.

    • Natural Language Processing

      • CoreNLP - Provides a set of fundamental tools for tasks like tagging, named entity recognition, and sentiment analysis. (GPL-3.0-or-later)
      • DKPro - Collection of reusable NLP tools for linguistic pre-processing, machine learning, lexical resources, etc.
      • LingPipe - Toolkit for tasks ranging from POS tagging to sentiment analysis.
      • CogCompNLP - Provides common annotators for plain text input. (Research and Academic Use License)
      • Hypherator - Java hyphenation library with iterator-like interface. Can be used out-of-the box - dictionaries for multiple languages are bundled in.
      • LingPipe - Toolkit for tasks ranging from POS tagging to sentiment analysis.

    • Networking

      • MINA - Abstract, event-driven async I/O API for network operations over TCP/IP and UDP/IP via Java NIO.
      • Undertow - Web server providing both blocking and non-blocking APIs based on NIO. Used as a network layer in WildFly. (LGPL-2.1-only)
      • Dubbo - High-performance RPC framework.
      • gRPC-java - RPC framework based on protobuf and HTTP/2.
      • KryoNet - Provides a clean and simple API for efficient TCP and UDP client/server network communication using NIO and Kryo.
      • sshj - Programmatically use SSH, SCP or SFTP.
      • ServiceTalk - Framework built on Netty with APIs tailored to specific protocols and support for multiple programming paradigms.
      • Comsat - Integrates standard Java web-related APIs with Quasar fibers and actors.
      • urnlib - Represent, parse and encode URNs, as in RFC 2141. (GPL-3.0-only)
      • Fluency - High throughput data ingestion logger to Fluentd and Fluent Bit.
      • TLS Channel - Implements a ByteChannel interface over SSLEngine, enabling easy-to-use (socket-like) TLS.
      • Drift - Easy-to-use, annotation-based library for creating Thrift clients and serializable types.
      • Commons-networking - Client for server-sent events (SSE).
      • Grizzly - NIO framework. Used as a network layer in Glassfish.

    • ORM

      • Apache Cayenne - Provides a clean, static API for data access. Also includes a GUI Modeler for working with database mappings, and DB reverse engineering and generation.
      • Ebean - Provides simple and fast data access.
      • EclipseLink - Supports a number of persistence standards: JPA, JAXB, JCA and SDO.
      • Hibernate - Robust and widely used, with an active community. (LGPL-2.1-only)
      • MyBatis - Couples objects with stored procedures or SQL statements.
      • MyBatis-Plus - A powerful enhanced toolkit of MyBatis for simplifying development.
      • ObjectiveSql - ActiveRecord ORM for rapid development and convention over configuration.
      • Permazen - Language-natural persistence layer.
      • Doma - Database access framework that verifies and generates source code at compile time using annotation processing as well as native SQL templates called two-way SQL.
      • SimpleFlatMapper - Simple database and CSV mapper.
      • Ebean - Provides simple and fast data access.
      • EclipseLink - Supports a number of persistence standards: JPA, JAXB, JCA and SDO.
      • Hibernate - Robust and widely used, with an active community. (LGPL-2.1-only)

    • PDF

      • Apache FOP - Creates PDFs from XSL-FO.
      • Apache PDFBox - Toolbox for creating and manipulating PDFs.
      • Dynamic Jasper - Abstraction layer to JasperReports. (LGPL-3.0-only)
      • Dynamic Jasper - Abstraction layer to JasperReports. (LGPL-3.0-only)
      • OpenPDF - Open-source iText fork. (LGPL-3.0-only & MPL-2.0)
      • Tabula - Extracts tables from PDF files.
      • Open HTML to PDF - Properly supports modern PDF standards based on flyingsaucer and Apache PDFBox.
      • flyingsaucer - XML/XHTML and CSS 2.1 renderer. (LGPL-2.1-or-later)
      • DynamicReports - Simplifies JasperReports. (LGPL-3.0-only)
      • JasperReports - Complex reporting engine. (LGPL-3.0-only)
      • Dynamic Jasper - Abstraction layer to JasperReports. (LGPL-3.0-only)
      • iText ![c - Creates PDF files programmatically.
      • Open HTML to PDF - Properly supports modern PDF standards based on flyingsaucer and Apache PDFBox.
      • Eclipse BIRT - Report engine for creating PDF and other formats (DOCX, XLSX, HTML, etc) using Eclipse-based visual editor.

    • Platform

      • BCEL - Byte Code Engineering Library - analyze, create, and manipulate Java class files.
      • BeanUtils - Easy-to-use wrappers around the Java reflection and introspection APIs.
      • BeanUtils2 - Redesign of Commons BeanUtils.
      • BSF - Bean Scripting Framework - interface to scripting languages, including JSR-223.
      • ClassScan - Find Class interfaces, methods, fields, and annotations without loading.
      • CLI - Command-line arguments parser.
      • CLI2 - Redesign of Commons CLI.
      • Codec - General encoding/decoding algorithms, e.g. phonetic, base64 or URL.
      • Collections - Extends or augments the Java Collections Framework.
      • Compress - Defines an API for working with tar, zip and bzip2 files.
      • Configuration - Reading of configuration/preferences files in various formats.
      • Convert - Commons-Convert aims to provide a single library dedicated to the task of converting an object of one type to another.
      • CSV - Component for reading and writing comma separated value files.
      • Daemon - Alternative invocation mechanism for unix-daemon-like java code.
      • DBCP - Database connection pooling services.
      • DbUtils - JDBC helper library.
      • Digester - XML-to-Java-object mapping utility.
      • Email - Library for sending e-mail from Java.
      • Exec - API for dealing with external process execution and environment management in Java.
      • FileUpload - File upload capability for your servlets and web applications.
      • Finder - Java library inspired by the UNIX find command.
      • Flatfile - Java library for working with flat data structures.
      • Graph - General purpose graph APIs and algorithms.
      • I18n - Adds the feature of localized message bundles that consist of one or many localized texts that belong together.
      • Id - Id is a component used to generate identifiers.
      • Imaging - Image library.
      • IO - Collection of I/O utilities.
      • Javaflow - Continuation implementation to capture the state of the application.
      • JCI - Java Compiler Interface.
      • JCS - Java Caching System.
      • Jelly - XML based scripting and processing engine.
      • Jexl - Expression language which extends the Expression Language of the JSTL.
      • JNet - JNet allows to use dynamically register url stream handlers through the java.net API.
      • JXPath - Utilities for manipulating Java Beans using the XPath syntax.
      • Lang - Provides extra functionality for classes in java.lang.
      • Logging - Wrapper around a variety of logging API implementations.
      • Monitoring - Monitoring aims to provide a simple but extensible monitoring solution for Java applications.
      • Nabla - Nabla provides automatic differentiation classes that can generate derivative of any function implemented in the Java language.
      • Net - Collection of network utilities and protocol implementations.
      • OpenPGP - Interface to signing and verifying data using OpenPGP.
      • Performance - Small framework for microbenchmark clients, with implementations for Commons DBCP and Pool.
      • Pipeline - Provides a set of pipeline utilities designed around work queues that run in parallel to sequentially process data objects.
      • Pool - Generic object pooling component.
      • RDF - Common implementation of RDF 1.1 that could be implemented by systems on the JVM.
      • RNG - Commons Rng provides implementations of pseudo-random numbers generators.
      • SCXML - Implementation of the State Chart XML specification aimed at creating and maintaining a Java SCXML engine.
      • Validator - Framework to define validators and validation rules in an xml file.
      • VFS - Virtual File System component for treating files, FTP, SMB, ZIP and such like as a single logical file system.
      • Weaver - Provides an easy way to enhance (weave) compiled bytecode.
      • CUBA Platform - High-level framework for developing enterprise applications with a rich web interface, based on Spring, EclipseLink and Vaadin.
      • Spring - Provides many packages for dependency injection, aspect-oriented programming, security, etc.
      • Light-4J - Fast, lightweight and productive microservices framework with built-in [security](https://github.com/networknt/light-oauth2/).
      • Orienteer - Open-source business application platform for rapid configuration/development of CRM, ERP, LMS and other applications.
      • Collections - Extends or augments the Java Collections Framework.
      • CSV - Component for reading and writing comma separated value files.
      • Email - Library for sending e-mail from Java.
      • IO - Collection of I/O utilities.
      • Lang - Provides extra functionality for classes in java.lang.
      • Pool - Generic object pooling component.
      • CUBA Platform - High-level framework for developing enterprise applications with a rich web interface, based on Spring, EclipseLink and Vaadin.

    • REST Frameworks

      • Elide - Opinionated framework for JSON- or GraphQL-APIs based on a JPA data model.
      • Jersey - JAX-RS reference implementation.
      • Rapidoid - Simple, secure and extremely fast framework consisting of an embedded HTTP server, GUI components and dependency injection.
      • RESTEasy - Fully certified and portable implementation of the JAX-RS specification.
      • Spark - Sinatra inspired framework.
      • Crnk - Implementation of the JSON API specification to build resource-oriented REST endpoints with sorting, filtering, paging, linking, object graphs, type-safety, bulk updates, integrations and more.
      • Swagger - Standard, language-agnostic interface to REST APIs.
      • Crnk - Implementation of the JSON API specification to build resource-oriented REST endpoints with sorting, filtering, paging, linking, object graphs, type-safety, bulk updates, integrations and more.
      • Crnk - Implementation of the JSON API specification to build resource-oriented REST endpoints with sorting, filtering, paging, linking, object graphs, type-safety, bulk updates, integrations and more.
      • Crnk - Implementation of the JSON API specification to build resource-oriented REST endpoints with sorting, filtering, paging, linking, object graphs, type-safety, bulk updates, integrations and more.
      • Crnk - Implementation of the JSON API specification to build resource-oriented REST endpoints with sorting, filtering, paging, linking, object graphs, type-safety, bulk updates, integrations and more.
      • Crnk - Implementation of the JSON API specification to build resource-oriented REST endpoints with sorting, filtering, paging, linking, object graphs, type-safety, bulk updates, integrations and more.
      • Crnk - Implementation of the JSON API specification to build resource-oriented REST endpoints with sorting, filtering, paging, linking, object graphs, type-safety, bulk updates, integrations and more.
      • Crnk - Implementation of the JSON API specification to build resource-oriented REST endpoints with sorting, filtering, paging, linking, object graphs, type-safety, bulk updates, integrations and more.
      • openapi-generator - Allows generation of API client libraries, SDKs, server stubs, documentation and configuration automatically given an OpenAPI Spec.
      • Dropwizard - Opinionated framework for setting up modern web applications with Jetty, Jackson, Jersey and Metrics.
      • rest.li - Framework for building robust, scalable RESTful architectures using typesafe bindings and asynchronous, non-blocking IO with an end-to-end developer workflow that promotes clean practices, uniform interface design and consistent data modeling.
      • springdoc-openapi - Automates the generation of API documentation using Spring Boot projects.
      • RestExpress - Thin wrapper on the JBoss Netty HTTP stack that provides scaling and performance.
      • Microserver - Convenient, extensible microservices plugin system for Spring & Spring Boot. With more than 30 plugins and growing, it supports both micro-monolith and pure microservices styles.
      • Restlet Framework - Pioneering framework with powerful routing and filtering capabilities, and a unified client and server API.
      • Crnk - Implementation of the JSON API specification to build resource-oriented REST endpoints with sorting, filtering, paging, linking, object graphs, type-safety, bulk updates, integrations and more.
      • Rapidoid - Simple, secure and extremely fast framework consisting of an embedded HTTP server, GUI components and dependency injection.
      • Elide - Opinionated framework for JSON- or GraphQL-APIs based on a JPA data model.
      • RESTEasy - Fully certified and portable implementation of the JAX-RS specification.

    • Science

      • BioJava - Facilitates processing biological data by providing algorithms, file format parsers, sequencing and 3D visualization commonly used in bioinformatics.
      • DataMelt - Environment for scientific computation, data analysis and data visualization. (GPL-3.0-or-later)
      • GraphStream - Library for modeling and analyzing dynamic graphs.
      • JFreeChart - 2D chart library for Swing, JavaFX and server-side applications. (LGPL-2.1-only)
      • Orekit - A low level space flight dynamics library providing basic elements (orbits, dates, attitude, frames...) and various algorithms (conversions, propagations, pointing...) to handle them.
      • Tablesaw - Includes a data-frame, an embedded column store, and hundreds of methods to transform, summarize, or filter data.
      • Morpheus - Provides a versatile two-dimensional memory efficient tabular data structure called a DataFrame to enable efficient in-memory analytics for scientific computing on the JVM.
      • JGraphT - Graph library that provides mathematical graph-theory objects and algorithms.
      • Orson-Charts - Generates a wide variety of 3D charts that can be displayed with Swing and JavaFX or exported to PDF, SVG, PNG and JPEG. (GPL-3.0-only)
      • XChart - Light-weight library for plotting data. Many customizable chart types are available.
      • Chart-FX - Scientific charting library with focus on performance optimised real-time data visualisation at 25 Hz update rates for large data sets.
      • Erdos - Modular, light and easy graph framework for theoretic algorithms.
      • JGraphX - Library for visualizing (mainly Swing) and interacting with node-edge graphs.
      • LogicNG - Library for creating, manipulating and solving Boolean and Pseudo-Boolean formulas.
      • Mines Java Toolkit - Library for geophysical scientific computation, visualization and digital signal analysis.
      • jSciPy - jSciPy is a Java library designed for scientific computing, offering functionalities inspired by popular scientific computing libraries. It currently provides modules for signal processing, including Butterworth filters, peak finding algorithms, and an RK4 solver for ordinary differential equations.
      • JFreeChart - 2D chart library for Swing, JavaFX and server-side applications. (LGPL-2.1-only)
      • Apache Lucene - High-performance, full-featured, cross-platform, text search engine library.
      • Apache Solr - Enterprise search engine optimized for high-volume traffic.
      • Elasticsearch - Distributed, multitenant-capable, full-text search engine with a RESTful web interface and schema-free JSON documents.
      • Indexer4j - Simple and light full text indexing and searching library.
      • Elasticsearch - Distributed, multitenant-capable, full-text search engine with a RESTful web interface and schema-free JSON documents.
      • Apache Solr - Enterprise search engine optimized for high-volume traffic.
      • Apache Lucene - High-performance, full-featured, cross-platform, text search engine library.

    • Server

      • Apache Tomcat - Robust, all-round server for Servlet and JSP.
      • Apache TomEE - Tomcat plus Java EE.
      • WildFly - Formerly known as JBoss and developed by Red Hat with extensive Java EE support. (LGPL-2.1-only)
      • nanohttpd - Tiny, easily embeddable HTTP server.
      • Jetty - Provides a Web server and javax.servlet container, plus support for HTTP/2, WebSocket, OSGi, JMX, JNDI, JAAS and many other integrations.
      • Apache TomEE - Tomcat plus Java EE.
      • WildFly - Formerly known as JBoss and developed by Red Hat with extensive Java EE support. (LGPL-2.1-only)

    • Template Engine

      • Freemarker - Library to generate text output (HTML web pages, e-mails, configuration files, source code, etc.) based on templates and changing data.
      • Pebble - Inspired by Twig and separates itself with its inheritance feature and its easy-to-read syntax. It ships with built-in autoescaping for security and it includes integrated support for internationalization.
      • Thymeleaf - Aims to be a substitute for JSP and works for XML files.
      • StringTemplate - Template engine for generating source code, web pages, emails, or any other formatted text output.
      • Jade4J - Implementation of Pug (formerly known as Jade).
      • Rocker - Optimized, memory efficient and speedy template engine producing statically typed, plain objects.
      • jstachio - Typesafe Mustache templating engine.
      • jte - Compiles to classes, and uses an easy syntax, several features to make development easier and provides fast execution and a small footprint.
      • Jamal - Extendable template engine embedded into Maven/JavaDoc, supporting multiple extensions (Groovy, Ruby, JavaScript, JShell, PlantUml) with support for snippet handling.
      • Jtwig - Modular, configurable and fully tested template engine.
      • Handlebars.java - Logicless and semantic Mustache templates.
      • Freemarker - Library to generate text output (HTML web pages, e-mails, configuration files, source code, etc.) based on templates and changing data.
      • Pebble - Inspired by Twig and separates itself with its inheritance feature and its easy-to-read syntax. It ships with built-in autoescaping for security and it includes integrated support for internationalization.
      • Thymeleaf - Aims to be a substitute for JSP and works for XML files.

    • Testing

      • JGiven - Provides a fluent API which allows for simpler composition.
      • Apache JMeter - Functional testing and performance measurements.
      • Arquillian - Integration and functional testing platform for Java EE containers.
      • Citrus - Integration testing framework that focuses on both client- and server-side messaging.
      • JUnit - Common testing framework.
      • jqwik - Engine for property-based testing built on JUnit 5.
      • PIT - Fast mutation-testing framework for evaluating fault-detection abilities of existing JUnit or TestNG test suites.
      • Hamcrest - Matchers that can be combined to create flexible expressions of intent.
      • Truth - Google's fluent assertion and proposition framework.
      • pojo-tester - Automatically performs tests on basic POJO methods. (LGPL-3.0-only)
      • JMockit - Integration testing, API mocking and faking, and code coverage.
      • MockServer - Allows mocking of systems integrated with HTTPS.
      • WireMock - Stubs and mocks web services.
      • JSONAssert - Simplifies testing JSON strings.
      • Java Faker - Port of Ruby's fake data generator.
      • selenium - Browser automation framework and ecosystem.
      • Mockito - Mocking framework that lets you write tests with a clean and simple API.
      • Awaitility - DSL for synchronizing asynchronous operations.
      • Moco - Concise web services for stubs and mocks.
      • Testcontainers - Provides throwaway instances of common databases, Selenium web browsers, or anything else that can run in a Docker container.
      • PowerMock - Mocks static methods, constructors, final classes and methods, private methods, and removal of static initializers.
      • Datafaker - Modern fake data generator forked from Java Faker.
      • REST Assured - DSL for easy testing of REST/HTTP services.
      • Cucumber - Provides a way to describe features in a plain language which customers can understand.
      • JMeter DSL.java - Load tests with JMeter as simple as a JUnit test.
      • Serenity BDD - Automated Acceptance testing and reporting library that works with Cucumber, JBehave and JUnit to make it easier to write high quality executable specifications.
      • AssertJ - Fluent assertions that improve readability.
      • EasyMock - EasyMock is a Java library that provides an easy way to use Mock Objects in unit testing.
      • Cukes-REST - Collection of Gherkin steps for REST-service testing using Cucumber.
      • WebTau - Test across REST-API, Graph QL, Browser, Database, CLI and Business Logic with consistent set of matchers and concepts.
      • J8Spec - Follows a Jasmine-like syntax.
      • Mockneat - Another fake data generator.
      • Selfie - Snapshot testing (inline and on disk).
      • ConcurrentUnit - Toolkit for testing multi-threaded and asynchronous applications.
      • XMLUnit - Simplifies testing for XML output.
      • raml-tester - Tests if a request/response matches a given RAML definition.
      • log-capture - Captures log entries and provides assertions for unit and integration testing.
      • Hoverfly Java - Native bindings for Hoverfly, a proxy which allows you to simulate HTTP services.
      • JMock - JMock is a high-performance data generation and simulation component library implemented in Java.
      • Instancio - Automates data setup in unit tests by generating fully-populated, reproducible objects. Includes JUnit 5 extension.
      • junit-dataprovider - TestNG-like data provider/runner for JUnit.
      • jFairy - Fake data generator.
      • Beanmother - Sets up beans from YAML fixtures.
      • Fixture Factory - Generates fake objects from a template.
      • AutoParams - Supports generating test data or combining scenarios for parameterized tests.
      • Lamdba Behave - Aims to provide a fluent API to write tests in long and descriptive sentences that read like plain English.
      • Randomized Testing - JUnit test runner and plugins for running JUnit tests with pseudo-randomness.
      • weld-testing - Set of test framework extensions (JUnit 4, JUnit 5, Spock) to enhance the testing of CDI components via Weld. Supports Weld 5.
      • JsonUnit - Library that simplifies JSON comparison in tests.
      • LogCaptor - Captures log entries for unit testing purposes.
      • ConsoleCaptor - Captures console output for unit testing purposes.
      • Mutability Detector - Reports whether instances of a given class are immutable.
      • Stebz - Multi-approach framework for test steps managing.
      • Karate - DSL that combines API test-automation, mocks and performance-testing making testing REST/HTTP services easy.
      • cdi-test - JUnit extension for easy and efficient testing of CDI components.
      • JMockit - Integration testing, API mocking and faking, and code coverage.
      • GreenMail - In-memory email server for integration testing. Supports SMTP, POP3 and IMAP including SSL. (GPL-2.0-only)
      • junit-pioneer - JUnit 5 extension pack, pushing the frontiers on Jupiter.
      • JUnit - Common testing framework.
      • Pact JVM - Consumer-driven contract testing.
      • Hamcrest - Matchers that can be combined to create flexible expressions of intent.
      • JBehave - Extensively configurable framework that describes stories.
      • JGiven - Provides a fluent API which allows for simpler composition.
      • Apache JMeter - Functional testing and performance measurements.
      • BitDive ![c - Zero-code integration testing platform that generates tests from runtime application behavior.
      • Citrus - Integration testing framework that focuses on both client- and server-side messaging.
      • jqwik - Engine for property-based testing built on JUnit 5.
      • PIT - Fast mutation-testing framework for evaluating fault-detection abilities of existing JUnit or TestNG test suites.
      • JSONAssert - Simplifies testing JSON strings.
      • Truth - Google's fluent assertion and proposition framework.
      • pojo-tester - Automatically performs tests on basic POJO methods. (LGPL-3.0-only)
      • MockServer - Allows mocking of systems integrated with HTTPS.
      • WireMock - Stubs and mocks web services.

    • Web Crawling

      • Apache Nutch - Highly extensible, highly scalable web crawler for production environments.
      • jsoup - Scrapes, parses, manipulates and cleans HTML.
      • webmagic - Scalable crawler with downloading, url management, content extraction and persistent.
      • Crawler4j - Simple and lightweight web crawler.
      • StormCrawler - SDK for building low-latency and scalable web crawlers.
      • Apache Nutch - Highly extensible, highly scalable web crawler for production environments.

    • Web Frameworks

      • ActiveJ - Lightweight asynchronous framework built from the ground up for developing high-performance web applications.
      • Apache Tapestry - Component-oriented framework for creating dynamic, robust, highly scalable web applications.
      • Apache Wicket - Component-based web application framework similar to Tapestry, with a stateful GUI.
      • Bootique - Minimally opinionated framework for runnable apps.
      • Firefly - Asynchronous framework for rapid development of high-performance web application.
      • Javalin - Microframework for web applications.
      • Jooby - Scalable, fast and modular micro-framework that offers multiple programming models.
      • Ninja - Full-stack web framework.
      • Pippo - Small, highly modularized, Sinatra-like framework.
      • Play - Built on Akka, it provides predictable and minimal resource consumption (CPU, memory, threads) for highly-scalable applications in Java and Scala.
      • PrimeFaces - JSF framework with both free and commercial/support versions and frontend components.
      • Ratpack - Set of libraries that facilitate fast, efficient, evolvable and well-tested HTTP applications.
      • Vaadin - Event-driven framework that uses standard web components. Server-side architecture with Ajax on the client side.
      • Blade - Lightweight, modular framework that aims to be elegant and simple.
      • Erupt - Annotation-Driven Low-Code & JPA Visualization
      • Takes - Opinionated web framework which is built around the concepts of True Object-Oriented Programming and immutability.
      • Firefly - Asynchronous framework for rapid development of high-performance web application.
      • Pippo - Small, highly modularized, Sinatra-like framework.
      • WebForms Core - A technology for managing HTML tags from the server.
      • PrimeFaces - JSF framework with both free and commercial/support versions and frontend components.
      • Jooby - Scalable, fast and modular micro-framework that offers multiple programming models.
      • Ratpack - Set of libraries that facilitate fast, efficient, evolvable and well-tested HTTP applications.
      • Vaadin - Full-stack open-source Java framework that simplifies web app development. Build complex, interactive applications with Java alone, and enhance with TypeScript and React components, without needing deep JavaScript, CSS, or HTML expertise.
      • ActiveJ - Lightweight asynchronous framework built from the ground up for developing high-performance web applications.
      • Apache Tapestry - Component-oriented framework for creating dynamic, robust, highly scalable web applications.
      • Apache Wicket - Component-based web application framework similar to Tapestry, with a stateful GUI.
      • Bootique - Minimally opinionated framework for runnable apps.
      • Ninja - Full-stack web framework.

    • Workflow Orchestration Engines

      • Cadence - Stateful code platform from Uber.
      • Temporal - Microservice orchestration platform, forked from Cadence but gRPC based.
      • flowable - Compact and efficient workflow and business process management platform.
      • Cadence - Stateful code platform from Uber.
      • Temporal - Microservice orchestration platform, forked from Cadence but gRPC based.

    • Serialization

      • Fury - Blazing fast object graph serialization framework powered by JIT and zero-copy.
      • FlatBuffers - Memory-efficient serialization library that can access serialized data without unpacking and parsing it.
      • Kryo - Fast and efficient object graph serialization framework.
      • MessagePack - Efficient binary serialization format.
      • PHP Serializer - Serializing objects in the PHP serialization format.
      • FST - JDK-compatible, high-performance object graph serialization.
      • Fury - Blazing fast object graph serialization framework powered by JIT and zero-copy.

    • Financial

      • Cassandre - Trading bot framework.
      • Parity - Platform for trading venues.
      • Philadelphia - Low-latency financial information exchange.
      • Square - Integration with the Square API.
      • Stripe - Integration with the Stripe API.
      • ta4j - Library for technical analysis.

    • Version Managers

      • jenv - Java Version Manager inspired by rbenv. Can configure globally or per project. Tested on Debian and macOS.
      • jabba - Java Version Manager inspired by nvm. Supports macOS, Linux and Windows.
      • SDKMan - Java Version Manager inspired by RVM and rbenv. Supports UNIX-based platforms and Windows.

    • Architecture

      • ArchUnit - Test library for specifying and asserting architecture rules.
      • jMolecules - Annotations and interfaces to express design and architecture concepts in code.

    • Bean Mapping

      • MapStruct - Code generator that simplifies mappings between different bean types, based on a convention-over-configuration approach.
      • dOOv - Provides fluent API for typesafe domain model validation and mapping. It uses annotations, code generation and a type safe DSL to make bean validation and mapping fast and easy.
      • JMapper - Uses byte code manipulation for lightning-fast mapping. Supports annotations and API or XML configuration.
      • ModelMapper - Intelligent object mapping library that automatically maps objects to each other.
      • Orika - JavaBean-mapping framework that recursively copies (among other capabilities) data from one object to another.
      • reMap - Lambda and method handle-based mapping which requires code and not annotations if objects have different names.
      • Selma - Annotation processor-based bean mapper.
      • dOOv - Provides fluent API for typesafe domain model validation and mapping. It uses annotations, code generation and a type safe DSL to make bean validation and mapping fast and easy.
      • Selma - Annotation processor-based bean mapper.

    • Job Scheduling

      • shedlock - Makes sure that your scheduled tasks are executed at most once at the same time. If a task is being executed on one node, it acquires a lock which prevents execution of the same task from another node or thread.
      • JobRunr - Job scheduling library which utilizes lambdas for fire-and-forget, delayed and recurring jobs. Guarantees execution by single scheduler instance using optimistic locking. Has features for persistence, minimal dependencies and is embeddable.
      • Quartz - Feature-rich, open source job scheduling library that can be integrated within virtually any Java application.
      • Sundial - Lightweight framework to simply define jobs, define triggers and start the scheduler.
      • Wisp - Simple library with minimal footprint and straightforward API.
      • db-scheduler - Persistent and cluster-friendly scheduler.
      • easy-batch - Set up batch jobs with simple processing pipelines. Records are read in sequence from a data source, processed in pipeline and written in batches to a data sink.

    • Date and Time

      • ThreeTen-Extra - Additional date-time classes that complement those in JDK 8.
      • iCal4j - Parse and build iCalendar [RFC 5545](https://tools.ietf.org/html/rfc5545) data models.
      • Time4J - Advanced date and time library. (LGPL-2.1-only)
      • Jollyday - Determines the holidays for a given year, country/name and eventually state/region.

    • Native

      • JNA - Work with native libraries without writing JNI. Also provides interfaces to common system libraries.
      • JavaCPP - Provides efficient and easy access to native C++.
      • native-lib-loader - Native library loader for extracting and loading native libraries from Java.
      • Aparapi - Converts bytecode to OpenCL which allows execution on GPUs.
      • JNR - Work with native libraries without writing JNI. Also provides interfaces to common system libraries. Same goals as JNA, but faster, and serves as the basis for the upcoming [Project Panama](http://openjdk.java.net/projects/panama).

    • Build

      • Buck - Encourages the creation of small, reusable modules consisting of code and resources.
      • Buck2 - Encourages the creation of small, reusable modules consisting of code and resources.
      • Bazel - Tool from Google that builds code quickly and reliably.
      • Gradle - Incremental builds programmed via Groovy instead of declaring XML. Works well with Maven's dependency management.

    • Hypermedia Types

      • JSON-LD - JSON-LD implementation.
      • Siren4J - Library for the Siren specification.
      • Spring HATEOAS - Standalone and Spring support for building hypermedia-based APIs using HAL, HAL FORMS, Collection+JSON, ALPS and UBER.
      • hate - Builds hypermedia-friendly objects according to HAL specification.

    • Artificial Intelligence

      • LangChain4j - Simplifies integration of LLMs with unified APIs and a comprehensive toolbox.
      • MCP Java SDK - Enables applications to interact with AI models and tools through a standardized interface (i.e. Model Context Protocol), supporting both synchronous and asynchronous communication patterns.
      • simple-openai - Library to use the OpenAI API (and compatible ones) in the simplest possible way.

    • Cloud

    • Decentralization

    • Processes

      • ch.vorburger.exec - Convenient API around Apache Commons Exec.
      • zt-exec - Provides a unified API to Apache Commons Exec and ProcessBuilder.
      • zt-process-killer - Stops processes started from Java or the system processes via PID.

    • Pathfinding

      • Pathetic - A highly configurable 3D A\* pathfinding library that uses specific optimizations for high performance.
Programming Languages
Java 351 HTML 8 Kotlin 6 C++ 3 Shell 2 PHP 1 JavaScript 1 Gherkin 1 Rust 1 java 1
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Sub Categories
Testing 73 People 68 Platform 60 Database 42 Miscellaneous 40 Websites 30 Web Frameworks 28 Security 27 Monitoring 26 REST Frameworks 25 Utility 22 Messaging 19 Code Generators 18 Science 17 JSON 17 Distributed Applications 17 Microservice 15 Logging 15 Related Awesome Lists 15 PDF 14 Machine Learning 14 Distribution 14 Template Engine 14 Networking 14 JVM and JDK 14 Code Analysis 13 ORM 13 Bytecode Manipulation 13 Geospatial 12 Development 12 Configuration 12 Data Structures 11 Podcasts and Screencasts 10 HTTP Clients 10 Dependency Injection 10 Game Development 9 Bean Mapping 9 Performance analysis 9 CLI 9 Imagery 9 Formal Verification 9 Functional Programming 8 Introspection 7 Search 7 Server 7 Serialization 7 Influential Books 7 Job Scheduling 7 Financial 6 Document Processing 6 Constraint Satisfaction Problem Solver 6 Caching 6 CSV 6 IDE 6 GUI 6 Natural Language Processing 6 PaaS 6 Web Crawling 6 High Performance 6 Reactive libraries 5 Native 5 Distributed Transactions 5 Workflow Orchestration Engines 5 Mobile Development 5 Build 4 Date and Time 4 Hypermedia Types 4 Compiler-compiler 4 Code Coverage 3 Version Managers 3 Artificial Intelligence 3 Processes 3 Computer Vision 3 Frontends 2 Cluster Management 2 Communities 2 Cloud 2 Architecture 2 Pathfinding 1 Decentralization 1
Keywords
java 210 android 15 kotlin 15 spring-boot 15 testing 13 microservices 13 spring 13 monitoring 12 static-analysis 11 jvm 11 json 9 java-library 9 database 9 http 9 javascript 8 awesome 8 machine-learning 7 rest-api 7 xml 7 rpc 7 annotation-processor 7 rest 7 python 7 library 6 sql 6 serialization 6 cloud-native 6 jdbc 6 javafx 6 high-performance 6 metrics 6 static-code-analysis 6 awesome-list 6 java-8 6 java8 5 scheduler 5 configuration 5 framework 5 orm 5 gradle 5 cpp 5 grpc 5 c 5 test-automation 5 groovy 5 junit 5 generator 4 sdk 4 api 4 spring-boot-starter 4