title: Rerofit2 post error when I send DTO by FormUrlEncoded
body: <p>I occur error as '@Body parameters cannot be used with form or multi-part encoding' When I send the DTO by FormUrlEncoded
  naturally when I remove the @FormUrlEncoded than it doesn't occur error
  But My server construct for FormUrlEncoded </p>
  
  <p>So I want to send the DTO by FormUrlEncoded, What should I do?</p>
  
  <p>RestAPI.java</p>
  
  <pre><code>public interface RestAPI {
      interface Join {
          @FormUrlEncoded
          @POST("/api/users")
          Call&lt;Res&gt; createTask(@Body User user);
      }
      Retrofit RETROFIT = new Retrofit.Builder().baseUrl(Config.ServerUrl).addConverterFactory(GsonConverterFactory.create()).build();
  }
  
  
  public class User {
  String username;
  String password;
  
  
  public String getUsername() {
      return username;
  }
  
  public void setUsername(String username) {
      this.username = username;
  }
  
  public String getPassword() {
      return password;
  }
  
  public void setPassword(String password) {
      this.password = password;
  }
  }
  </code></pre>
  
  <p>Res.java</p>
  
  <pre><code>public class Res {
  
  private Boolean response;
  private String msg;
  
  public Boolean getResponse() {
      return response;
  }
  
  public void setResponse(Boolean response) {
      this.response = response;
  }
  
  public String getMsg() {
      return msg;
  }
  
  public void setMsg(String msg) {
      this.msg = msg;
  }
  }
  </code></pre>
  
  <p>Main.java</p>
  
  <pre><code>user = new User();
  user.setUsername("TEST");
  user.setPassword("1234");
      RestAPI.Join join = RestAPI.RETROFIT.create(RestAPI.Join.class);
      Call&lt;Res&gt; resCall = join.createTask(user);
      resCall.enqueue(new Callback&lt;Res&gt;() {
      @Override
      public void onResponse(Call&lt;Res&gt; call, Response&lt;Res&gt; response) {
      System.out.println(response.body().getResponse());
      }
  
      @Override
      public void onFailure(Call&lt;Res&gt; call, Throwable t) {
  
      }
      });
  </code></pre>