Data Faker

This library is a modern fork of java-faker, built on Java 8, with up to date libraries and several newly added Fake Generators.

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

• Ruby's faker gem
• Perl's Data::Faker library
• Python faker package
• PHP faker library
• Javascript Faker.js 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:

<dependency>
    <groupId>net.datafaker</groupId>
    <artifactId>datafaker</artifactId>
    <version>1.7.0</version>
</dependency>

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

dependencies {
    implementation 'net.datafaker:datafaker:1.7.0'
}

You can also use the snapshot version (1.8.0-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:

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:

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

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

Faker faker = new Faker();
List<String> 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

Faker faker = new Faker();
// generate an infinite stream
Stream<String> 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

// transformer could be the same for both
CsvTransformer<Name> transformer =
        new CsvTransformer.CsvTransformerBuilder<Name>().header(true).separator(",").build();
// Schema for from scratch
Schema<Name, String> 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<Name, String> 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<Name> transformer =
   ...>     new CsvTransformer.CsvTransformerBuilder<Name>().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

Faker faker = new Faker();
String json = Format.toJson(
                faker.collection(faker::name)
                  .maxLen(2)
                  .build())
              .set("firstName", Name::firstName)
              .set("lastName", Name::lastName)
              .build()
              .generate();
// [{"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

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.

Contributions

See CONTRIBUTING.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.

• 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
• Breaking Bad
• Brooklyn Nine-Nine
• Buffy
• Business
• CNPJ (Brazilian National Registry of Legal Entities)
• CPF (Brazilian individual taxpayer registry identification)
• 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
• K-pop (Korean popular music)
• Kaamelott
• 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
• Pokemon
• Princess Bride
• Programming Language
• 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

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

For example:

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) 2022 DataFaker.net See the LICENSE file for license rights and limitations.