public class App {
    public static void main(String[] args) throws Exception {
        ResteasyClient client = new ResteasyClientBuilder().register(CustomResponseFilter.class).build();
        Response response = client.target("http://google.com").request().get();
        System.out.println(response.readEntity(String.class));
        System.out.println(response.getStatus());
    }
}
public class CustomResponseFilter implements ClientResponseFilter {
    public void filter(ClientRequestContext requestContext, ClientResponseContext responseContext) throws IOException {
        Response response = Response.ok(responseContext.getEntityStream()).build();
        if (responseContext.getStatus() == 301) {
            ResponseChecker301.check(response);
        }
//      if (responseContext.getStatus() == 500) {
//          ResponseChecker500.check(response);
//      }
//      ...
    }
}
public class ResponseChecker301 {
    public static void check(Response response) {
        String responseContent = response.readEntity(String.class);
        if (responseContent.contains("Error")) {
            throw new RuntimeException(responseContent);
        }
    }
}