https://github.com/ralscha/constgen
Constant Generator
https://github.com/ralscha/constgen
annotation-processor java
Last synced: about 1 year ago
JSON representation
Constant Generator
- Host: GitHub
- URL: https://github.com/ralscha/constgen
- Owner: ralscha
- License: apache-2.0
- Created: 2015-09-25T06:01:19.000Z (almost 11 years ago)
- Default Branch: master
- Last Pushed: 2025-03-20T03:14:59.000Z (over 1 year ago)
- Last Synced: 2025-04-03T11:36:30.573Z (about 1 year ago)
- Topics: annotation-processor, java
- Language: Java
- Size: 354 KB
- Stars: 3
- Watchers: 3
- Forks: 3
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
## constgen
## Overview
*constgen* is a Java Annotation Processor that scans for classes annotated with ```org.springframework.data.mongodb.core.mapping.Document``` or
```org.mongodb.morphia.annotations.Entity```. For every annotated class *constgen* creates an additional Java class with the name **C***classname*. This new class contains class variables for every field from the origin class.
## Example
*Source class*
```
@Document
public class User {
private String id;
private String email;
private String passwordResetToken;
private Date passwordResetTokenValidUntil;
private boolean deleted;
}
```
*Generated class*
```
public final class CUser {
public static final String deleted = "deleted";
public static final String email = "email";
public static final String id = "id";
public static final String passwordResetToken = "passwordResetToken";
public static final String passwordResetTokenValidUntil = "passwordResetTokenValidUntil";
}
```
## Use Case
When you write queries with Morphia or Spring Data MongoDB you need to specify the fields with String parameters.
If you have a typo in a field name MongoDB will not complain because it is schemaless.
The C classes help you to make this process a little less error prone. In an IDE you will have code completion and it is more refactor friendly. When somebody removes or renames a field you will immediately see compiler errors.
*With String*
```
User user = mongoTemplate.findAndModify(
Query.query(Criteria.where("email").is("test@test.com")
.and("deleted").is(false)),
Update.update("passwordResetTokenValidUntil", new Date())
.set("passwordResetToken", "test_token"),
FindAndModifyOptions.options().returnNew(true), User.class);
```
*With C class*
```
User user = this.mongoTemplate.findAndModify(
Query.query(Criteria.where(CUser.email).is("test@test.com")
.and(CUser.deleted).is(false)),
Update.update(CUser.passwordResetTokenValidUntil, new Date())
.set(CUser.passwordResetToken, token),
FindAndModifyOptions.options().returnNew(true), User.class);
```
## Features
*constgen* ...
* requires Java 8 to run.
* scans for classes annotated with ```org.springframework.data.mongodb.core.mapping.Document``` or ```org.mongodb.morphia.annotations.Entity```.
* ignores ```transient``` fields.
* ignores ```static``` fields.
* ignores fields annotated with ```org.springframework.data.annotation.Transient``` or ```org.mongodb.morphia.annotations.Transient```.
* takes into account the annotations ```org.springframework.data.mongodb.core.mapping.Field``` and ```org.mongodb.morphia.annotations.Property``` and uses the value of the annotation as value for the String constant.
## Maven
To activate the annotation processor you add the library as a dependency to your pom.xml.
constgen does not need to present at runtime so the dependency can be marked as optional
and will not be included in an jar or war.
```
ch.rasc
constgen
1.0.3
true
```
Instead of ```true``` the provided scope ```provided``` can be specified.
It has the same effect and marks the library as a compile-time only dependency.
The [immutable](http://immutables.github.io) project has a good description
on how to [use annotation processors in Eclipse and IntelliJ](http://immutables.github.io/apt.html).
The Spring Boot Maven plugin includes dependencies that are optional or scope provided in the final jar.
To exclude constgen you need to add an exclude configuration.
```
org.springframework.boot
spring-boot-maven-plugin
ch.rasc
constgen
```
## Changelog
### 1.0.3 - January 30, 2016
* Resolves issue [#1](https://github.com/ralscha/constgen/issues/1)
### 1.0.2 - November 22, 2015
* Do not ignore transient fields. Spring Data Mongo stores these fields.
* Support annotations (Field and Transient) from [bsoncodec-apt](https://github.com/ralscha/bsoncodec-apt)
### 1.0.1 - October 29, 2015
* Ignore static fields
* Generate code the correct way with JavaFileObject
### 1.0.0 - September 26, 2015
* Initial release
## License
Code released under [the Apache license](http://www.apache.org/licenses/).
## Links
* [Spring Data MongoDB](http://projects.spring.io/spring-data-mongodb/)
* [Morphia](https://github.com/mongodb/morphia)
* [bsoncodec-apt](https://github.com/ralscha/bsoncodec-apt)
* [Mongo Java Driver](https://github.com/mongodb/mongo-java-driver)
* [MongoDB](https://www.mongodb.org/)