Enviar solicitação POST com dados JSON usando Volley

Eu gostaria de enviar um novo JsonObjectRequest pedido:

• Quero receber dados JSON (resposta do servidor): OK

• Quero enviar dados formatados em JSON com esta solicitação para o servidor

  JsonObjectRequest request = new JsonObjectRequest(
      Request.Method.POST, "myurl.com", null,
      new Response.Listener<JSONObject>() {
          @Override
          public void onResponse(JSONObject response) {
              //...
          }
      },
      new Response.ErrorListener() {
          @Override
          public void onErrorResponse(VolleyError error) {
              //...
          }
      })
      {
          @Override
          protected Map<String,String> getParams() {
              // something to do here ??
              return params;
          }
  
          @Override
          public Map<String, String> getHeaders() throws AuthFailureError {
              // something to do here ??
              return params;
          }
      };
  

PS Eu uso a biblioteca GSON no meu projeto também.

JsonObjectRequestrealmente aceita JSONObjectcomo corpo.

Deste artigo do blog ,

final String url = "some/url";
final JSONObject jsonBody = new JSONObject("{\"type\":\"example\"}");

new JsonObjectRequest(url, jsonBody, new Response.Listener<JSONObject>() { ... });

Aqui está o código-fonte e JavaDoc ( @param jsonRequest):

/**
 * Creates a new request.
 * @param method the HTTP method to use
 * @param url URL to fetch the JSON from
 * @param jsonRequest A {@link JSONObject} to post with the request. Null is allowed and
 *   indicates no parameters will be posted along with request.
 * @param listener Listener to receive the JSON response
 * @param errorListener Error listener, or null to ignore errors.
 */
public JsonObjectRequest(int method, String url, JSONObject jsonRequest,
        Listener<JSONObject> listener, ErrorListener errorListener) {
    super(method, url, (jsonRequest == null) ? null : jsonRequest.toString(), listener,
                errorListener);
}

Eu sei que este tópico é bastante antigo, mas eu tive esse problema e eu vim com uma solução legal que pode ser muito útil para muitos porque corrige / amplia a biblioteca do Volley em muitos aspectos.

Eu identifiquei alguns recursos não compatíveis do Volley:

• Isso JSONObjectRequestnão é perfeito: você tem que esperar um JSONno final (veja o Response.Listener<JSONObject>).
• E as Respostas vazias (apenas com status 200)?
• O que eu faço se quiser meu POJO diretamente do ResponseListener?

Eu mais ou menos compilei muitas soluções em uma grande classe genérica para ter uma solução para todo o problema que citei.

  /**
  * Created by laurentmeyer on 25/07/15.
  */
 public class GenericRequest<T> extends JsonRequest<T> {

     private final Gson gson = new Gson();
     private final Class<T> clazz;
     private final Map<String, String> headers;
     // Used for request which do not return anything from the server
     private boolean muteRequest = false;

     /**
      * Basically, this is the constructor which is called by the others.
      * It allows you to send an object of type A to the server and expect a JSON representing a object of type B.
      * The problem with the #JsonObjectRequest is that you expect a JSON at the end.
      * We can do better than that, we can directly receive our POJO.
      * That's what this class does.
      *
      * @param method:        HTTP Method
      * @param classtype:     Classtype to parse the JSON coming from the server
      * @param url:           url to be called
      * @param requestBody:   The body being sent
      * @param listener:      Listener of the request
      * @param errorListener: Error handler of the request
      * @param headers:       Added headers
      */
     private GenericRequest(int method, Class<T> classtype, String url, String requestBody,
                           Response.Listener<T> listener, Response.ErrorListener errorListener, Map<String, String> headers) {
         super(method, url, requestBody, listener,
                 errorListener);
         clazz = classtype;
         this.headers = headers;
         configureRequest();
     }

     /**
      * Method to be called if you want to send some objects to your server via body in JSON of the request (with headers and not muted)
      *
      * @param method:        HTTP Method
      * @param url:           URL to be called
      * @param classtype:     Classtype to parse the JSON returned from the server
      * @param toBeSent:      Object which will be transformed in JSON via Gson and sent to the server
      * @param listener:      Listener of the request
      * @param errorListener: Error handler of the request
      * @param headers:       Added headers
      */
     public GenericRequest(int method, String url, Class<T> classtype, Object toBeSent,
                           Response.Listener<T> listener, Response.ErrorListener errorListener, Map<String, String> headers) {
         this(method, classtype, url, new Gson().toJson(toBeSent), listener,
                 errorListener, headers);
     }

     /**
      * Method to be called if you want to send some objects to your server via body in JSON of the request (without header and not muted)
      *
      * @param method:        HTTP Method
      * @param url:           URL to be called
      * @param classtype:     Classtype to parse the JSON returned from the server
      * @param toBeSent:      Object which will be transformed in JSON via Gson and sent to the server
      * @param listener:      Listener of the request
      * @param errorListener: Error handler of the request
      */
     public GenericRequest(int method, String url, Class<T> classtype, Object toBeSent,
                           Response.Listener<T> listener, Response.ErrorListener errorListener) {
         this(method, classtype, url, new Gson().toJson(toBeSent), listener,
                 errorListener, new HashMap<String, String>());
     }

     /**
      * Method to be called if you want to send something to the server but not with a JSON, just with a defined String (without header and not muted)
      *
      * @param method:        HTTP Method
      * @param url:           URL to be called
      * @param classtype:     Classtype to parse the JSON returned from the server
      * @param requestBody:   String to be sent to the server
      * @param listener:      Listener of the request
      * @param errorListener: Error handler of the request
      */
     public GenericRequest(int method, String url, Class<T> classtype, String requestBody,
                           Response.Listener<T> listener, Response.ErrorListener errorListener) {
         this(method, classtype, url, requestBody, listener,
                 errorListener, new HashMap<String, String>());
     }

     /**
      * Method to be called if you want to GET something from the server and receive the POJO directly after the call (no JSON). (Without header)
      *
      * @param url:           URL to be called
      * @param classtype:     Classtype to parse the JSON returned from the server
      * @param listener:      Listener of the request
      * @param errorListener: Error handler of the request
      */
     public GenericRequest(String url, Class<T> classtype, Response.Listener<T> listener, Response.ErrorListener errorListener) {
         this(Request.Method.GET, url, classtype, "", listener, errorListener);
     }

     /**
      * Method to be called if you want to GET something from the server and receive the POJO directly after the call (no JSON). (With headers)
      *
      * @param url:           URL to be called
      * @param classtype:     Classtype to parse the JSON returned from the server
      * @param listener:      Listener of the request
      * @param errorListener: Error handler of the request
      * @param headers:       Added headers
      */
     public GenericRequest(String url, Class<T> classtype, Response.Listener<T> listener, Response.ErrorListener errorListener, Map<String, String> headers) {
         this(Request.Method.GET, classtype, url, "", listener, errorListener, headers);
     }

     /**
      * Method to be called if you want to send some objects to your server via body in JSON of the request (with headers and muted)
      *
      * @param method:        HTTP Method
      * @param url:           URL to be called
      * @param classtype:     Classtype to parse the JSON returned from the server
      * @param toBeSent:      Object which will be transformed in JSON via Gson and sent to the server
      * @param listener:      Listener of the request
      * @param errorListener: Error handler of the request
      * @param headers:       Added headers
      * @param mute:          Muted (put it to true, to make sense)
      */
     public GenericRequest(int method, String url, Class<T> classtype, Object toBeSent,
                           Response.Listener<T> listener, Response.ErrorListener errorListener, Map<String, String> headers, boolean mute) {
         this(method, classtype, url, new Gson().toJson(toBeSent), listener,
                 errorListener, headers);
         this.muteRequest = mute;
     }

     /**
      * Method to be called if you want to send some objects to your server via body in JSON of the request (without header and muted)
      *
      * @param method:        HTTP Method
      * @param url:           URL to be called
      * @param classtype:     Classtype to parse the JSON returned from the server
      * @param toBeSent:      Object which will be transformed in JSON via Gson and sent to the server
      * @param listener:      Listener of the request
      * @param errorListener: Error handler of the request
      * @param mute:          Muted (put it to true, to make sense)
      */
     public GenericRequest(int method, String url, Class<T> classtype, Object toBeSent,
                           Response.Listener<T> listener, Response.ErrorListener errorListener, boolean mute) {
         this(method, classtype, url, new Gson().toJson(toBeSent), listener,
                 errorListener, new HashMap<String, String>());
         this.muteRequest = mute;

     }

     /**
      * Method to be called if you want to send something to the server but not with a JSON, just with a defined String (without header and not muted)
      *
      * @param method:        HTTP Method
      * @param url:           URL to be called
      * @param classtype:     Classtype to parse the JSON returned from the server
      * @param requestBody:   String to be sent to the server
      * @param listener:      Listener of the request
      * @param errorListener: Error handler of the request
      * @param mute:          Muted (put it to true, to make sense)
      */
     public GenericRequest(int method, String url, Class<T> classtype, String requestBody,
                           Response.Listener<T> listener, Response.ErrorListener errorListener, boolean mute) {
         this(method, classtype, url, requestBody, listener,
                 errorListener, new HashMap<String, String>());
         this.muteRequest = mute;

     }


     @Override
     protected Response<T> parseNetworkResponse(NetworkResponse response) {
         // The magic of the mute request happens here
         if (muteRequest) {
             if (response.statusCode >= 200 && response.statusCode <= 299) {
                 // If the status is correct, we return a success but with a null object, because the server didn't return anything
                 return Response.success(null, HttpHeaderParser.parseCacheHeaders(response));
             }
         } else {
             try {
                 // If it's not muted; we just need to create our POJO from the returned JSON and handle correctly the errors
                 String json = new String(response.data, HttpHeaderParser.parseCharset(response.headers));
                 T parsedObject = gson.fromJson(json, clazz);
                 return Response.success(parsedObject, HttpHeaderParser.parseCacheHeaders(response));
             } catch (UnsupportedEncodingException e) {
                 return Response.error(new ParseError(e));
             } catch (JsonSyntaxException e) {
                 return Response.error(new ParseError(e));
             }
         }
         return null;
     }

     @Override
     public Map<String, String> getHeaders() throws AuthFailureError {
         return headers != null ? headers : super.getHeaders();
     }

     private void configureRequest() {
         // Set retry policy
         // Add headers, for auth for example
         // ...
     }
 }

Pode parecer um pouco exagerado, mas é muito legal ter todos esses construtores porque você tem todos os casos:

(O construtor principal não foi feito para ser usado diretamente, embora seja, obviamente, possível).

1. Solicitação com resposta analisada para POJO / Cabeçalhos definidos manualmente / POJO para enviar
2. Solicitação com resposta analisada para POJO / POJO para enviar
3. Solicitação com resposta analisada para POJO / String a ser enviada
4. Solicitação com resposta analisada para POJO (GET)
5. Solicitação com resposta analisada para POJO (GET) / Cabeçalhos definidos manualmente
6. Solicitação sem resposta (200 - Corpo vazio) / Cabeçalhos definidos manualmente / POJO para enviar
7. Solicitação sem resposta (200 - Corpo vazio) / POJO para enviar
8. Solicitação sem resposta (200 - Corpo vazio) / String a enviar

Claro, para que funcione, você precisa ter o GSON Lib do Google; basta adicionar:

compile 'com.google.code.gson:gson:x.y.z'

às suas dependências (a versão atual é 2.3.1).

final String URL = "/volley/resource/12";
// Post params to be sent to the server
HashMap<String, String> params = new HashMap<String, String>();
params.put("token", "AbCdEfGh123456");

JsonObjectRequest req = new JsonObjectRequest(URL, new JSONObject(params),
       new Response.Listener<JSONObject>() {
           @Override
           public void onResponse(JSONObject response) {
               try {
                   VolleyLog.v("Response:%n %s", response.toString(4));
               } catch (JSONException e) {
                   e.printStackTrace();
               }
           }
       }, new Response.ErrorListener() {
           @Override
           public void onErrorResponse(VolleyError error) {
               VolleyLog.e("Error: ", error.getMessage());
           }
       });

// add the request object to the queue to be executed
ApplicationController.getInstance().addToRequestQueue(req);

referir

• Crie um objeto de RequestQueueclasse.

  RequestQueue queue = Volley.newRequestQueue(this);
  

• Crie um StringRequestlistener com resposta e erro.

   StringRequest sr = new StringRequest(Request.Method.POST,"http://api.someservice.com/post/comment", new Response.Listener<String>() {
      @Override
      public void onResponse(String response) {
          mPostCommentResponse.requestCompleted();
      }
  }, new Response.ErrorListener() {
      @Override
      public void onErrorResponse(VolleyError error) {
          mPostCommentResponse.requestEndedWithError(error);
      }
  }){
      @Override
      protected Map<String,String> getParams(){
          Map<String,String> params = new HashMap<String, String>();
          params.put("user",userAccount.getUsername());
          params.put("pass",userAccount.getPassword());
          params.put("comment", Uri.encode(comment));
          params.put("comment_post_ID",String.valueOf(postId));
          params.put("blogId",String.valueOf(blogId));
  
          return params;
      }
  
      @Override
      public Map<String, String> getHeaders() throws AuthFailureError {
          Map<String,String> params = new HashMap<String, String>();
          params.put("Content-Type","application/x-www-form-urlencoded");
          return params;
      }
  };
  

• Adicione sua solicitação ao RequestQueue.

  queue.add(jsObjRequest);
  

• Crie uma PostCommentResponseListenerinterface apenas para que você possa vê-la. É um delegado simples para a solicitação assíncrona.

  public interface PostCommentResponseListener {
  public void requestStarted();
  public void requestCompleted();
  public void requestEndedWithError(VolleyError error);
  }
  

• Inclui permissão de INTERNET dentro do AndroidManifest.xmlarquivo.

  <uses-permission android:name="android.permission.INTERNET"/>
  

    final String url = "some/url";

ao invés de:

    final JSONObject jsonBody = "{\"type\":\"example\"}";

você pode usar:

  JSONObject jsonBody = new JSONObject();
    try {
        jsonBody.put("type", "my type");
    } catch (JSONException e) {
        e.printStackTrace();
    }
new JsonObjectRequest(url, jsonBody, new Response.Listener<JSONObject>() { ... });

final Map<String,String> params = new HashMap<String,String>();
        params.put("email", customer.getEmail());
        params.put("password", customer.getPassword());
        String url = Constants.BASE_URL+"login";

doWebRequestPost(url, params);


public void doWebRequestPost(String url, final Map<String,String> json){
        getmDialogListener().showDialog();

    StringRequest post = new StringRequest(Request.Method.POST, url, new Response.Listener<String>() {
        @Override
        public void onResponse(String response) {
            try {
                getmDialogListener().dismissDialog();
                response....

            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            Log.d(App.TAG,error.toString());
            getmDialogListener().dismissDialog();

        }
    }){
        @Override
        protected Map<String, String> getParams() throws AuthFailureError {
            Map<String,String> map = json;

            return map;
        }
    };
    App.getInstance().getRequestQueue().add(post);

}

Você também pode enviar dados substituindo o getBody()método da JsonObjectRequestclasse. Como mostrado abaixo.

    @Override
    public byte[] getBody()
    {

        JSONObject jsonObject = new JSONObject();
        String body = null;
        try
        {
            jsonObject.put("username", "user123");
            jsonObject.put("password", "Pass123");

            body = jsonObject.toString();
        } catch (JSONException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        try
        {
            return body.toString().getBytes("utf-8");
        } catch (UnsupportedEncodingException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return null;
    }

protected Map<String, String> getParams() {
   Map<String, String> params = new HashMap<String, String>();

   JSONObject JObj = new JSONObject();

   try {
           JObj.put("Id","1");
           JObj.put("Name", "abc");

   } catch (Exception e) {
       e.printStackTrace();
   }

   params.put("params", JObj.toString());
   // Map.Entry<String,String>
   Log.d("Parameter", params.toString());
   return params;
}