Unirest for Java

Unirest is a set of lightweight HTTP libraries available in multiple languages, ideal for most applications:

• Make GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS requests
• Both syncronous and asynchronous (non-blocking) requests
• It supports form parameters, file uploads and custom body entities
• Easily add route parameters without ugly string concatenations
• Supports gzip
• Supports Basic Authentication natively
• Customizable timeout
• Customizable default headers for every request (DRY)
• Customizable HttpClient and HttpAsyncClient implementation
• Automatic JSON parsing into a native object for JSON responses

Created with love by thefosk @ mashape.com

Installing

Is easy as pie. Kidding. It's about as easy as doing these little steps:

With Maven

You can use Maven by including the library:

<dependency>
    <groupId>com.mashape.unirest</groupId>
    <artifactId>unirest-java</artifactId>
    <version>1.3.21</version>
</dependency>

There are dependencies for Unirest-Java, these should be already installed, and they are as follows:

<dependency>
  <groupId>org.apache.httpcomponents</groupId>
  <artifactId>httpclient</artifactId>
  <version>4.3.4</version>
</dependency>
<dependency>
  <groupId>org.apache.httpcomponents</groupId>
  <artifactId>httpasyncclient</artifactId>
  <version>4.0.1</version>
</dependency>
<dependency>
  <groupId>org.apache.httpcomponents</groupId>
  <artifactId>httpmime</artifactId>
  <version>4.3.4</version>
</dependency>
<dependency>
  <groupId>org.json</groupId>
  <artifactId>json</artifactId>
  <version>20140107</version>
</dependency>

Without Maven

Alternatively if you don't use Maven, you can directly include the JAR file in the classpath: http://oss.sonatype.org/content/repositories/releases/com/mashape/unirest/unirest-java/1.3.21/unirest-java-1.3.21.jar

Don't forget to also install the dependencies (org.json, httpclient 4.3.4, httpmime 4.3.4, httpasyncclient 4.0.1) in the classpath too.

There is also a way to generate a Unirest-Java JAR file that already includes the required dependencies, but you will need Maven to generate it. Follow the instructions at http://blog.mashape.com/post/69117323931/installing-unirest-java-with-the-maven-assembly-plugin

Creating Request

So you're probably wondering how using Unirest makes creating requests in Java easier, here is a basic POST request that will explain everything:

HttpResponse<JsonNode> jsonResponse = Unirest.post("http://httpbin.org/post")
  .header("accept", "application/json")
  .field("parameter", "value")
  .field("foo", "bar")
  .asJson();

Requests are made when as[Type]() is invoked, possible types include Json, Binary, String. If the request supports and it is of type HttpRequestWithBody, a body it can be passed along with .body(String|JsonNode). If you already have a map of parameters or do not wish to use seperate field methods for each one there is a .fields(Map<String, Object> fields) method that will serialize each key - value to form parameters on your request.

.headers(Map<String, String> headers) is also supported in replacement of multiple header methods.

Route Parameters

Sometimes you want to add dynamic parameters in the URL, you can easily do that by adding a placeholder in the URL, and then by setting the route parameters with the routeParam function, like:

Unirest.get("http://httpbin.org/{method}")
  .routeParam("method", "get")
  .field("name", "Mark")
  .asJson();

In the example above the final URL will be http://httpbin.org/get - Basically the placeholder {method} will be replaced with get.

The placeholder's format is as easy as: {custom_name}

Asynchronous Requests

Sometimes, well most of the time, you want your application to be asynchronous and not block, Unirest supports this in Java using anonymous callbacks, or direct method placement:

Future<HttpResponse<JsonNode>> future = Unirest.post("http://httpbin.org/post")
  .header("accept", "application/json")
  .field("param1", "value1")
  .field("param2", "value2")
  .asJsonAsync(new Callback<JsonNode>() {
	  
	public void failed(UnirestException e) {
		System.out.println("The request has failed");
	}
	
	public void completed(HttpResponse<JsonNode> response) {
		 int code = response.getCode();
	     Map<String, String> headers = response.getHeaders();
	     JsonNode body = response.getBody();
	     InputStream rawBody = response.getRawBody();
	}
	
	public void cancelled() {
		System.out.println("The request has been cancelled");
	}
	
});

File Uploads

Creating multipart requests with Java is trivial, simply pass along a File Object as a field:

HttpResponse<JsonNode> jsonResponse = Unirest.post("http://httpbin.org/post")
  .header("accept", "application/json")
  .field("parameter", "value")
  .field("file", new File("/tmp/file"))
  .asJson();

Custom Entity Body

HttpResponse<JsonNode> jsonResponse = Unirest.post("http://httpbin.org/post")
  .header("accept", "application/json")
  .body("{\"parameter\":\"value\", \"foo\":\"bar\"}")
  .asJson();

Basic Authentication

Authenticating the request with basic authentication can be done by calling the basicAuth(username, password) function:

HttpResponse<JsonNode> response = Unirest.get("http://httpbin.org/headers").basicAuth("username", "password").asJson();

Request

The Java Unirest library follows the builder style conventions. You start building your request by creating a HttpRequest object using one of the following:

GetRequest request = Unirest.get(String url);
GetRequest request = Unirest.head(String url);
HttpRequestWithBody request = Unirest.post(String url);
HttpRequestWithBody request = Unirest.put(String url);
HttpRequestWithBody request = Unirest.patch(String url);
HttpRequestWithBody request = Unirest.options(String url);
HttpRequestWithBody request = Unirest.delete(String url);

Response

Upon recieving a response Unirest returns the result in the form of an Object, this object should always have the same keys for each language regarding to the response details.

• .getCode() - HTTP Response Status Code (Example 200)
• .getHeaders() - HTTP Response Headers
• .getBody() - Parsed response body where applicable, for example JSON responses are parsed to Objects / Associative Arrays.
• .getRawBody() - Un-parsed response body

Advanced Configuration

You can set some advanced configuration to tune Unirest-Java:

Custom HTTP clients

You can explicitly set your own HttpClient and HttpAsyncClient implementations by using the following methods:

Unirest.setHttpClient(httpClient);
Unirest.setAsyncHttpClient(asyncHttpClient);

Timeouts

You can set custom connection and socket timeout values (in milliseconds):

Unirest.setTimeouts(long connectionTimeout, long socketTimeout);

By default the connection timeout is 10000, and the socket timeout is 60000.

Default Request Headers

You can set default headers that will be sent on every request:

Unirest.setDefaultHeader("Header1", "Value1");
Unirest.setDefaultHeader("Header2", "Value2");

You can clear the default headers anytime with:

Unirest.clearDefaultHeaders();

Exiting an application

Unirest starts a background event loop and your Java application won't be able to exit until you manually shutdown all the threads by invoking:

Unirest.shutdown();