[Android] Force close when trying to parse JSON with AsyncTask in the background
- by robs
Hello everyone,
i'm new to android development and i'm playing around with json data. I managed to get the parsing to work. I want to show a ProgressDialog and i read that i need to use AsyncTask that. But for some reason i get a force close as soon as i put the same working code inside doInBackground() eventhough eclipse says everything is fine.
Here is the source code:
public class HomeActivity extends Activity {
public class BackgroundAsyncTask extends AsyncTask<Void, Integer, Void> {
ProgressDialog dialog = new ProgressDialog (HomeActivity.this);
@Override
protected void onPreExecute() {
dialog.setMessage("Loading...please wait");
dialog.setIndeterminate(true);
dialog.setCancelable(false);
dialog.show();
}
protected void onPostExecute() {
dialog.dismiss();
}
@Override
protected Void doInBackground(Void... params) {
try {
URL json = new URL("http://www.corps-marchia.de/jsontest.php");
URLConnection tc = json.openConnection();
BufferedReader in = new BufferedReader(new InputStreamReader(tc.getInputStream()));
String line;
while ((line = in.readLine()) != null) {
JSONArray ja = new JSONArray(line);
JSONObject jo = (JSONObject) ja.get(0);
TextView txtView = (TextView)findViewById(R.id.TextView01);
txtView.setText(jo.getString("text"));
}
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
new BackgroundAsyncTask().execute();
}
}
Here is the error log:
01-08 12:33:48.225: ERROR/AndroidRuntime(815): FATAL EXCEPTION: AsyncTask #1
01-08 12:33:48.225: ERROR/AndroidRuntime(815): java.lang.RuntimeException: An error occured while executing doInBackground()
01-08 12:33:48.225: ERROR/AndroidRuntime(815): at android.os.AsyncTask$3.done(AsyncTask.java:200)
01-08 12:33:48.225: ERROR/AndroidRuntime(815): at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:274)
01-08 12:33:48.225: ERROR/AndroidRuntime(815): at java.util.concurrent.FutureTask.setException(FutureTask.java:125)
01-08 12:33:48.225: ERROR/AndroidRuntime(815): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:308)
01-08 12:33:48.225: ERROR/AndroidRuntime(815): at java.util.concurrent.FutureTask.run(FutureTask.java:138)
01-08 12:33:48.225: ERROR/AndroidRuntime(815): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088)
01-08 12:33:48.225: ERROR/AndroidRuntime(815): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581)
01-08 12:33:48.225: ERROR/AndroidRuntime(815): at java.lang.Thread.run(Thread.java:1019)
01-08 12:33:48.225: ERROR/AndroidRuntime(815): Caused by: android.view.ViewRoot$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.
01-08 12:33:48.225: ERROR/AndroidRuntime(815): at android.view.ViewRoot.checkThread(ViewRoot.java:2932)
01-08 12:33:48.225: ERROR/AndroidRuntime(815): at android.view.ViewRoot.requestLayout(ViewRoot.java:629)
01-08 12:33:48.225: ERROR/AndroidRuntime(815): at android.view.View.requestLayout(View.java:8267)
01-08 12:33:48.225: ERROR/AndroidRuntime(815): at android.view.View.requestLayout(View.java:8267)
01-08 12:33:48.225: ERROR/AndroidRuntime(815): at android.view.View.requestLayout(View.java:8267)
01-08 12:33:48.225: ERROR/AndroidRuntime(815): at android.view.View.requestLayout(View.java:8267)
01-08 12:33:48.225: ERROR/AndroidRuntime(815): at android.view.View.requestLayout(View.java:8267)
01-08 12:33:48.225: ERROR/AndroidRuntime(815): at android.widget.TextView.checkForRelayout(TextView.java:5521)
01-08 12:33:48.225: ERROR/AndroidRuntime(815): at android.widget.TextView.setText(TextView.java:2724)
01-08 12:33:48.225: ERROR/AndroidRuntime(815): at android.widget.TextView.setText(TextView.java:2592)
01-08 12:33:48.225: ERROR/AndroidRuntime(815): at android.widget.TextView.setText(TextView.java:2567)
01-08 12:33:48.225: ERROR/AndroidRuntime(815): at net.ajzele.demo.andy1.HomeActivity$BackgroundAsyncTask.doInBackground(HomeActivity.java:52)
01-08 12:33:48.225: ERROR/AndroidRuntime(815): at net.ajzele.demo.andy1.HomeActivity$BackgroundAsyncTask.doInBackground(HomeActivity.java:1)
01-08 12:33:48.225: ERROR/AndroidRuntime(815): at android.os.AsyncTask$2.call(AsyncTask.java:185)
01-08 12:33:48.225: ERROR/AndroidRuntime(815): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:306)
01-08 12:33:48.225: ERROR/AndroidRuntime(815): ... 4 more
01-08 12:33:51.605: ERROR/WindowManager(815): Activity net.ajzele.demo.andy1.HomeActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@4051d0c0 that was originally added here
01-08 12:33:51.605: ERROR/WindowManager(815): android.view.WindowLeaked: Activity net.ajzele.demo.andy1.HomeActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@4051d0c0 that was originally added here
01-08 12:33:51.605: ERROR/WindowManager(815): at android.view.ViewRoot.<init>(ViewRoot.java:258)
01-08 12:33:51.605: ERROR/WindowManager(815): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:148)
01-08 12:33:51.605: ERROR/WindowManager(815): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91)
01-08 12:33:51.605: ERROR/WindowManager(815): at android.view.Window$LocalWindowManager.addView(Window.java:424)
01-08 12:33:51.605: ERROR/WindowManager(815): at android.app.Dialog.show(Dialog.java:241)
01-08 12:33:51.605: ERROR/WindowManager(815): at net.ajzele.demo.andy1.HomeActivity$BackgroundAsyncTask.onPreExecute(HomeActivity.java:33)
01-08 12:33:51.605: ERROR/WindowManager(815): at android.os.AsyncTask.execute(AsyncTask.java:391)
01-08 12:33:51.605: ERROR/WindowManager(815): at net.ajzele.demo.andy1.HomeActivity.onCreate(HomeActivity.java:72)
01-08 12:33:51.605: ERROR/WindowManager(815): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
01-08 12:33:51.605: ERROR/WindowManager(815): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1586)
01-08 12:33:51.605: ERROR/WindowManager(815): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1638)
01-08 12:33:51.605: ERROR/WindowManager(815): at android.app.ActivityThread.access$1500(ActivityThread.java:117)
01-08 12:33:51.605: ERROR/WindowManager(815): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:928)
01-08 12:33:51.605: ERROR/WindowManager(815): at android.os.Handler.dispatchMessage(Handler.java:99)
01-08 12:33:51.605: ERROR/WindowManager(815): at android.os.Looper.loop(Looper.java:123)
01-08 12:33:51.605: ERROR/WindowManager(815): at android.app.ActivityThread.main(ActivityThread.java:3647)
01-08 12:33:51.605: ERROR/WindowManager(815): at java.lang.reflect.Method.invokeNative(Native Method)
01-08 12:33:51.605: ERROR/WindowManager(815): at java.lang.reflect.Method.invoke(Method.java:507)
01-08 12:33:51.605: ERROR/WindowManager(815): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
01-08 12:33:51.605: ERROR/WindowManager(815): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
01-08 12:33:51.605: ERROR/WindowManager(815): at dalvik.system.NativeStart.main(Native Method)
Any hints? I hope you can help me out ive searched the net and didnt find any working solution...Thanks in advance
