Debug Retrofit REST applications

Today I had some problems with designing a Retrofit REST application, so I needed a way to debug the request and the response from the server. After poking around, I found the HttpLoggingInterceptor from OkHttp.  It provides all the functionality I need and is really easy to implement.

First you have create a OkHttpClient instance, add the interceptor and set the debug level to HttpLoggingInterceptor.Level.BODY:

OkHttpClient client = new OkHttpClient();
HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor();
interceptor.setLevel(HttpLoggingInterceptor.Level.BODY);
client.interceptors().add(interceptor);    

Next step is to add the client during the building of the Retrofit instance:

Retrofit retrofit = new Retrofit.Builder().client(client).build();

Now you can see the HTTP data sent over the wire:

Don’t forget to add the two required dependencies to your pom.xml:

<dependency>
   <groupId>com.squareup.okhttp</groupId>
   <artifactId>okhttp</artifactId>
   <version>2.6.0</version>
</dependency>
<dependency>
   <groupId>com.squareup.okhttp</groupId>
   <artifactId>logging-interceptor</artifactId>
   <version>2.6.0</version>
</dependency>