Horizon

Java HTTP client interfaces designed to make interacting with REST services as user-friendly as possible. Horizon classes use intuitive, fluent APIs and leverage Jackson internally so that reading and writing JSON are first-class citizens.

Features

• Clean, simple interfaces
• Designed to work with JSON
• GZIP and Snappy support for compression/decompression
• Built-in retry functionality with exponential backoff
• Free to mix and match synchronous and asynchronous clients

Usage

The HorizonCore module contains all of the interfaces and domain objects. Horizon comes with two implementations, packaged in separate artifacts. The HorizonApache module contains an implementation of the synchronous HttpClient interface, built on top of Apache's httpclient 4. The HorizonNing module contains an implementation of both HttpClient and AsyncHttpClient built on top of org.asynchttpclient.shaded:async-http-client. So if you just want to use the Apache-based client, you would add the following Maven dependency:

<dependency>
  <groupId>com.hubspot</groupId>
  <artifactId>HorizonApache</artifactId>
  <version>0.2.0</version>
</dependency>

And then you can instantiate a new HttpClient by doing HttpClient httpClient = new ApacheHttpClient();

Examples

Using the synchronous HttpClient to retrieve a single Widget by ID:

public Widget getById(int id) {
    HttpRequest request = HttpRequest.newBuilder().setUrl("http://widgets/" + id).build();
    // Jackson is used to convert JSON response to Widget object
    return httpClient.execute(request).getAs(Widget.class);
}

Updating a widget:

public Widget update(Widget widget) {
    HttpRequest request = HttpRequest.newBuilder()
            .setMethod(Method.PUT)
            .setUrl("http://widgets/" + widget.getId())
            .setBody(widget) // Jackson is used to convert Widget to JSON
            .build();
    
    return httpClient.execute(request).getAs(Widget.class);
}