JarCastingUnirest for Java 
Unirest is a set of lightweight HTTP libraries available in multiple languages.
Do yourself a favor, and start making HTTP requests like this:
Unirest.post("http://httpbin.org/post")
.queryString("name", "Mark")
.field("last", "Polo")
.asJson()
Features
- Make
GET,POST,PUT,PATCH,DELETE,HEAD,OPTIONSrequests - 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, concurrency levels and proxy settings
- Customizable default headers for every request (DRY)
- Customizable
HttpClientandHttpAsyncClientimplementation - Automatic JSON parsing into a native object for JSON responses
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>1.4.5</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>4.3.6</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpasyncclient</artifactId>
<version>4.0.2</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpmime</artifactId>
<version>4.3.6</version>
</dependency>
<dependency>
<groupId>org.json</groupId>
<artifactId>json</artifactId>
<version>20140107</version>
</dependency>
If you would like to run tests, also add the following dependency along with the others:
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<scope>test</scope>
</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/1.4.5/unirest-java-1.4.5.jar
Don't forget to also install the dependencies (org.json, httpclient 4.3.6, httpmime 4.3.6, httpasyncclient 4.0.2) 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")
.queryString("apiKey", "123")
.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")
.queryString("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.getStatus();
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.
.getStatus()- HTTP Response Status Code (Example: 200).getStatusTest()- HTTP Response Status Text (Example: "OK").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 (the time it takes to connect to a server) is 10000, and the socket timeout (the time it takes to receive data) is 60000. You can set any of these timeouts to zero to disable the timeout.
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();
Concurrency
You can set custom concurrency levels if you need to tune the performance of the syncronous or asyncronous client:
Unirest.setConcurrency(int maxTotal, int maxPerRoute);
By default the maxTotal (overall connection limit in the pool) is 200, and the maxPerRoute (connection limit per target host) is 20.
Proxy
You can set a proxy by invoking:
Unirest.setProxy(new HttpHost("127.0.0.1", 8000));
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();
Made with