Ecosyste.ms: Awesome

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

https://github.com/datafaker-net/datafaker

Generating fake data for the JVM (Java, Kotlin, Groovy) has never been easier!
https://github.com/datafaker-net/datafaker

faker testing

Last synced: about 2 months ago
JSON representation

Generating fake data for the JVM (Java, Kotlin, Groovy) has never been easier!

Lists

README 

        

# Data Faker



[![Maven Status](https://maven-badges.herokuapp.com/maven-central/net.datafaker/datafaker/badge.svg?style=flat)](http://mvnrepository.com/artifact/net.datafaker/datafaker)

[![License](http://img.shields.io/:license-apache-brightgreen.svg)](http://www.apache.org/licenses/LICENSE-2.0.html)

[![codecov](https://codecov.io/gh/datafaker-net/datafaker/branch/main/graph/badge.svg?token=FJ6EXMUTFD)](https://codecov.io/gh/datafaker-net/datafaker)



This library is a modern fork of [java-faker](https://github.com/DiUS/java-faker) with up to date libraries and several newly added Fake Generators. 



Datafaker 2.x has Java 17 as the minimum requirement. 



*If Java 17 is not an option for you, you can choose to use Datafaker 1.x. Datafaker 1.x is built on Java 8, but this version is no longer maintained. We recommend all users to upgrade to Datafaker 2.x.*



This library generates fake data, similar to other fake data generators, such as:



* Ruby's [faker](https://github.com/stympy/faker) gem

* Perl's [Data::Faker](https://metacpan.org/pod/Data::Faker) library

* Python [faker](https://faker.readthedocs.io/en/master/) package

* PHP [faker](https://fakerphp.github.io/) library

* Javascript [Faker.js](https://github.com/faker-js/faker) library



It's useful when you're developing a new project and need some pretty data for showcase.



## Usage



In the pom.xml, add the following fragment to the `dependencies` section:



```xml



    net.datafaker

    datafaker

    2.1.0



```



For Gradle users, add the following to your build.gradle file.



```groovy

dependencies {

    implementation 'net.datafaker:datafaker:2.1.0'

}



```



You can also use the snapshot version (`2.1.1-SNAPSHOT`), which automatically gets published

after every push to the main branch of this repository. Binary repository URL for snapshots download is

`https://s01.oss.sonatype.org/content/repositories/snapshots/`.



### Get started



In your Java code:



```java

Faker faker = new Faker();



String name = faker.name().fullName(); // Miss Samanta Schmidt

String firstName = faker.name().firstName(); // Emory

String lastName = faker.name().lastName(); // Barton



String streetAddress = faker.address().streetAddress(); // 60018 Sawayn Brooks Suite 449

```



Or in your Kotlin code:



```kotlin

val faker = Faker()



val name = faker.name().fullName() // Miss Samanta Schmidt

val firstName = faker.name().firstName() // Emory

val lastName = faker.name().lastName() // Barton



val streetAddress = faker.address().streetAddress() // 60018 Sawayn Brooks Suite 449

```



JShell

```

# from project root folder

jshell --class-path $(ls -d target/*.jar | tr '\n' ':')

|  Welcome to JShell -- Version 17.0.4

|  For an introduction type: /help intro



jshell> import net.datafaker.Faker;



jshell> var faker = new Faker();

faker ==> net.datafaker.Faker@c4437c4



jshell> faker.address().city();

$3 ==> "Brittneymouth"



jshell> faker.name().fullName();

$5 ==> "Vernie Schmidt"

```



### Expressions



```java

Faker faker = new Faker();

faker.expression("#{letterify 'test????test'}"); // testqwastest

faker.expression("#{numerify '#test#'}"); // 3test5

faker.expression("#{templatify 'test','t','q','@'}"); // @esq

faker.expression("#{examplify 'test'}"); // ghjk

faker.expression("#{regexify '[a-z]{4,10}'}"); // wbevoa

faker.expression("#{options.option '23','2','5','$','%','*'}"); // *

faker.expression("#{date.birthday 'yy DDD hh:mm:ss'}"); // 61 327 08:11:45

faker.expression("#{csv '1','name_column','#{Name.first_name}','last_name_column','#{Name.last_name}'}");

// "name_column","last_name_column"

// "Sabrina","Kihn"

faker.expression("#{json 'person','#{json ''first_name'',''#{Name.first_name}'',''last_name'',''#{Name.last_name}''}','address','#{json ''country'',''#{Address.country}'',''city'',''#{Address.city}''}'}");

// {"person": {"first_name": "Barbie", "last_name": "Durgan"}, "address": {"country": "Albania", "city": "East Catarinahaven"}}

```

also more examples at https://www.datafaker.net/documentation/expressions/



### Collections

```java

Faker faker = new Faker();

List names = faker.collection(

                              () -> faker.name().firstName(),

                              () -> faker.name().lastName())

                         .len(3, 5)

                         .generate();

System.out.println(names);

// [Skiles, O'Connell, Lorenzo, West]

```

more examples about that at https://www.datafaker.net/documentation/sequences/



### Streams

```java

Faker faker = new Faker();

// generate an infinite stream

Stream names = faker.stream(

                              () -> faker.name().firstName(),

                              () -> faker.name().lastName())

                         .generate();

```



### Formats



#### Schema

There are 2 ways of data generation in specific formats

1. Generate it from scratch

2. There is already a sequence of objects and we could extract from them some values and return it in specific format



For both cases we need a `Schema` which could describe fields and a way of data generation.

In case of generation from scratch `Suppliers` are enough, in case of transformation `Functions` are required

#### CSV



```java

// transformer could be the same for both

CsvTransformer transformer =

        CsvTransformer.builder().header(true).separator(",").build();

// Schema for from scratch

Schema fromScratch =

    Schema.of(field("firstName", () -> faker.name().firstName()),

        field("lastname", () -> faker.name().lastName()));

System.out.println(transformer.generate(fromScratch, 2));

// POSSIBLE OUTPUT

// "first_name" ; "last_name"

// "Kimberely" ; "Considine"

// "Mariela" ; "Krajcik"

// ----------------------

// Schema for transformations

Schema schemaForTransformations =

    Schema.of(field("firstName", Name::firstName),

        field("lastname", Name::lastName));

// Here we pass a collection of Name objects and extract first and lastnames from each element

System.out.println(

    transformer.generate(

        faker.collection(faker::name).maxLen(2).generate(), schemaForTransformations));

// POSSIBLE OUTPUT

// "first_name" ; "last_name"

// "Kimberely" ; "Considine"

// "Mariela" ; "Krajcik"

```



#### JShell



```

# from project root folder

jshell --class-path $(ls -d target/*.jar | tr '\n' ':')

|  Welcome to JShell -- Version 17.0.4

|  For an introduction type: /help intro



jshell> import net.datafaker.Faker;



jshell> import net.datafaker.providers.base.Name;



jshell> import net.datafaker.transformations.Schema;



jshell> import net.datafaker.transformations.CsvTransformer;



jshell> import static net.datafaker.transformations.Field.field;



jshell> var faker = new Faker();

faker ==> net.datafaker.Faker@c4437c4



jshell> Schema fromScratch =

   ...>     Schema.of(field("firstName", () -> faker.name().firstName()),

   ...>         field("lastname", () -> faker.name().lastName()));

fromScratch ==> net.datafaker.transformations.Schema@306a30c7



jshell> CsvTransformer transformer =

   ...>     CsvTransformer.builder().header(false).separator(",").build();

transformer ==> net.datafaker.transformations.CsvTransformer@506c589e



jshell> System.out.println(transformer.generate(fromScratch, 2));

"firstName","lastname"

"Darcel","Schuppe"

"Noelle","Smitham"

```



#### JSON



```java

Schema schema = Schema.of(

    field("firstName", () -> faker.name().firstName()),

    field("lastName", () -> faker.name().lastName())

    );



JsonTransformer transformer = JsonTransformer.builder().build();

String json = transformer.generate(schema, 2);

// [{"firstName": "Oleta", "lastName": "Toy"},

// {"firstName": "Gerard", "lastName": "Windler"}]

```

More complex examples and other formats like YAML, XML could be found at https://www.datafaker.net/documentation/formats/



### Unique Values



```java

Faker faker = new Faker();



// The values returned in the following lines will never be the same.

String firstUniqueInstrument = faker.unique().fetchFromYaml("music.instruments"); // "Flute"

String secondUniqueInstrument = faker.unique().fetchFromYaml("music.instruments"); // "Clarinet"

```

More examples can be found in https://www.datafaker.net/documentation/unique-values



### Custom provider



Add your own custom provider in your app following steps from https://www.datafaker.net/documentation/custom-providers/



Documentation

-----

[Getting started](https://www.datafaker.net/documentation/getting-started/).



Contributions

-------------

See [CONTRIBUTING.md](https://github.com/datafaker-net/datafaker/blob/main/CONTRIBUTING.md)



If this is your first time contributing then you may find it helpful to read [FIRST_TIME_CONTRIBUTOR.md](https://github.com/datafaker-net/datafaker/blob/main/FIRST_TIME_CONTRIBUTOR.md)



Providers

-----

The list below is not complete and shows only a part of available providers. To view the full list of providers, please follow the link: [Full list of providers](https://www.datafaker.net/documentation/providers/).



* Address

* Ancient

* Animal

* App

* Appliance

* Aqua Teen Hunger Force

* Artist

* Australia

* Avatar

* Aviation

* AWS

* Azure

* Babylon 5

* Back To The Future

* Barcode

* Baseball

* Basketball

* Battlefield 1  

* Beer

* Big Bang Theory

* Blood Type

* Bojack Horseman

* Book

* Bool

* Bossa Nova

* Brand

* Breaking Bad

* Brooklyn Nine-Nine

* Buffy

* Business

* CNPJ ([Brazilian National Registry of Legal Entities](https://en.wikipedia.org/wiki/CNPJ))

* CPF ([Brazilian individual taxpayer registry identification](https://en.wikipedia.org/wiki/CPF_number))

* Camera

* Cat

* Chuck Norris

* Clash of Clans

* Code

* Coin

* Color

* Commerce

* Community

* Company

* Compass

* Computer

* Control

* Country

* Credit Card Type

* Cricket

* Crypto

* Currency

* Date and Time

* DC Comics

* Demographic

* Departed

* Dessert

* Device

* Disease

* Doctor Who

* Dog

* Domain

* Doraemon

* Dragon Ball

* Driving License

* Dumb and Dumber

* Dune

* Durations

* Educator

* Elden Ring

* Elder Scrolls

* Electrical Components

* Emoji

* England Football

* Esports

* Fallout

* Family Guy

* Famous Last Words

* File

* Final Space

* Finance

* Food

* Formula 1 (:racing_car:)

* Friends

* Fullmetal Alchemist: Brotherhood

* Funny Name

* Futurama

* Game Of Thrones

* Garment Size

* Gender

* Ghostbusters

* Grateful Dead

* Greek Philosopher

* Hacker

* Harry Potter

* Hashing

* Hearthstone

* Heroes of the Storm

* Hey Arnold

* Hipster

* Hitchhiker's Guide To The Galaxy

* Hobbit

* Hobby

* Horse

* House

* How I Met Your Mother

* IdNumber

* Industry Segments

* Internet

* Job

* Joke

* K-pop (Korean popular music)

* Kaamelott

* Language Code

* League Of Legends

* Lebowski

* Locality

* Lord Of The Rings

* Lorem

* Marketing

* Marvel Snap

* Mass Effect

* Matz

* MBTI

* Measurement

* Medical

* Military

* Minecraft

* Money

* Money Heist

* Mood

* Mountaineering

* Mountains

* Movie

* Music

* Name

* Naruto

* Nation

* Nato Phonetic Alphabet

* Nigeria

* Number

* One Piece

* Options

* Oscar Movie

* Overwatch

* Passport

* Password

* Phone Number

* Photography

* Planet

* Pokemon

* Princess Bride

* Programming Language

* Red Dead Redemption 2

* Relationship Terms

* Resident Evil

* Restaurant

* Rick and Morty

* Robin

* Rock Band

* RuPaul's Drag Race

* Science

* Seinfeld

* Shakespeare

* Silicon Valley

* Simpsons

* Sip

* Size

* Slack Emoji

* Soul Knight

* Space

* StarCraft

* StarTrek

* Stock

* Studio Ghibli

* Subscription

* Super Mario

* Superhero

* Tea

* Team

* The IT Crowd

* Time

* Touhou

* Tron

* Twin Peaks

* Twitter

* University

* Vehicle

* Verb

* Volleyball

* Weather

* Witcher

* Yoda

* Zelda



Usage with Locales

-----



```java

Faker faker = new Faker(new Locale("YOUR_LOCALE"));

```



For example:



```java

new Faker(new Locale("en", "US")).address().zipCodeByState("CA"));

```



Supported Locales

-----

* ar

* bg

* ca

* ca-CAT

* cs

* da-DK

* de

* de-AT

* de-CH

* en

* en-AU

* en-au-ocker

* en-BORK

* en-CA

* en-GB

* en-IND

* en-MS

* en-NEP

* en-NG

* en-NZ

* en-PAK

* en-SG

* en-UG

* en-US

* en-ZA

* en-PH

* es

* es-MX

* fa

* fi-FI

* fr

* he

* hu

* in-ID

* it

* ja

* ko

* nb-NO

* nl

* pl

* pt

* pt-BR

* ru

* sk

* sv

* sv-SE

* tr

* uk

* vi

* zh-CN

* zh-TW



LICENSE

-------

Copyright (c) 2023 Datafaker.net See the LICENSE file for license rights and limitations.