How to stop or destroy an Android thread

Question

I know that the stop method has been deprecated and I am using destroy now, but I get this error:

11-09 11:42:28.740: E/AndroidRuntime(1538): FATAL EXCEPTION: main
11-09 11:42:28.740: E/AndroidRuntime(1538): java.lang.NoSuchMethodError: Thread.destroy()
11-09 11:42:28.740: E/AndroidRuntime(1538):     at java.lang.Thread.destroy(Thread.java:600)
11-09 11:42:28.740: E/AndroidRuntime(1538):     at com.rathbones.src.NewslettersActivity.onKeyDown(NewslettersActivity.java:144)
11-09 11:42:28.740: E/AndroidRuntime(1538):     at android.view.KeyEvent.dispatch(KeyEvent.java:1037)
11-09 11:42:28.740: E/AndroidRuntime(1538):     at android.app.Activity.dispatchKeyEvent(Activity.java:2068)
11-09 11:42:28.740: E/AndroidRuntime(1538):     at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchKeyEvent(PhoneWindow.java:1643)
11-09 11:42:28.740: E/AndroidRuntime(1538):     at android.view.ViewRoot.deliverKeyEventToViewHierarchy(ViewRoot.java:2471)
11-09 11:42:28.740: E/AndroidRuntime(1538):     at android.view.ViewRoot.handleFinishedEvent(ViewRoot.java:2441)
11-09 11:42:28.740: E/AndroidRuntime(1538):     at android.view.ViewRoot.handleMessage(ViewRoot.java:1735)
11-09 11:42:28.740: E/AndroidRuntime(1538):     at android.os.Handler.dispatchMessage(Handler.java:99)
11-09 11:42:28.740: E/AndroidRuntime(1538):     at android.os.Looper.loop(Looper.java:123)
11-09 11:42:28.740: E/AndroidRuntime(1538):     at android.app.ActivityThread.main(ActivityThread.java:4627)
11-09 11:42:28.740: E/AndroidRuntime(1538):     at java.lang.reflect.Method.invokeNative(Native Method)
11-09 11:42:28.740: E/AndroidRuntime(1538):     at java.lang.reflect.Method.invoke(Method.java:521)
11-09 11:42:28.740: E/AndroidRuntime(1538):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
11-09 11:42:28.740: E/AndroidRuntime(1538):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
11-09 11:42:28.740: E/AndroidRuntime(1538):     at dalvik.system.NativeStart.main(Native Method)
11-09 11:42:28.760: W/ActivityManager(59):   Force finishing activity com.rathbones.src/.NewslettersActivity

The application is not crashing, it's just that I get this error in logcat.

Actually I have a newsletter module which enables users to view the PDF file. When they press the view button it opens up a progress bar and in the same time if someone presses the backbutton it should stop the thread and exit gracefully. It does that but in the log I get the above error.

Here is the code snippet causing this error:

private void viewOnline() {

        if (currentNewsletter == null) {
            Log.e(Constants.APP_NAME, "No newsletter selected");
            return;
        }

        final ProgressDialog d = new ProgressDialog(this);
        d.setMessage("Downloading...");
        d.show();

        final Context context = getApplicationContext();
         t = new Thread(new Runnable() {
            public void run() {

                String fileName = currentNewsletter.mFilename;

                Log.d(Constants.APP_NAME, "Downloading/showing: " + fileName);
                final File file = Utilities.getFileFromURL(context, currentNewsletter.mUrl, currentNewsletter.mExpectedSizeInBytes, fileName, false);

                d.dismiss();
                // Now we can show the file
                viewPDF(file);
            }
        });
        t.start();

        // Utilities.List(getApplicationContext().getFilesDir().getPath());
        // Utilities.List(getApplicationContext().getDir("files", Context.MODE_WORLD_WRITEABLE).getAbsolutePath());
        // Utilities.DeleteDirectory(getApplicationContext().getDir("files", Context.MODE_WORLD_WRITEABLE).getAbsolutePath());

    }

    private void viewPDF(File file) {

        //DEBUG DEBUG DEBUG
        //Log.d(Constants.APP_NAME, "ViewPDF: showing " + file.getName());
        //Log.d(Constants.APP_NAME, "Path: " + file.getPath());
        //Log.d(Constants.APP_NAME, "Exists: " + file.exists());
        //Log.d(Constants.APP_NAME, "Length: " + file.length());
        //DEBUG DEBUG DEBUG

        // Now it's all safe and sound and local, open it
        Intent intent = new Intent(Intent.ACTION_VIEW);
        intent.setDataAndType(Uri.fromFile(file), "application/pdf");

        try {
            startActivity(intent);
        } catch (Exception e) {
            Toast.makeText(this, "No Application Available to View PDF", Toast.LENGTH_SHORT).show();
        }
    }

    @Override
    protected void onStop() {
        finish();
        super.onStop();
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if (keyCode == KeyEvent.KEYCODE_BACK) {
            t.destroy();
           Intent i = new Intent(NewslettersActivity.this,MainMenuActivity.class);

           startActivity(i);
           finish();
            return true;
        }
        return super.onKeyDown(keyCode, event);
    }

Solution 1

If you have a thread with a while loop inside, you can control this thread by a boolean flag for the while condition. When you set the flag to false the thread just finishes its task.

Here's a little example:

boolean flag = true;
Thread secondary = new Thread(new Runnable() {

@Override
public void run() {
    while (flag) {
    // do something
    }
 }
});

secondary.start(); //start the thread
flag = false; // this will force secondary to finish its execution
 try {
   secondary.join(); // wait for secondary to finish
   } catch (InterruptedException e) {
    throw new RuntimeException(e);
}

I will found this code in SO and it also works for me.

Solution 2

Use interrupt() instead of destroy().

Comments

[Vineet Shukla]

destroy is also deprecated. Follow this link:developer.android.com/reference/java/lang/…

[Maverick]

@VineetShukla thanks for letting me know that.

[Maverick]

Could you tell me in more detail please.

[Maverick]

well..it looks a very logical solution..just trying it out now..and will let you know

[Quentin DOMMERC]

Then follow this: stackoverflow.com/questions/5241822/…

[user370305]

@Dipak Keshariya - Without seeing what are you tried, How you implemented this code in your app we can't say anything. Put your problem in SO as a new question with Exception what you getting.

[Dipak Keshariya]

pls see my question, stackoverflow.com/questions/9817941/stop-current-thread-issu‌​e