使用Volley发送带有JSON数据的POST请求

Question

我想发一个新JsonObjectRequest请求:

• 我想接收JSON数据(来自服务器的响应):好的

• 我想将带有此请求的JSON格式数据发送到服务器

  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我也在我的项目中使用GSON库.

Answer 1

JsonObjectRequest实际上接受JSONObject为身体.

从这篇博客文章中,

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

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

这是源代码和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);
}

Answer 2

我知道这个线程已经很老了,但是我遇到了这个问题,我提出了一个很酷的解决方案,对许多人来说非常有用,因为它在许多方面纠正/扩展了Volley库.

我发现了一些不支持开箱即用的Volley功能:

• 这JSONObjectRequest并不完美:你必须期待JSON最后(见Response.Listener<JSONObject>).
• 空响应怎么样(只有200状态)？
• 如果我直接想要我的POJO怎么办ResponseListener？

我或多或少在一个大的泛型类中编译了很多解决方案,以便为我引用的所有问题找到解决方案.

  /**
  * 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
         // ...
     }
 }

这看起来有点矫枉过正,但拥有所有这些构造函数非常酷,因为你有所有的情况:

(主要构造函数不应该直接使用,当然,这是可能的).

1. 请求响应解析为POJO/Headers手动设置/ POJO发送
2. 请求响应解析为POJO/POJO发送
3. 请求响应解析为POJO/String to Send
4. 请求响应解析为POJO(GET)
5. 请求响应解析为手动设置的POJO(GET)/标头
6. 请求无响应(200 - 空体)/标题手动设置/ POJO发送
7. 请求没有响应(200 - 空体)/ POJO发送
8. 没有响应的请求(200 - 空体)/要发送的字符串

当然,为了它的工作原理,你必须拥有谷歌的GSON Lib; 只需添加:

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

你的依赖项(当前版本是2.3.1).

Answer 3

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);

参考

Answer 4

• 创建一个RequestQueue类的对象.

  RequestQueue queue = Volley.newRequestQueue(this);
  

• 创建一个StringRequest带响应和错误监听器.

   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;
      }
  };
  

• 将您的请求添加到RequestQueue.

  queue.add(jsObjRequest);
  

• 创建PostCommentResponseListener界面只是为了让你可以看到它.它是异步请求的简单委托.

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

• 在AndroidManifest.xml文件中包含INTERNET权限.

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