运行应用时出现这些错误。 你可以解释一下如何解决这个错误。 这里是Logcat out put
org.json.JSONException: Value [{"id":2,"username":"myusername","name":"myname","email":"myemail","password":"mypassword","groupid":1,"type":"mytype"},{"id":3,"username":"myusername","name":"myname","email":"myemail2","password":"mypassword2","groupid":1,"type":"mytype"},{"id":4,"username":"username1","name":"name1","email":"email1","password":"pass1","groupid":1,"type":"type1"},{"id":5,"username":"username1","name":"name1","email":"email1","password":"pass1","groupid":1,"type":"type1"},{"id":6,"username":"username1","name":"name1","email":"email1","password":"pass1","groupid":1,"type":"type1"},{"id":7,"username":"username1","name":"name1","email":"email1","password":"pass1","groupid":1,"type":"type1"},{"id":8,"username":"username1","name":"name1","email":"email1","password":"pass1","groupid":1,"type":"type1"},{"id":9,"username":"username1","name":"name1","email":"email1","password":"pass1","groupid":1,"type":"type1"},{"id":10,"username":"username1","name":"name1","email":"email1","password":"pass1","groupid":1,"type":"type1"},{"id":11,"username":"username1","name":"name1","email":"email1","password":"pass1","groupid":1,"type":"1"},{"id":12,"username":"username1","name":"name1","email":"email1","password":"pass1","groupid":1,"type":"type1"},{"id":13,"username":"yuwah","name":"yu","email":"mail@gmail.com","password":"pass1","groupid":1,"type":"type1"},{"id":14,"username":"myusername","name":"myname","email":"myemail2","password":"mypassword2","groupid":1,"type":"mytype"}] at listUsers of type java.lang.String cannot be converted to JSONArray
我的代码块是
public class MainActivity extends ListActivity {
// URL to get contacts JSON
private static String url = "http://staging.workberryplus.com/mobile/listUsers/1";
// JSON Node names
private static final String TAG_USERLIST = "listUsers";
private static final String TAG_ID = "id";
private static final String TAG_NAME = "name";
private static final String TAG_EMAIL = "email";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Calling async task to get json
new GetUsers().execute();
}
/**
* Async task class to get json by making HTTP call
*/
private class GetUsers extends AsyncTask<Void, Void, Void> {
// Hashmap for ListView
ArrayList<HashMap<String, String>> userList;
ProgressDialog pDialog;
@Override
protected void onPreExecute() {
super.onPreExecute();
// Showing progress dialog
pDialog = new ProgressDialog(MainActivity.this);
pDialog.setMessage("Please wait...");
pDialog.setCancelable(false);
pDialog.show();
}
@Override
protected Void doInBackground(Void... arg0) {
// Creating service handler class instance
WebRequest webreq = new WebRequest();
// Making a request to url and getting response
String jsonStr = webreq.makeWebServiceCall(url, WebRequest.GET);
//Log.d("Response: ", "> " + jsonStr);
userList = ParseJSON(jsonStr);
return null;
}
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
// Dismiss the progress dialog
if (pDialog.isShowing())
pDialog.dismiss();
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
MainActivity.this, userList,
R.layout.list_users, new String[]{TAG_NAME, TAG_EMAIL
}, new int[]{R.id.name,
R.id.email});
setListAdapter(adapter);
}
}
private ArrayList<HashMap<String, String>> ParseJSON(String json) {
if (json != null) {
try {
// Hashmap for ListView
ArrayList<HashMap<String, String>> userList = new ArrayList<HashMap<String, String>>();
JSONObject jsonObj = new JSONObject(json);
// Getting JSON Array node
JSONArray students = jsonObj.getJSONArray(TAG_USERLIST);
// looping through All Users
for (int i = 0; i < students.length(); i++) {
JSONObject c = students.getJSONObject(i);
String id = c.getString(TAG_ID);
String name = c.getString(TAG_NAME);
String email = c.getString(TAG_EMAIL);
// tmp hashmap for single user
HashMap<String, String> user = new HashMap<String, String>();
// adding each child node to HashMap key => value
user.put(TAG_ID, id);
user.put(TAG_NAME, name);
user.put(TAG_EMAIL, email);
//student.put(TAG_PHONE_MOBILE, mobile);
// adding users to users list
userList.add(user);
}
return userList;
} catch (JSONException e) {
e.printStackTrace();
return null;
}
} else {
Log.e("ServiceHandler", "Couldn't get any data from the url");
return null;
}
}
}
我是android的初学者。请帮我解决这个错误。我在谷歌搜索，但我无法解决此错误。对不起，我的英语不好。 整个logcat出来是
> 03-31 04:12:01.468 3072-3250/com.nhn.userslist W/System.err: org.json.JSONException: Value [{"id":1,"username":"Nan Oo","name":"nanoo","email":"nann.oo@newhorizonnetworks.com","password":"nanoo","groupid":1,"type":"type1"},{"id":2,"username":"myusername","name":"myname","email":"myemail","password":"mypassword","groupid":1,"type":"mytype"},{"id":3,"username":"myusername","name":"myname","email":"myemail2","password":"mypassword2","groupid":1,"type":"mytype"},{"id":4,"username":"username1","name":"name1","email":"email1","password":"pass1","groupid":1,"type":"type1"},{"id":5,"username":"username1","name":"name1","email":"email1","password":"pass1","groupid":1,"type":"type1"},{"id":6,"username":"username1","name":"name1","email":"email1","password":"pass1","groupid":1,"type":"type1"},{"id":7,"username":"username1","name":"name1","email":"email1","password":"pass1","groupid":1,"type":"type1"},{"id":8,"username":"username1","name":"name1","email":"email1","password":"pass1","groupid":1,"type":"type1"},{"id":9,"username":"username1","name":"name1","email":"email1","password":"pass1","groupid":1,"type":"type1"},{"id":10,"username":"username1","name":"name1","email":"email1","password":"pass1","groupid":1,"type":"type1"},{"id":11,"username":"username1","name":"name1","email":"email1","password":"pass1","groupid":1,"type":"1"},{"id":12,"username":"username1","name":"name1","email":"email1","password":"pass1","groupid":1,"type":"type1"},{"id":13,"username":"yuwah","name":"yu","email":"mail@gmail.com","password":"pass1","groupid":1,"type":"type1"},{"id":14,"username":"myusername","name":"myname","email":"myemail2","password":"mypassword2","groupid":1,"type":"mytype"}] at listUsers of type java.lang.String cannot be converted to JSONArray
03-31 04:12:01.469 3072-3250/com.nhn.userslist W/System.err: at org.json.JSON.typeMismatch(JSON.java:100)
03-31 04:12:01.469 3072-3250/com.nhn.userslist W/System.err: at org.json.JSONObject.getJSONArray(JSONObject.java:588)
03-31 04:12:01.469 3072-3250/com.nhn.userslist W/System.err: at com.nhn.userslist.MainActivity.ParseJSON(MainActivity.java:103)
03-31 04:12:01.469 3072-3250/com.nhn.userslist W/System.err: at com.nhn.userslist.MainActivity.access$200(MainActivity.java:19)
03-31 04:12:01.469 3072-3250/com.nhn.userslist W/System.err: at com.nhn.userslist.MainActivity$GetUsers.doInBackground(MainActivity.java:69)
03-31 04:12:01.469 3072-3250/com.nhn.userslist W/System.err: at com.nhn.userslist.MainActivity$GetUsers.doInBackground(MainActivity.java:42)
03-31 04:12:01.469 3072-3250/com.nhn.userslist W/System.err: at android.os.AsyncTask$2.call(AsyncTask.java:292)
03-31 04:12:01.469 3072-3250/com.nhn.userslist W/System.err: at java.util.concurrent.FutureTask.run(FutureTask.java:237)
03-31 04:12:01.469 3072-3250/com.nhn.userslist W/System.err: at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
03-31 04:12:01.469 3072-3250/com.nhn.userslist W/System.err: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
03-31 04:12:01.469 3072-3250/com.nhn.userslist W/System.err: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
03-31 04:12:01.469 3072-3250/com.nhn.userslist W/System.err: at java.lang.Thread.run(Thread.java:818)
03-31 04:12:01.873 3072-3072/com.nhn.userslist D/AndroidRuntime: Shutting down VM
03-31 04:12:01.873 3072-3072/com.nhn.userslist E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.nhn.userslist, PID: 3072
java.lang.NullPointerException: Attempt to invoke interface method 'int java.util.List.size()' on a null object reference
at android.widget.SimpleAdapter.getCount(SimpleAdapter.java:93)
at android.widget.ListView.setAdapter(ListView.java:487)
at android.app.ListActivity.setListAdapter(ListActivity.java:265)
at com.nhn.userslist.MainActivity$GetUsers.onPostExecute(MainActivity.java:89)
at com.nhn.userslist.MainActivity$GetUsers.onPostExecute(MainActivity.java:42)
at android.os.AsyncTask.finish(AsyncTask.java:636)
at android.os.AsyncTask.access$500(AsyncTask.java:177)
at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:653)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5254)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
03-31 04:12:09.386 3072-3072/com.nhn.userslist I/Process: Sending signal. PID: 3072 SIG: 9
和json值是
[{
"id": 2,
"username": "myusername",
"name": "myname",
"email": "myemail",
"password": "mypassword",
"groupid": 1,
"type": "mytype"
}, {
"id": 3,
"username": "myusername",
"name": "myname",
"email": "myemail2",
"password": "mypassword2",
"groupid": 1,
"type": "mytype"
}, {
"id": 4,
"username": "username1",
"name": "name1",
"email": "email1",
"password": "pass1",
"groupid": 1,
"type": "type1"
}, {
"id": 5,
"username": "username1",
"name": "name1",
"email": "email1",
"password": "pass1",
"groupid": 1,
"type": "type1"
}, {
"id": 6,
"username": "username1",
"name": "name1",
"email": "email1",
"password": "pass1",
"groupid": 1,
"type": "type1"
}, {
"id": 7,
"username": "username1",
"name": "name1",
"email": "email1",
"password": "pass1",
"groupid": 1,
"type": "type1"
}, {
"id": 8,
"username": "username1",
"name": "name1",
"email": "email1",
"password": "pass1",
"groupid": 1,
"type": "type1"
}, {
"id": 9,
"username": "username1",
"name": "name1",
"email": "email1",
"password": "pass1",
"groupid": 1,
"type": "type1"
}, {
"id": 10,
"username": "username1",
"name": "name1",
"email": "email1",
"password": "pass1",
"groupid": 1,
"type": "type1"
}, {
"id": 11,
"username": "username1",
"name": "name1",
"email": "email1",
"password": "pass1",
"groupid": 1,
"type": "1"
}, {
"id": 12,
"username": "username1",
"name": "name1",
"email": "email1",
"password": "pass1",
"groupid": 1,
"type": "type1"
}, {
"id": 13,
"username": "yuwah",
"name": "yu",
"email": "mail@gmail.com",
"password": "pass1",
"groupid": 1,
"type": "type1"
}, {
"id": 14,
"username": "myusername",
"name": "myname",
"email": "myemail2",
"password": "mypassword2",
"groupid": 1,
"type": "mytype"
}]
答案 0 :(得分：1)
根据JSON响应[array {object}]方式，您获得响应，并且您直接使用对象而不获取数组
希望你明白。