org.json.JSONException：java.lang.String 类型的值无法转换为 JSONObject

Question

您好，我在 2.3 中遇到了 Android JSON Parser 的问题，在 4.0 中一切正常>。

我查看了他们在谈论编码（服务器）或其他服务器端的其他主题，但我尝试在我的所有 JSON 字段中放置“测试”，但问题仍然存在。

这是我的代码：

URL url = new URL(c.getString(R.string.url_ws) + url_ws);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoOutput(true);
connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
connection.setRequestMethod("POST");
OutputStreamWriter request = new OutputStreamWriter(connection.getOutputStream());
request.write("&test=test");
request.flush();
request.close();


String line;
InputStreamReader isr = new InputStreamReader(connection.getInputStream());
BufferedReader reader = new BufferedReader(isr);
StringBuilder sb = new StringBuilder();

while ((line = reader.readLine()) != null){
    sb.append(line + "\n");
}
String json = sb.toString().trim();
try {
     JSONObject obj = new JSONObject(json);
} catch (JSONException e) {
    e.printStackTrace();
    Log.d(Tools.TAG+"/debug JSONException", e.toString());
    return null;
}

这是我的例外

debug JSONException(4184): org.json.JSONException: Value  of type java.lang.String cannot be converted to JSONObject

我看到“Value”和“of”之间有两个空格，所以我猜问题是一个空字符串，但我不明白。

谢谢。

编辑

这是我的 JSON 中的编码错误，

char a = json.substring(0, 1).charAt(0);
int ascii = (int)a;
Tools.myLog(">"+ascii+"<"); 

我找到了 65279 个字符

解决方案

Why is  appearing in my HTML?

在没有 BOM 的情况下编码 UTF-8。

Answer 1

while ((line = reader.readLine()) != null){
    sb.append(line + "\n");
}

不如试试

while ((line = reader.readLine()) != null){
    sb.append(line);
   json = sb.toString().substring(0, sb.toString().length()-1);
}

按照这个方法获取json对象：

 public JSONObject getJSONObjFromUrl(String url, List<NameValuePair> params) {      
            System.out.println("url:: "+url );
            System.out.println("params:: "+ params +" " +params.get(0) );
            // Making HTTP request
            try {
                // defaultHttpClient
                DefaultHttpClient httpClient = new DefaultHttpClient();
                HttpPost httpPost = new HttpPost(url);
                httpPost.setEntity(new UrlEncodedFormEntity(params));

                HttpResponse httpResponse = httpClient.execute(httpPost);
                HttpEntity httpEntity = httpResponse.getEntity();
                is = httpEntity.getContent();

            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            } catch (ClientProtocolException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }

            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);
                }
                is.close();

                json = sb.toString().substring(0, sb.toString().length()-1);
               // Log.e("JSON:: ", json);
            } 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;

        }