我正在尝试将 JSON 解析为列表视图
- 我收到此错误，因为我已在 LOG cat 中发布
- 为什么会发生错误
- 如何解决这个问题
MY-JSON 位置::http://54.218.73.244:7002/
JSONfunctions.java
public class JSONfunctions {
public static JSONObject getJSONfromURL(String url) {
InputStream is = null;
String result = "";
JSONObject jArray = null;
// Download JSON data from URL
try {
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(url);
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
} catch (Exception e) {
Log.e("log_tag", "Error in http connection " + e.toString());
}
// Convert response to string
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());
}
try {
jArray = new JSONObject(result);
} catch (JSONException e) {
Log.e("log_tag", "Error parsing data " + e.toString());
}
return jArray;
}
}
ListViewAdapter.java
public class ListViewAdapter extends BaseAdapter {
// Declare Variables
Context context;
LayoutInflater inflater;
ArrayList<HashMap<String, String>> data;
ImageLoader imageLoader;
HashMap<String, String> resultp = new HashMap<String, String>();
public ListViewAdapter(Context context,
ArrayList<HashMap<String, String>> arraylist) {
this.context = context;
data = arraylist;
imageLoader = new ImageLoader(context);
}
@Override
public int getCount() {
return data.size();
}
@Override
public Object getItem(int position) {
return null;
}
@Override
public long getItemId(int position) {
return 0;
}
public View getView(final int position, View convertView, ViewGroup parent) {
// Declare Variables
TextView rank;
TextView country;
ImageView flag;
inflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View itemView = inflater.inflate(R.layout.listview_item, parent, false);
// Get the position
resultp = data.get(position);
// Locate the TextViews in listview_item.xml
rank = (TextView) itemView.findViewById(R.id.rank);
country = (TextView) itemView.findViewById(R.id.country);
// Locate the ImageView in listview_item.xml
flag = (ImageView) itemView.findViewById(R.id.flag);
// Capture position and set results to the TextViews
rank.setText(resultp.get(MainActivity.NAME));
country.setText(resultp.get(MainActivity.TYPE));
// Capture position and set results to the ImageView
// Passes flag images URL into ImageLoader.class
imageLoader.DisplayImage(resultp.get(MainActivity.FLAG), flag);
// Capture ListView item click
itemView.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// Get the position
resultp = data.get(position);
Intent intent = new Intent(context, SingleItemView.class);
// Pass all data rank
intent.putExtra("name", resultp.get(MainActivity.NAME));
// Pass all data country
intent.putExtra("type", resultp.get(MainActivity.TYPE));
// Pass all data flag
intent.putExtra("flag", resultp.get(MainActivity.FLAG));
// Start SingleItemView Class
context.startActivity(intent);
}
});
return itemView;
}
}
MainActivity.java
public class MainActivity extends Activity {
// Declare Variables
JSONObject jsonobject;
JSONArray jsonarray;
ListView listview;
ListViewAdapter adapter;
ProgressDialog mProgressDialog;
ArrayList<HashMap<String, String>> arraylist;
static String NAME = "rank";
static String TYPE = "country";
static String FLAG = "flag";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Get the view from listview_main.xml
setContentView(R.layout.listview_main);
// Execute DownloadJSON AsyncTask
new DownloadJSON().execute();
}
// DownloadJSON AsyncTask
private class DownloadJSON extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
// Create a progressdialog
mProgressDialog = new ProgressDialog(MainActivity.this);
// Set progressdialog title
mProgressDialog.setTitle("Android JSON Parse Tutorial");
// Set progressdialog message
mProgressDialog.setMessage("Loading...");
mProgressDialog.setIndeterminate(false);
// Show progressdialog
mProgressDialog.show();
}
@Override
protected Void doInBackground(Void... params) {
// Create an array
arraylist = new ArrayList<HashMap<String, String>>();
// Retrieve JSON Objects from the given URL address
jsonobject = JSONfunctions
.getJSONfromURL("http://54.218.73.244:7002/");
try {
// Locate the array name in JSON
jsonarray = jsonobject.getJSONArray("restaurants");
for (int i = 0; i < jsonarray.length(); i++) {
HashMap<String, String> map = new HashMap<String, String>();
jsonobject = jsonarray.getJSONObject(i);
// Retrive JSON Objects
map.put("name", jsonobject.getString("restaurantNAME"));
map.put("type", jsonobject.getString("restaurantTYPE"));
map.put("flag", jsonobject.getString("restaurantIMAGE"));
// Set the JSON Objects into the array
arraylist.add(map);
}
} catch (JSONException e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void args) {
// Locate the listview in listview_main.xml
listview = (ListView) findViewById(R.id.listview);
// Pass the results into ListViewAdapter.java
adapter = new ListViewAdapter(MainActivity.this, arraylist);
// Set the adapter to the ListView
listview.setAdapter(adapter);
// Close the progressdialog
mProgressDialog.dismiss();
}
}
}
日志：：
09-21 19:29:33.245: W/dalvikvm(1041): threadid=6: spin on suspend #1 threadid=9 (pcf=0)
09-21 19:29:33.245: D/dalvikvm(1041): Temporarily moving tid 1051 to fg (was 0)
09-21 19:29:33.245: D/dalvikvm(1041): Temporarily raised priority on tid 1051 (10 -> 0)
09-21 19:29:33.313: W/dalvikvm(1041): threadid=6: spin on suspend resolved in 1088 msec
09-21 19:29:33.323: D/dalvikvm(1041): Restored policy of 1051 to 0
09-21 19:29:33.323: D/dalvikvm(1041): Restored priority on 1051 to 10
09-21 19:29:49.541: E/log_tag(1041): Error parsing data org.json.JSONException: Value Cannot of type java.lang.String cannot be converted to JSONObject
09-21 19:29:49.544: W/dalvikvm(1041): threadid=9: thread exiting with uncaught exception (group=0x40015560)
09-21 19:29:49.663: E/AndroidRuntime(1041): FATAL EXCEPTION: AsyncTask #1
09-21 19:29:49.663: E/AndroidRuntime(1041): java.lang.RuntimeException: An error occured while executing doInBackground()
09-21 19:29:49.663: E/AndroidRuntime(1041): at android.os.AsyncTask$3.done(AsyncTask.java:200)
09-21 19:29:49.663: E/AndroidRuntime(1041): at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:274)
09-21 19:29:49.663: E/AndroidRuntime(1041): at java.util.concurrent.FutureTask.setException(FutureTask.java:125)
09-21 19:29:49.663: E/AndroidRuntime(1041): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:308)
09-21 19:29:49.663: E/AndroidRuntime(1041): at java.util.concurrent.FutureTask.run(FutureTask.java:138)
09-21 19:29:49.663: E/AndroidRuntime(1041): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088)
09-21 19:29:49.663: E/AndroidRuntime(1041): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581)
09-21 19:29:49.663: E/AndroidRuntime(1041): at java.lang.Thread.run(Thread.java:1019)
09-21 19:29:49.663: E/AndroidRuntime(1041): Caused by: java.lang.NullPointerException
09-21 19:29:49.663: E/AndroidRuntime(1041): at com.androidbegin.jsonparsetutorial.MainActivity$DownloadJSON.doInBackground(MainActivity.java:63)
09-21 19:29:49.663: E/AndroidRuntime(1041): at com.androidbegin.jsonparsetutorial.MainActivity$DownloadJSON.doInBackground(MainActivity.java:1)
09-21 19:29:49.663: E/AndroidRuntime(1041): at android.os.AsyncTask$2.call(AsyncTask.java:185)
09-21 19:29:49.663: E/AndroidRuntime(1041): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:306)
09-21 19:29:49.663: E/AndroidRuntime(1041): ... 4 more
09-21 19:29:52.253: E/WindowManager(1041): Activity com.androidbegin.jsonparsetutorial.MainActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@4051f980 that was originally added here
09-21 19:29:52.253: E/WindowManager(1041): android.view.WindowLeaked: Activity com.androidbegin.jsonparsetutorial.MainActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@4051f980 that was originally added here
09-21 19:29:52.253: E/WindowManager(1041): at android.view.ViewRoot.<init>(ViewRoot.java:258)
09-21 19:29:52.253: E/WindowManager(1041): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:148)
09-21 19:29:52.253: E/WindowManager(1041): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91)
09-21 19:29:52.253: E/WindowManager(1041): at android.view.Window$LocalWindowManager.addView(Window.java:424)
09-21 19:29:52.253: E/WindowManager(1041): at android.app.Dialog.show(Dialog.java:241)
09-21 19:29:52.253: E/WindowManager(1041): at com.androidbegin.jsonparsetutorial.MainActivity$DownloadJSON.onPreExecute(MainActivity.java:50)
09-21 19:29:52.253: E/WindowManager(1041): at android.os.AsyncTask.execute(AsyncTask.java:391)
09-21 19:29:52.253: E/WindowManager(1041): at com.androidbegin.jsonparsetutorial.MainActivity.onCreate(MainActivity.java:33)
09-21 19:29:52.253: E/WindowManager(1041): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
09-21 19:29:52.253: E/WindowManager(1041): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
09-21 19:29:52.253: E/WindowManager(1041): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
09-21 19:29:52.253: E/WindowManager(1041): at android.app.ActivityThread.access$1500(ActivityThread.java:117)
09-21 19:29:52.253: E/WindowManager(1041): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
09-21 19:29:52.253: E/WindowManager(1041): at android.os.Handler.dispatchMessage(Handler.java:99)
09-21 19:29:52.253: E/WindowManager(1041): at android.os.Looper.loop(Looper.java:123)
09-21 19:29:52.253: E/WindowManager(1041): at android.app.ActivityThread.main(ActivityThread.java:3683)
09-21 19:29:52.253: E/WindowManager(1041): at java.lang.reflect.Method.invokeNative(Native Method)
09-21 19:29:52.253: E/WindowManager(1041): at java.lang.reflect.Method.invoke(Method.java:507)
09-21 19:29:52.253: E/WindowManager(1041): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
09-21 19:29:52.253: E/WindowManager(1041): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
09-21 19:29:52.253: E/WindowManager(1041): at dalvik.system.NativeStart.main(Native Method)
09-21 19:34:50.023: I/Process(1041): Sending signal. PID: 1041 SIG: 9
有任何想法吗
希望我清楚