How do you create a REST client for Java? [closed]

Answer 1

You can also check Restlet which has full client-side capabilities, more REST oriented that lower-level libraries such as HttpURLConnection or Apache HTTP Client (which we can leverage as connectors).

Best regards, Jerome Louvel

Answer 2

You could try Rapa. Let us know your feedback about the same. And feel free to log issues or expected features.

Answer 3

OkHttp is lightweight and powerful when combined with Retrofit as well. This works well for general Java use as well as on Android.

OkHttp: http://square.github.io/okhttp/

public static final MediaType JSON
    = MediaType.parse("application/json; charset=utf-8");

OkHttpClient client = new OkHttpClient();

String post(String url, String json) throws IOException {
  RequestBody body = RequestBody.create(JSON, json);
  Request request = new Request.Builder()
      .url(url)
      .post(body)
      .build();
  Response response = client.newCall(request).execute();
  return response.body().string();
}

Retrofit: http://square.github.io/retrofit/

public interface GitHubService {
  @GET("/users/{user}/repos")
  Call<List<Repo>> listRepos(@Path("user") String user);
}

Answer 4

I wrote a library that maps a java interface to a remote JSON REST service:

https://github.com/ggeorgovassilis/spring-rest-invoker

public interface BookService {
   @RequestMapping("/volumes")
   QueryResult findBooksByTitle(@RequestParam("q") String q);

   @RequestMapping("/volumes/{id}")
   Item findBookById(@PathVariable("id") String id);
}

Answer 5

Try looking at http-rest-client

https://github.com/g00dnatur3/http-rest-client

Here is a simple example:

RestClient client = RestClient.builder().build();
String geocoderUrl = "http://maps.googleapis.com/maps/api/geocode/json"
Map<String, String> params = Maps.newHashMap();
params.put("address", "beverly hills 90210");
params.put("sensor", "false");
JsonNode node = client.get(geocoderUrl, params, JsonNode.class);

The library takes care of json serialization and binding for you.

Here is another example,

RestClient client = RestClient.builder().build();
String url = ...
Person person = ...
Header header = client.create(url, person);
if (header != null) System.out.println("Location header is:" + header.value());

And one last example,

RestClient client = RestClient.builder().build();
String url = ...
Person person = client.get(url, null, Person.class); //no queryParams

Cheers!

Answer 6

If you only wish to invoke a REST service and parse the response you can try out Rest Assured

// Make a GET request to "/lotto"
String json = get("/lotto").asString()
// Parse the JSON response
List<String> winnderIds = with(json).get("lotto.winners.winnerId");

// Make a POST request to "/shopping"
String xml = post("/shopping").andReturn().body().asString()
// Parse the XML
Node category = with(xml).get("shopping.category[0]");