README

Fuel - Documentation
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Core
Support
Deserialization
Kotlinx-Serialization
Moshi
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v1.x.y
README
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The easiest HTTP networking library for Kotlin/Android.
You are looking at the documentation for 2.x.y.. If you are looking for the documentation for 1.x.y, checkout the 1.16.0 README.md​
Features
HTTP GET/POST/PUT/DELETE/HEAD/PATCH requests in a fluent style interface
Asynchronous and blocking requests
Download as a file
Upload files, Blobs, DataParts as multipart/form-data
Cancel asynchronous request
Debug logging / convert to cUrl call
Deserialization into POJO / POKO
Requests as coroutines​
API Routing
Installation
We offer maven and jitpack installations. Maven via bintray only has stable releases but jitpack can be used to build any branch, commit and version.
Maven
You can download and install Fuel with Maven and Gradle. The core package has the following dependencies:
Kotlin - ​
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​Result - 3.1.0
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  //core
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  implementation 'com.github.kittinunf.fuel:fuel:<latest-version>'
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  //packages
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  implementation 'com.github.kittinunf.fuel:<package>:<latest-version>'
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Make sure to include mavenCentral() in your repositories (jcenter() is deprecated, new releases starting from 2.2.3 are hosted on mavenCentral())
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repositories {
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  mavenCentral()
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}
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Each of the extensions / integrations has to be installed separately.
Package
Description
​fuel​
Core package
​fuel-android​
Android: Automatically invoke handler on Main Thread when using Android Module
​fuel-coroutines​
KotlinX: Execution with coroutines​
​fuel-forge​
Deserialization: Forge​
​fuel-gson​
(De)serialization: Gson​
​fuel-jackson​
Deserialization: Jackson​
​fuel-json​
Deserialization: Json​
​fuel-kotlinx-serialization​
(De)serialization: KotlinX Serialization​
​fuel-livedata​
Android Architectures: Responses as LiveData​
​fuel-moshi​
Deserialization: Moshi​
​fuel-reactor​
Reactive Programming: Responses as Mono (Project Reactor 3.x)
​fuel-rxjava​
Reactive Programming: Responses as Single (RxJava 2.x)
​fuel-stetho​
Utility: Debug utility for Android on Chrome Developer Tools, Stetho​
Jitpack
If you want a SNAPSHOT distribution, you can use Jitpack​
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repositories {
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  maven(url = "https://www.jitpack.io") {
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    name = "jitpack"
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  }
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}
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​
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dependencies {
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  //core
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  implementation(group = "com.github.kittinunf.fuel", name = "fuel", version = "-SNAPSHOT")
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  //packages
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  // replace <package> with the package name e.g. fuel-coroutines
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  implementation(group = "com.github.kittinunf.fuel", name = "<package>", version = "-SNAPSHOT")
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}
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or
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dependencies {
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  //core and/or packages
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  // replace <package> with the package name e.g. fuel-coroutines
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  listof("fuel", "<package>").forEach {
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    implementation(group = "com.github.kittinunf.fuel", name = it, version = "-SNAPSHOT")
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  }
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}
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Configuration
group is made up of com.github as well as username and project name
name is the subproject, this may be any of the packages listed in the installation instructions eg. fuel, fuel-coroutines, fuel-kotlinx-serialization, etc
version can be the latest master-SMAPSHOT or -SNAPSHOT which always points at the HEAD or any other branch, tag or commit hash, e.g. as listed on jitpack.io.
We recommend not using SNAPSHOT builds, but a specific commit in a specific branch (like a commit on master), because your build will then be stable.
Build time-out
Have patience when updating the version of fuel or building for the first time as jitpack will build it, and this may cause the request to jitpack to time out. Wait a few minutes and try again (or check the status on jitpack).
NOTE: do not forget to add the kotlinx repository when using coroutines or serialization
Forks
Jitpack.io also allows to build from fuel forks. If a fork's username is $yourname,
adjust group to com.github.$yourName.fuel
and look for version on https://jitpack.io/#$yourName/Fuel
Quick start
Fuel requests can be made on the Fuel namespace object, any FuelManager or using one of the String extension methods. If you specify a callback the call is async, if you don't it's blocking.
Async Usage Example
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import com.github.kittinunf.fuel.httpGet
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import com.github.kittinunf.result.Result
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​
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fun main(args: Array<String>) {
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​
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    val httpAsync = "https://httpbin.org/get"
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        .httpGet()
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        .responseString { request, response, result ->
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            when (result) {
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                is Result.Failure -> {
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                    val ex = result.getException()
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                    println(ex)
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                }
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                is Result.Success -> {
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                    val data = result.get()
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                    println(data)
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                }
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            }
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        }
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​
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    httpAsync.join()
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}
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Blocking Usage Example
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import com.github.kittinunf.fuel.httpGet
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import com.github.kittinunf.result.Result;
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​
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fun main(args: Array<String>) {
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​
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    val (request, response, result) = "https://httpbin.org/get"
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        .httpGet()
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        .responseString()
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​
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    when (result) {
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        is Result.Failure -> {
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            val ex = result.getException()
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            println(ex)
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        }
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        is Result.Success -> {
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            val data = result.get()
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            println(data)
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        }
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    }
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​
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}
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​
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// You can also use Fuel.get("https://httpbin.org/get").responseString { ... }
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// You can also use FuelManager.instance.get("...").responseString { ... }
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Fuel and the extension methods use the FuelManager.instance under the hood. You can use this FuelManager to change the default behaviour of all requests:
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FuelManager.instance.basePath = "https://httpbin.org"
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​
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"/get"
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  .httpGet()
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  .responseString { request, response, result -> /*...*/ }
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// This is a GET request to "https://httpbin.org/get"
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Detailed usage
Check each of the packages documentations or the Wiki for more features, usages and examples. Are you looking for basic usage on how to set headers, authentication, request bodies and more? fuel: Basic usage is all you need.
Basic functionality
​fuel: Basic usage​
​fuel-android: Android usage​
​fuel-coroutines: Execution with coroutines​
Responses
​fuel-livedata: Responses as LiveData​
​fuel-reactor: Responses as Mono​
​fuel-rxjava: Responses as Single​
(De)serialization
​fuel-forge: Deserialization with Forge​
​fuel-gson: (De)serialization with Gson​
​fuel-jackson: Deserialization with Jackson​
​fuel-json: Deserialization with Json​
​fuel-kotlinx-serialization: (De)serialization with KotlinX Serialization​
​fuel-moshi: Deserialization with Moshi​
Utility
​fuel-stetho : Debugging bridge for Android with Stetho​
Other libraries
If you like Fuel, you might also like other libraries of mine;
​Result - The modelling for success/failure of operations in Kotlin
​Fuse - A simple generic LRU memory/disk cache for Android written in Kotlin
​Forge - Functional style JSON parsing written in Kotlin
​ReactiveAndroid - Reactive events and properties with RxJava for Android SDK
Credits
Fuel is brought to you by contributors.
Licenses
Fuel is released under the MIT license.
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Fuel
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