Coroutines

The coroutines extension package for Fuel.

Installation

You can download and install fuel-coroutines with Maven and Gradle. The coroutines package has the following dependencies:

  • Fuel

  • KotlinX Coroutines: 1.1.1

Gradle

implementation 'com.github.kittinunf.fuel:fuel:<latest-version>'
implementation 'com.github.kittinunf.fuel:fuel-coroutines:<latest-version>'

Maven

<dependency>
<groupId>com.github.kittinunf.fuel</groupId>
<artifactId>fuel</artifactId>
<version>[LATEST_VERSION]</version>
</dependency>
<dependency>
<groupId>com.github.kittinunf.fuel</groupId>
<artifactId>fuel-coroutines</artifactId>
<version>[LATEST_VERSION]</version>
</dependency>

Usage

Coroutines module provides extension functions to wrap a response inside a coroutine and handle its result. The coroutines-based API provides equivalent methods to the standard API (e.g: responseString() in coroutines is awaitStringResponseResult()).

runBlocking {
val (request, response, result) = Fuel.get("https://httpbin.org/ip").awaitStringResponseResult()
result.fold(
{ data -> println(data) /* "{"origin":"127.0.0.1"}" */ },
{ error -> println("An error of type ${error.exception} happened: ${error.message}") }
)
}

There are functions to handle Result object directly too.

runBlocking {
Fuel.get("https://httpbin.org/ip")
.awaitStringResponseResult()
.fold(
{ data -> println(data) /* "{"origin":"127.0.0.1"}" */ },
{ error -> println("An error of type ${error.exception} happened: ${error.message}") }
)
}

It also provides useful methods to retrieve the ByteArray,String or Object directly. The difference with these implementations is that they throw exception instead of returning it wrapped a FuelError instance.

runBlocking {
try {
println(Fuel.get("https://httpbin.org/ip").awaitString()) // "{"origin":"127.0.0.1"}"
} catch(exception: Exception) {
println("A network request exception was thrown: ${exception.message}")
}
}

Handling objects other than String (awaitStringResponseResult()) or ByteArray (awaitByteArrayResponseResult()) can be done using awaitObject, awaitObjectResult or awaitObjectResponseResult.

data class Ip(val origin: String)
object IpDeserializer : ResponseDeserializable<Ip> {
override fun deserialize(content: String) =
jacksonObjectMapper().readValue<Ip>(content)
}
runBlocking {
Fuel.get("https://httpbin.org/ip")
.awaitObjectResult(IpDeserializer)
.fold(
{ data -> println(data.origin) /* 127.0.0.1 */ },
{ error -> println("An error of type ${error.exception} happened: ${error.message}") }
)
}
runBlocking {
try {
val data = Fuel.get("https://httpbin.org/ip").awaitObject(IpDeserializer)
println(data.origin) // 127.0.0.1
} catch (exception: Exception) {
when (exception){
is HttpException -> println("A network request exception was thrown: ${exception.message}")
is JsonMappingException -> println("A serialization/deserialization exception was thrown: ${exception.message}")
else -> println("An exception [${exception.javaClass.simpleName}\"] was thrown")
}
}
}