通过PHP文件获取JSON时，JSONArray无法转换为JSONObject错误

我知道这里也存在同样的问题，但我认为我的情况不同，我觉得这很令人困惑。当我的JSON链接是

private static String url=”时，我会遇到这个错误http://10.0.2.2/shareity/test.php/";。但是当我在一个文本文件
private static String url=”中有完全相同的JSON数据时http://10.0.2.2/shareity/json.txt";它工作得很好。我的问题是，当我只从PHP文件本身获取JSON时，为什么会发生这种情况

我的日志：

03-30 09:31:01.250: E/JSON Parser(3129): Error parsing data     org.json.JSONException: Value [{"eid":"1","ename":"First","edesc":"Chirath"},    {"eid":"2","ename":"New one","edesc":"Checking if tiisssf"},    {"eid":"3","ename":"Blood Donation","edesc":"Giv the blud"},    {"eid":"4","ename":"Clean","edesc":"cleant eh thin g"}] of type org.json.JSONArray cannot be converted to JSONObject
03-30 09:31:01.260: W/EGL_emulation(3129): eglSurfaceAttrib not implemented
03-30 09:31:01.260: W/OpenGLRenderer(3129): Failed to set EGL_SWAP_BEHAVIOR     on surface 0x7ff0079d5140, error=EGL_SUCCESS
03-30 09:31:01.310: D/AndroidRuntime(3129): Shutting down VM
03-30 09:31:01.310: E/AndroidRuntime(3129): FATAL EXCEPTION: main
03-30 09:31:01.310: E/AndroidRuntime(3129): Process: learn2crack.listview,     PID: 3129
03-30 09:31:01.310: E/AndroidRuntime(3129): java.lang.NullPointerException:     Attempt to invoke virtual method 'org.json.JSONArray     org.json.JSONObject.getJSONArray(java.lang.String)' on a null object reference
03-30 09:31:01.310: E/AndroidRuntime(3129):     at     learn2crack.listview.MainActivity$JSONParse.onPostExecute(MainActivity.java:108)
03-30 09:31:01.310: E/AndroidRuntime(3129):     at     learn2crack.listview.MainActivity$JSONParse.onPostExecute(MainActivity.java:1)
03-30 09:31:01.310: E/AndroidRuntime(3129):     at     android.os.AsyncTask.finish(AsyncTask.java:632)
03-30 09:31:01.310: E/AndroidRuntime(3129):     at     android.os.AsyncTask.access$600(AsyncTask.java:177)
03-30 09:31:01.310: E/AndroidRuntime(3129):     at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:645)
03-30 09:31:01.310: E/AndroidRuntime(3129):     at     android.os.Handler.dispatchMessage(Handler.java:102)
03-30 09:31:01.310: E/AndroidRuntime(3129):     at     android.os.Looper.loop(Looper.java:135)
03-30 09:31:01.310: E/AndroidRuntime(3129):     at     android.app.ActivityThread.main(ActivityThread.java:5221)
03-30 09:31:01.310: E/AndroidRuntime(3129):     at     java.lang.reflect.Method.invoke(Native Method)
03-30 09:31:01.310: E/AndroidRuntime(3129):     at     java.lang.reflect.Method.invoke(Method.java:372)
03-30 09:31:01.310: E/AndroidRuntime(3129):     at     com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
03-30 09:31:01.310: E/AndroidRuntime(3129):     at     com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)

这是我的主要活动

public class MainActivity extends Activity {
ListView list;
TextView eid;
TextView ename;
TextView edesc;
Button Btngetdata;
ArrayList<HashMap<String, String>> oslist = new ArrayList<HashMap<String, String>>();

//URL to get JSON Array
private static String url = "http://10.0.2.2/shareity/test.php/";

//JSON Node Names 
private static final String TAG_OS = "events";
private static final String TAG_EID = "eid";
private static final String TAG_ENAME = "ename";
private static final String TAG_EDESC = "edesc";

JSONArray events = null;




@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_main);
    oslist = new ArrayList<HashMap<String, String>>();



    Btngetdata = (Button)findViewById(R.id.getdata);
    Btngetdata.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View view) {
             new JSONParse().execute();


        }
    });


}



private class JSONParse extends AsyncTask<String, String, JSONObject> {
     private ProgressDialog pDialog;
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
         eid = (TextView)findViewById(R.id.vers);
         ename = (TextView)findViewById(R.id.name);
         edesc = (TextView)findViewById(R.id.api);
        pDialog = new ProgressDialog(MainActivity.this);
        pDialog.setMessage("Getting Data ...");
        pDialog.setIndeterminate(false);
        pDialog.setCancelable(true);
        pDialog.show();



    }

    @Override
    protected JSONObject doInBackground(String... args) {

        JSONParser jParser = new JSONParser();

        // Getting JSON from URL
        JSONObject json = jParser.getJSONFromUrl(url);
        return json;
    }
     @Override
     protected void onPostExecute(JSONObject json) {
         pDialog.dismiss();
         try {
                // Getting JSON Array from URL
                events = json.getJSONArray(TAG_OS);
                for(int i = 0; i < events.length(); i++){
                JSONObject c = events.getJSONObject(i);

                // Storing  JSON item in a Variable
                String eid = c.getString(TAG_EID);
                String ename = c.getString(TAG_ENAME);
                String edesc = c.getString(TAG_EDESC);




                // Adding value HashMap key => value


                HashMap<String, String> map = new HashMap<String, String>();

                map.put(TAG_EID, eid);
                map.put(TAG_ENAME, ename);
                map.put(TAG_EDESC, edesc);

                oslist.add(map);
                list=(ListView)findViewById(R.id.list);





                ListAdapter adapter = new SimpleAdapter(MainActivity.this, oslist,
                        R.layout.list_v,
                        new String[] { TAG_EID,TAG_ENAME, TAG_EDESC }, new int[] {
                                R.id.vers,R.id.name, R.id.api});

                list.setAdapter(adapter);
                list.setOnItemClickListener(new AdapterView.OnItemClickListener() {

                    @Override
                    public void onItemClick(AdapterView<?> parent, View view,
                                            int position, long id) {
                        Toast.makeText(MainActivity.this, "You Clicked at "+oslist.get(+position).get("name"), Toast.LENGTH_SHORT).show();

                    }
                });

                }
        } catch (JSONException e) {
            e.printStackTrace();
        }


     }
}

}

试试这个，它会有用的
将以下内容放在php代码的顶部

header('Content-Type: application/json');

首先关闭mysql连接而不是fclose（我不确定）

您可以从字符串创建jsonObject，但是这个字符串是jsonarray

JSONArray jsonArray = new JSONArray(yourJSONString);
for(int i = 0; i < jsonArray.length(); i++) {
    JSONObject jsonObj = jsonArray.getJSONObject(i);
}

JSONArray-JSONArray=newjsonarray（yourJSONString）；
for（int i=0；i
显然，请学习如何使用谷歌…@Selvin，我知道如何使用谷歌。这就是为什么我在问题的开头提到，我相信我的案例与其他案例不同。问题在于我的PHP代码。不是安卓。谢谢你的帮助，顺便说一句：）哈哈。。。你甚至不明白其他的问题。。。替换
JSONObject jObj=新的JSONObject（json）
with
JSONArray jObj=新的JSONArray（json）也应该做到这一点。。。基本上，你只是复制粘贴一些代码而不理解它。。。这不是编程哦，是吗？我不知道。我是自学型安卓，而且我是个新手。请不要嘲笑我。我很确定你在某个时候是这样的，它可能有用？这不是这个错误的原因…我希望你的答案，谢谢，伙计，从字符串形成json，它必须是有效的json，这里OP没有发布从php收到的确切json。当然没有。。。org.json.JSONException:Value[{“eid”：“1”，“ename”：“First”，“edesc”：“Chirath”}，{“eid”：“2”，“ename”：“New one”，“edesc”：“Checking if tiisssf”}，{“eid”：“Blood exection”，“edesc”：“Giv the blud”}，{“eid”：“4”，“ename”：“Clean”，“edesc”：“cleant eh thin g”}类型org.json.JSONArray无法转换为JSONObject。。。这里是$json_response=array（）。。。echo json_编码（$json_响应）@塞尔文，我现在明白了。在PHP代码中，缺少
{“events”：
。我如何获得它？我应该向PHP代码中添加什么代码？请帮助我，我对所有这些都是新手：（我已经在PHP部分更正了您的代码，echo json_encode（array（'events'=>$json_response））；
header('Content-Type: application/json');

mysql_close();

echo json_encode(array('events'=>$json_response));

JSONArray jsonArray = new JSONArray(yourJSONString);
for(int i = 0; i < jsonArray.length(); i++) {
    JSONObject jsonObj = jsonArray.getJSONObject(i);
}