使用 volley 进行 web 服务调用

Question

我有一个 web api 设置，API 中的一个端点采用 JSON 对象（在 API 中被解析为 .NET 对象）。

使用 Postman 我可以成功调用 post 端点，这里是 URL

https://example.com/api/helprequests

这是我在 Postman 请求中包含的 JSON

{"Title":"Test Title", "Message":"Test Message"}

在 Postman 中一切正常，但我正在尝试使用 Volley 从 Android 应用程序调用此 API。

这里是相关代码

String webAddress = "http://example.com/api/helprequests/";
RequestQueue queue = Volley.newRequestQueue(this);
StringRequest stringRequest = new StringRequest(Request.Method.POST, webAddress,
        new Response.Listener<String>() {
            @Override
            public void onResponse(String response) {
                Log.d("RESPONSE", response);
            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                Log.d("RESPONSE", "That didn't work!");
            }
        }) {
            @Override
            public String getBodyContentType() {
                return "application/json";
            }
            @Override
            public byte[] getBody() throws AuthFailureError {
                try {
                    Map<String, String> params = new HashMap<String, String>();
                    params.put("Title","Test title");
                    params.put("Message", "Test message");
                } catch (Exception ex) {
                    VolleyLog.wtf("Unsupported Encoding");
                    return null;
                }
                return null;
            }
        };
queue.add(stringRequest);

当我运行它时，我收到以下错误：

E/Volley: [50225] BasicNetwork.performRequest: Unexpected response code 500 for https://example.com/api/helprequests

如何将帖子数据添加到 Volley 请求？

Answer 1

不要使用StringRequest，而是使用JsonObjectRequest。

 String webAddress = "http://example.com/api/helprequests/";
 RequestQueue queue = Volley.newRequestQueue(this);

 JSONObject object = new JSONObject();
 try {
     object.put("Title", "my title");
     object.put("Message", "my message");
 } catch (JSONException e) {
 }

 JsonObjectRequest request = new JsonObjectRequest(Request.Method.POST, webAddress,object, new Response.Listener<JSONObject>() {

     @Override
     public void onResponse(JSONObject object) {
         Log.d("RESPONSE", object.toString());
     }

 }, new Response.ErrorListener() {

     @Override
     public void onErrorResponse(VolleyError volleyError) {
         Log.d("RESPONSE", "That didn't work!");
     }

 });
 queue.add(request);

Answer 2

String webAddress = "http://example.com/api/helprequests/";
 RequestQueue queue = Volley.newRequestQueue(this);

 JSONObject jsonObject= new JSONObject();
 try {
     jsonObject.put("Title", "my title");
     jsonObject.put("Message", "my message");
 } catch (JSONException e) {
 }

RequestQueue queue = Volley.newRequestQueue(getApplicationContext());
        JsonObjectRequestWithHeader jsonObjReq = new JsonObjectRequestWithHeader(Request.Method.POST,
                webAddress , jsonObject, new Response.Listener<JSONObject>() {
            @Override
            public void onResponse(JSONObject response) {
                Log.v("Response0", response.toString());
}
}, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                VolleyLog.d("Response", "Error: " + error.getMessage());
                pd.dismiss();

            }
        });
        int socketTimeout = 50000;//30 seconds - change to what you want
        RetryPolicy policy = new DefaultRetryPolicy(socketTimeout, DefaultRetryPolicy.DEFAULT_MAX_RETRIES,
                DefaultRetryPolicy.DEFAULT_BACKOFF_MULT);
        jsonObjReq.setRetryPolicy(policy);
        queue.add(jsonObjReq);
        return null;
    }