如何从 Android 发布 JSON 字符串

Question

尝试从 Android 在服务器上发布 json 时遇到问题。错误是：

加载 JSON 失败。特殊字符不能包含在 要求。请检查请求的 JSON。

我遵循了许多示例，但没有一个有用。请提出解决方案或帮我找出代码中的问题。

以下是在服务器上发布 JSON 字符串的代码。

public class JSONParser {

    static InputStream is = null;
    static JSONObject jObj = null;
    static String json = "";

    // constructor
    public JSONParser() {

    }

    public JSONObject getJSONFromUrl(String url) {

        // Making HTTP request
        try {
            // defaultHttpClient
            DefaultHttpClient httpClient = new DefaultHttpClient();
            HttpPost httpPost = new HttpPost(url);
            /* ====================================================================================================*/

                        JSONObject listobj = new JSONObject ();
                        JSONObject listInvoice = new JSONObject ();
                        listInvoice.put("client_id","");
                        listInvoice.put("date_from","");
                        listInvoice.put("date_to","");
                        listInvoice.put("invoice_number","");
                        listInvoice.put("invoice_record_status","");
                        listInvoice.put("invoice_status","");
                        listInvoice.put("page","1");
                        listInvoice.put("per_page_record","10");
                        listobj.put("listInvoice", listInvoice);


                      //--List nameValuePairs = new ArrayList(1);
                        List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(1);
                        nameValuePairs.add(new BasicNameValuePair("json_data", listobj.toString()));


                        httpPost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
                        Log.d("JSON",listobj.toString());
            /*======================================================================================================*/

            HttpResponse httpResponse = httpClient.execute(httpPost);
            String is = EntityUtils.toString(httpResponse.getEntity());

            Log.d("JSON","RESPONSE : " + is);

            //--HttpEntity httpEntity = httpResponse.getEntity();
            //--is = httpEntity.getContent();           

        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        catch (JSONException e) {
            Log.e("JSON",e.getMessage());
     }

        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    is, "iso-8859-1"), 8);
            StringBuilder sb = new StringBuilder();
            String line = null;
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }
            is.close();
            json = sb.toString();
        } catch (Exception e) {
            Log.e("Buffer Error", "Error converting result " + e.toString());
        }

        // try parse the string to a JSON object
        try {
            jObj = new JSONObject(json);
        } catch (JSONException e) {
            Log.e("JSON Parser", "Error parsing data " + e.toString());
        }

        // return JSON String
        return jObj;

      }
     }
}

Answer 1

这是将 json 传递给你的 URL 的函数

public void getServerData() throws JSONException, ClientProtocolException, IOException {

    String title = Title_edittext.getText().toString().trim();
    String details = Details_edittext.getText().toString().trim();

    HttpParams httpParams = new BasicHttpParams();
    HttpConnectionParams.setConnectionTimeout(httpParams, TIMEOUT_MILLISEC);
    HttpConnectionParams.setSoTimeout(httpParams, TIMEOUT_MILLISEC);
    HttpClient client = new DefaultHttpClient(httpParams);
    HttpPost request = new HttpPost(url); // add your url here...

    request.setHeader( "Content-Type", "application/json" );        

    JSONObject json = new JSONObject();     
    json.put("client_id", channel_token);
    json.put("date_from", data_src_id);
    json.put("date_to", title);  

    Log.i("JSON Object", json.toString());

    StringEntity se = new StringEntity(json.toString());

    se.setContentEncoding("UTF-8");
    se.setContentType("application/json");

    request.setEntity(se);      

    HttpResponse response = client.execute(request); 

    HttpEntity entity = response.getEntity();
    InputStream is = entity.getContent();
    String _response = convertStreamToString(is);
    System.out.println("res--  " + _response);

    // Check if server response is valid code          
    int res_code = response.getStatusLine().getStatusCode();
    System.out.println("code-- " +res_code);
}
private static String convertStreamToString(InputStream is) {

    BufferedReader reader = new BufferedReader(new InputStreamReader(is), 8192);
    StringBuilder sb = new StringBuilder();

    String line = null;
    try {
        while ((line = reader.readLine()) != null) {
            sb.append((line + "\n"));
        }
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        try {
            is.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    return sb.toString();
}

Answer 2

这里是链接How to send a JSON object over Request with Android?

int TIMEOUT_MILLISEC = 10000;  // = 10 seconds
HttpParams httpParams = new BasicHttpParams();
HttpConnectionParams.setConnectionTimeout(httpParams, TIMEOUT_MILLISEC);
HttpConnectionParams.setSoTimeout(httpParams, TIMEOUT_MILLISEC);
HttpClient client = new DefaultHttpClient(httpParams);

HttpPost request = new HttpPost(serverUrl);
request.setEntity(new ByteArrayEntity(
    postMessage.toString().getBytes("UTF8")));
HttpResponse response = client.execute(request);

看这行：request.setEntity(new ByteArrayEntity( postMessage.toString().getBytes("UTF8")));