Question

我已将数据插入名为tsk的服务器表中。现在我想在我的Android代码中使用JsonArray检索它。我使用了以下php code，我可以在网页上看到解析后的数组。问题是我在错误日志中收到错误04-04 01:36:18.198: E/log_tag(2254): Error parsing data org.json.JSONException: Value of type java.lang.String cannot be converted to JSONArray。

我的数据库字段如下： tid是Int设置为primary key和autoincremented。 stat是Text，字段长度设置为100。 r是VarChar，长度设置为100。

我在Android中的Json检索代码如下：

    String result = null;
    InputStream is = null;
    try{
        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost("myurl");
        ArrayList<NameValuePair>  nameValuePairs = new ArrayList<NameValuePair>();
       HttpResponse response = httpclient.execute(httppost); 
        HttpEntity entity = response.getEntity();
        is = entity.getContent();

        Log.e("log_tag", "connection success ");

}
    catch(Exception e)
    {
            Log.e("log_tag", "Error in http connection "+e.toString());
            Toast.makeText(getActivity(), "Connection fail", Toast.LENGTH_SHORT).show();

    }
    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();

            result=sb.toString();
    }
    catch(Exception e)
    {
           Log.e("log_tag", "Error converting result "+e.toString());
        Toast.makeText(getActivity(), " Input reading fail", Toast.LENGTH_SHORT).show();

    }
    try
    {
        JSONArray jArray = new JSONArray(result);
        String s="",s1,s2,s3,s4,s5;
        Log.w("Lengh",""+jArray.length());
          for(int i=0;i<jArray.length();i++){

            //  final ListView lview=(ListView) rootView.findViewById(R.id.listViewmytask);
            JSONObject json_data = jArray.getJSONObject(i);

                s=json_data.getString("stat");
                Log.i("taskid",""+s);
  }
  }

  catch(JSONException e)
    {
            Log.e("log_tag", "Error parsing data "+e.toString());
            Toast.makeText(getActivity(), "JsonArray fail", Toast.LENGTH_SHORT).show();
    }

JSON reesponse：

   [{"tid":"9","head":"task2","des":"task2.2","dateone":"2014\/4\/4 ","datetwo":"","timeone":"12:18","timetwo":"13:18","r":"123","s":"123456","stat":"not defined"},
    {"tid":"8","head":"task1","des":"task1.1","dateone":"2014\/4\/4 ","datetwo":"","timeone":"12:11","timetwo":"13:11","r":"12345","s":"123456","stat":"not defined"},
    {"tid":"10","head":"task3","des":"task3.3","dateone":"2014\/4\/3 ","datetwo":"2014\/5\/3 ","timeone":"13:25","timetwo":"13:26","r":"456","s":"123456","stat":"not defined"},    {"tid":"11","head":"task4","des":"task4.4","dateone":"2014\/3\/31 ","datetwo":"2014\/4\/30 ","timeone":"13:30","timetwo":"14:30","r":"123456","s":"123456","stat":"not defined"}]

String Builder result显示以下值：但它有一些未定义的字符，如i`？（倒置问号）。

  04-04 01:44:04.965: I/result(2406): i`?[{"tid":"10","head":"task3","des":"task3.3","dateone":"2014-4-3 ","datetwo":"2014-5-3 ","timeone":"13:25","timetwo":"13:26","r":"456","s":"123456","stat":"not defined"}]

Answer 1

可能是因为JSON响应格式不正确。您可以发布您的JSON响应以更好地理解它吗？您可以在此网址中验证您的JSON响应 - http://jsonlint.com/

您可以使用这个简单的JSON解析器来解析您的JSON响应 - https://json-simple.googlecode.com/files/json-simple-1.1.1.jar。

Answer 2

似乎服务器没有返回jsonArray，确保第一个响应字母，如果它启动{应该是json对象而且如果服务器只返回'[]'这个那么服务器返回空数据，这不可能是解析成json数组

Answer 3

更改此代码并尝试

StringBuilder sb = new StringBuilder();
        BufferedReader reader = new BufferedReader(new InputStreamReader(is, HTTP.UTF_8));
        String line = null;
        try {
            while ((line = reader.readLine()) != null) {
                sb.append(line);
            }

        } finally {
            is.close();
            reader.close();
        }
        result=sb.toString();

为什么我不能在Android中使用JsonArray检索数据？

3 个答案: