<!-- Pull in as a traditional dependency -->
<dependency>
    <groupId>com.konghq</groupId>
    <artifactId>unirest-java</artifactId>
    <version>2.3.07</version>
</dependency>

<!-- OR as a snazzy new standalone jar with shaded dependencies -->
<dependency>
    <groupId>com.konghq</groupId>
    <artifactId>unirest-java</artifactId>
    <version>2.3.07</version>
    <classifier>standalone</classifier>
</dependency>

See the Upgrade Guide

See the Change Log for recent changes.

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> response = Unirest.post("http://httpbin.org/post")
      .header("accept", "application/json")
      .queryString("apiKey", "123")
      .field("parameter", "value")
      .field("foo", "bar")
      .asString();

Requests are made when as[Type]() is invoked, possible types include Json, String, Object Empty and File.

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/{fruit}")
     .routeParam("fruit", "apple")
     .asString();

// Results in `http://httpbin.org/apple`

Basically the placeholder {method} will be replaced with apple.

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

All param values will be URL-Encoded for you

Query-string params can be built up one by one

Unirest.get("http://httpbin.org")
                .queryString("fruit", "apple")
                .queryString("droid", "R2D2")
                .asString();

// Results in "http://httpbin.org?fruit=apple&droid=R2D2"

Again all param values will be URL-Encoded.

You can also pass in query strings as arrays and maps:

Unirest.get("http://httpbin.org")
        .queryString("fruit", Arrays.asList("apple", "orange"))
        .queryString(ImmutableMap.of("droid", "R2D2", "beatle", "Ringo"))
        .asString();

 // Results in "http://httpbin.org?fruit=apple&fruit=orange&droid=R2D2&beatle=Ringo"

Request headers can be added with the header method.

Unirest.get("http://httpbin.org")
            .header("Accept", "application/json")
            .header("x-custom-header", "hello")
            .asString();

Unirest exposes a shortcut for doing basic auth when you need to. Unirest handles the Base64 encoding part. Please make sure you are always doing this over HTTPS!

Unirest.get("http://httpbin.org")
            .basicAuth("user", "password1!")
            .asString();

// this adds the header "Authorization: Basic dXNlcjpwYXNzd29yZDEh"

You can post entity objects as the full body easily. This is the default behavior of most REST services.

Unless you specify otherwise the default Content-Type is text/plain; charset=UTF-8

Unirest.post("http://httpbin.org")
                .body("This is the entire body")
                .asEmpty();

You can also post as a Object that is serialized using a configured ObjectMapper. (see Object Mappers for implementation details.

// Object Mappers can be configured globally, per config, or on a per-request basis.
// We will set it up in the global config here:

Unirest.config().setObjectMapper(new JacksonObjectMapper());

Unirest.post("http://httpbin.org")
            .header("Content-Type", "application/json")
            .body(new SomeUserObject("Bob"))
            .asEmpty();

// This will use Jackson to serialize the object into JSON.

Unirest has full native support for JSON Patch requests (RFC-6902 see http://jsonpatch.com/) Per the spec, the default Content-Type for json-patch is application/json-patch+json

     Unirest.jsonPatch("http://httpbin.org")
            .add("/fruits/-", "Apple")
            .remove("/bugs")
            .replace("/lastname", "Flintstone")
            .test("/firstname", "Fred")
            .move("/old/location", "/new/location")
            .copy("/original/location", "/new/location")
            .asJson();

will send a request with a body of

  [
     {"op":"add","path":"/fruits/-","value":"Apple"},
     {"op":"remove","path":"/bugs"},
     {"op":"replace","path":"/lastname","value":"Flintstone"},
     {"op":"test","path":"/firstname","value":"Fred"},
     {"op":"move","path":"/new/location","from":"/old/location"},
     {"op":"copy","path":"/new/location","from":"/original/location"}
  ]

Basic http name value body params can be passed with simple field calls. The Content-Type for this type of request is defaulted to application/x-www-form-urlencoded

Unirest.post("http://httpbin.org")
       .field("fruit", "apple")
       .field("droid", "R2D2")
       .asEmpty();

  // This will post a simple name-value pair body the same as a HTML form. This looks like
  // `fruit=apple&droid=R2D2'

You can also post binary data in a form. Like a file.

The Content-Type for this type of request is defaulted to multipart/form-data

Unirest.post("http://httpbin.org")
       .field("upload", new File("/MyFile.zip"))
       .asEmpty();

For large files you may want to use a InputStream. Pass it a file name if you want one. We are using a FileInputStream here but it can actually be any kind of InputStream.

InputStream file = new FileInputStream(new File("/MyFile.zip"));

Unirest.post("http://httpbin.org")
       .field("upload", file, "MyFile.zip")
       .asEmpty();

If you are uploading large files you might want to provide some time of progress bar to a user. You can monitor this progress by providing a ProgresMonitor.

          Unirest.post("http://httpbin.org")
                .field("upload", new File("/MyFile.zip"))
                .uploadMonitor((field, fileName, bytesWritten, totalBytes) -> {
                    updateProgressBarWithBytesLeft(totalBytes - bytesWritten);
                })
                .asEmpty();

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. All request types also support async versions.

CompletableFuture<HttpResponse<JsonNode>> future = Unirest.post("http://httpbin.org/post")
  .header("accept", "application/json")
  .field("param1", "value1")
  .field("param2", "value2")
  .asJsonAsync(response -> {
        int code = response.getStatus();
        JsonNode body = response.getBody();
    });

Sometimes services offer paged requests. How this is done is not standardized but Unirest proves a mechanism to follow pages until all have been consumed. You must provide two functions for extracting the next page. The first is to get the HttpResponse in the format you want, the other is to extract the next link from the response. The result is a PagedList of HttpResponse<T>. The paged list has some handy methods for dealing with the results. Here we are getting a paged list of Dogs where the next link is in the headers.

PagedList<Doggos> result =  Unirest.get("https://somewhere/dogs")
                .asPaged(
                        r -> r.asObject(Doggos.class),
                        r -> r.getHeaders().getFirst("nextPage")
                );
                

Unirest makes the actual request the moment you invoke of it's as[type] method. These methods also inform Unirest what type to map the response to. Options are Empty, String, File, Object, and Json.

The response returns as a HttpResponse<T> where the HttpResponse object has all of the common response data like status and headers. The Body (if present) can be accessed via the desired type with the .body() method.

If you aren't expecting a body back, asEmpty is the easiest choice. You will still get back response information like status and headers.

HttpResponse response = Unirest.delete("http://httpbin.org").asEmpty()

The next easiest response type is String. You can do whatever you want with it after that.

String body = Unirest.get("http://httpbin.org")
					 .asString()
					 .body();

Most of the time when consuming RESTful services you probably want to map the response into an object. For this you need to provide the Unirest configuration with a implementation of ObjectMapper (see Object Mappers for details.). Unirest has several modules that can be included for popular JSON object mappers like Jackson and GSON.

Before an asObject(Class) it is necessary to provide a custom implementation of the ObjectMapper interface. This should be done only the first time, as the instance of the ObjectMapper will be shared globally.

Unirest offers a few plug-ins implementing popular object mappers like Jackson and Gson. See mvn central for details.

For example, serializing Json from\to Object using the popular Jackson ObjectMapper takes only few lines

// Only one time
Unirest.config().setObjectMapper(new JacksonObjectMapper());

// Response to Object
Book book = Unirest.get("http://httpbin.org/books/1")
                   .asObject(Book.class)
                   .getBody();

Author author = Unirest.get("http://httpbin.org/books/{id}/author")
                       .routeParam("id", bookObject.getId())
                       .asObject(Author.class)
                       .getBody();

You can't always get what you want. And sometimes results you get from web services will not map into what you expect them to. When this happens with a asObject or asJson request the resulting body will be null, but the response object will contain a ParsingException that allows you to get the error and the original body for inspection.

UnirestParsingException ex = response.getParsingError().get();

ex.getOriginalBody(); // Has the original body as a string.
ex.getMessage(); // Will have the parsing exception.
ex.getCause(); // of course will have the original parsing exception itself.

Sometimes you just want to download a file, or maybe capture the response body into a file. Unirest can do both. Just tell Unirest where you want to put the file.

File result = Unirest.get("http://some.file.location/file.zip")
                .asFile("/disk/location/file.zip")
                .getBody();

Unirest offers a lightweight JSON response type when you don't need a full Object Mapper.

String result = Unirest.get("http://some.json.com")
				       .getBody()
				       .getObject()
				       .getJSONObject("thing")
				       .getJSONArray("foo")
				       .get(0)

Some response methods (asString, asJson) read the entire response stream into memory. In order to read the original stream and handle large responses you can use several functional methods like:

   Map r = Unirest.get(MockServer.GET)
                .queryString("foo", "bar")
                .asObject(i -> new Gson().fromJson(i.getContentReader(), HashMap.class))
                .getBody();

or consumers:

         Unirest.get(MockServer.GET)
                .thenConsumeAsync(r -> {
                       // something like writing a file to disk
                });

the HttpResponse object has a few handler methods that can be chained to deal with success and failure:

• ifSuccess(Consumer<HttpResponse<T>> response) will be called if the response was a 200-series response and any body processing (like json or Object was successful.
• ifFailure(Consumer<HttpResponse> response will be called if the status was 400+ or body processing failed.

Putting them together might look like this:

         Unirest.get("http://somewhere")
                .asJson()
                .ifSuccess(response -> someSuccessMethod(response))
                .ifFailure(response -> {
                    log.error("Oh No! Status" + response.getStatus());
                    response.getParsingError().ifPresent(e -> {
                        log.error("Parsing Exception: ", e);
                        log.error("Original body: " + e.getOriginalBody());
                    });
                });

Previous versions of unirest had configuration split across several different places. Sometimes it was done on Unirest, sometimes it was done on Option, sometimes it was somewhere else. All configuration is now done through Unirest.config()

    Unirest.config()
           .socketTimeout(500)
           .connectTimeout(1000)
           .concurrency(10, 5)
           .proxy(new Proxy("https://proxy"))
           .setDefaultHeader("Accept", "application/json")
           .followRedirects(false)
           .enableCookieManagement(false)
           .addInterceptor(new MyCustomInterceptor());

Changing Unirest's config should ideally be done once, or rarely. There are several background threads spawned by both Unirest itself and Apache HttpAsyncClient. Once Unirest has been activated configuration options that are involved in creating the client cannot be changed without an explicit shutdown or reset.

You can set your own custom Apache HttpClient and HttpAsyncClient. Note that Unirest settings like timeouts or interceptors are not applied to custom clients.

     Unirest.config()
            .httpClient(myClient)
            .asyncClient(myAsyncClient)

As usual, Unirest maintains a primary single instance. Sometimes you might want different configurations for different systems. You might also want an instance rather than a static context for testing purposes.

    // this returns the same instance used by Unirest.get("http://somewhere/")
    UnirestInstance unirest = Unirest.primaryInstance();
    // It can be configured and used just like the static context
    unirest.config().connectTimeout(5000);
    String result = unirest.get("http://foo").asString().getBody();

    // You can also get a whole new instance
    UnirestInstance unirest = Unirest.spawnInstance();

WARNING! If you get a new instance of unirest YOU are responsible for shutting it down when the JVM shuts down. It is not tracked or shut down by Unirest.shutDown();

Unirest offers a few different Object Mapper's based on popular JSON libraries (Jackson and GSON). These can be included either as traditional or shaded jars:

<!-- https://mvnrepository.com/artifact/com.konghq/unirest-objectmapper-jackson -->
<dependency>
    <groupId>com.konghq</groupId>
    <artifactId>unirest-objectmapper-jackson</artifactId>
    <version>2.3.07</version>
</dependency>


<!-- https://mvnrepository.com/artifact/com.konghq/unirest-object-mappers-gson -->
<dependency>
    <groupId>com.konghq</groupId>
    <artifactId>unirest-object-mappers-gson</artifactId>
    <version>2.3.07</version>
</dependency>

If you have some other need you can supply your own Object mapper by implementing the ObjectMapper interface. It has only a few methods

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();

Once shutdown, using Unirest again will re-init the system