I want to stop a running thread while click on the splash screen, if I don't click on screen, after the thread execution, it will launch another Activity. But getting UnSupportedException, how do I solve it?
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_splash);
iImage = (ImageView) findViewById(R.id.iIcon);
splashImage = (ImageView) findViewById(R.id.splash_image);
iImage.setOnClickListener(this);
splashImage.setOnClickListener(this);
}
#Override
protected void onStart() {
super.onStart();
splashTimer = new Thread(new Runnable() {
#Override
public void run() {
try {
Thread.sleep(5000);
} catch (InterruptedException e) {
e.printStackTrace();
}
startActivity(new Intent(SplashActivity.this, LoginAuthenticationActivity.class));
finish();
}
});
splashTimer.start();
}
#Override
public void onClick(View view) {
if(splashTimer.isAlive())
splashTimer.stop();
switch (view.getId()) {
case R.id.iIcon:
startActivity(new Intent(this, AboutUsActivity.class));
break;
case R.id.splash_image:
startActivity(new Intent(this, LoginAuthenticationActivity.class));
break;
default:
break;
}
finish();
}
Log:
01-27 03:27:01.189: W/dalvikvm(1080): threadid=1: thread exiting with uncaught exception (group=0x409c01f8)
01-27 03:27:01.209: E/AndroidRuntime(1080): FATAL EXCEPTION: main
01-27 03:27:01.209: E/AndroidRuntime(1080): java.lang.UnsupportedOperationException
01-27 03:27:01.209: E/AndroidRuntime(1080): at java.lang.Thread.stop(Thread.java:1076)
01-27 03:27:01.209: E/AndroidRuntime(1080): at java.lang.Thread.stop(Thread.java:1063)
01-27 03:27:01.209: E/AndroidRuntime(1080): at com.app.wooqer.SplashActivity.onClick(SplashActivity.java:48)
01-27 03:27:01.209: E/AndroidRuntime(1080): at android.view.View.performClick(View.java:3511)
01-27 03:27:01.209: E/AndroidRuntime(1080): at android.view.View$PerformClick.run(View.java:14105)
01-27 03:27:01.209: E/AndroidRuntime(1080): at android.os.Handler.handleCallback(Handler.java:605)
01-27 03:27:01.209: E/AndroidRuntime(1080): at android.os.Handler.dispatchMessage(Handler.java:92)
01-27 03:27:01.209: E/AndroidRuntime(1080): at android.os.Looper.loop(Looper.java:137)
01-27 03:27:01.209: E/AndroidRuntime(1080): at android.app.ActivityThread.main(ActivityThread.java:4424)
01-27 03:27:01.209: E/AndroidRuntime(1080): at java.lang.reflect.Method.invokeNative(Native Method)
01-27 03:27:01.209: E/AndroidRuntime(1080): at java.lang.reflect.Method.invoke(Method.java:511)
01-27 03:27:01.209: E/AndroidRuntime(1080): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
01-27 03:27:01.209: E/AndroidRuntime(1080): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
01-27 03:27:01.209: E/AndroidRuntime(1080): at dalvik.system.NativeStart.main(Native Method)
What you're doing is very wasteful (any splash screen is wasteful, but using Threads like this is more so), but to fix your issue:
use interrrupt(); intead of stop();
As the docs say for stop()
Throws UnsupportedOperationException.
And to fix the duplicate issue, move the startActivity() inside the try so it looks like this:
public void run() {
try {
Thread.sleep(5000);
startActivity(new Intent(SplashActivity.this, LoginAuthenticationActivity.class));
} catch (InterruptedException e) {
e.printStackTrace();
}
finish();
}
That way when you call interrupt() all your Activity does is finish() and the duplicate startActivity() is not called.
To further explain:
Very first issue: stop() throws an exception by default, since it's an unsafe method which you're not supposed to use.
Then when you used interrupt(), you had startActivity() in the run method after the catch block. When you interrupted, startActivity() was called once in run() and once in onClick(). By moving startActivity() inside the try block to right after Thread.sleep(), when interrupt() interrupts the Thread, the rest of the try block isn't executed. This means that you now only have one startActivity() call instead of two. For more information, read up on exceptions.
Related
I'm wanting to let the user create an avatar (profile picture if you like) when they set up their user info. I've created a method for a single click/touch which would ask the user to take a picture and one for a long click which would ask the user to choose a picture from their gallery.
Below are my methods from the class file:
public void onLaunchCamera(View v) {
avatarButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
String strAvatarPrompt = "Take your picture to store as your avatar!";
Intent pictureIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(Intent.createChooser(pictureIntent, strAvatarPrompt), TAKE_AVATAR_CAMERA_REQUEST);
}
});
avatarButton.setOnLongClickListener(new View.OnLongClickListener() {
public boolean onLongClick(View v) {
String strAvatarPrompt = "Choose a picture to use as your avatar!";
Intent pickPhoto = new Intent(Intent.ACTION_PICK);
pickPhoto.setType("image/*");
startActivityForResult(Intent.createChooser(pickPhoto, strAvatarPrompt), TAKE_AVATAR_GALLERY_REQUEST);
return true;
}
});
}
And below is the XML associated with the ImageButton:
<ImageButton
android:id="#+id/ImageButton_Avatar"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:adjustViewBounds="true"
android:maxHeight="#dimen/avatar_size"
android:minHeight="#dimen/avatar_size"
android:onClick="onLaunchCamera"
android:scaleType="fitXY"
android:src="#drawable/avatar"></ImageButton>
All it does is crash when I click on the ImageButton and I have no idea why. Any ideas?
Thanks
EDIT: Adding the logcat below (Sorry about the formatting. Couldn't work out how to get it all sorted properly:
[ 04-12 18:32:50.989 5901: 5901 D/ ]
HostConnection::get() New Host Connection established 0xb8a44530, tid 5901
04-12 18:32:51.039 5901-5901/cct.mad.lab D/OpenGLRenderer: Enabling debug mode 0
04-12 18:32:55.739 5901-5901/cct.mad.lab V/RenderScript: 0xb8c53300 Launching thread(s), CPUs 2
04-12 18:32:57.389 5901-5901/cct.mad.lab D/AndroidRuntime: Shutting down VM
04-12 18:32:57.389 5901-5901/cct.mad.lab W/dalvikvm: threadid=1: thread exiting with uncaught exception (group=0xb0d2db20)
04-12 18:32:57.399 5901-5901/cct.mad.lab E/AndroidRuntime: FATAL EXCEPTION: main
Process: cct.mad.lab, PID: 5901 java.lang.IllegalStateException: Could not execute method of the activity
at android.view.View$1.onClick(View.java:3823)
at android.view.View.performClick(View.java:4438)
at android.view.View$PerformClick.run(View.java:18422)
at a android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at android.view.View$1.onClick(View.java:3818)
at android.view.View.performClick(View.java:4438)
at android.view.View$PerformClick.run(View.java:18422)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at cct.mad.lab.SettingsActivity.onLaunchCamera(SettingsActivity.java:201)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at android.view.View$1.onClick(View.java:3818)
at android.view.View.performClick(View.java:4438)
at android.view.View$PerformClick.run(View.java:18422)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)
It looks like you might not have defined avatarButton, if you follow the Caused By path on the LogCat you see the bottom one is a NullPointerException.
Since I can't see the line numbers, the issue is happening on line 201--the only obvious null pointer I see in your code is avatarButton.
Based on what you want to do, you'll want to go about this a bit differently.
Remove the android:onClick="onLaunchCamera" from the XML.
in your onCreate() after you set the content view add the following:
View avatarButton = findViewById(R.id.ImageButton_Avatar);
avatarButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
String strAvatarPrompt = "Take your picture to store as your avatar!";
Intent pictureIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(Intent.createChooser(pictureIntent, strAvatarPrompt), TAKE_AVATAR_CAMERA_REQUEST);
}
});
avatarButton.setOnLongClickListener(new View.OnLongClickListener() {
public boolean onLongClick(View v) {
String strAvatarPrompt = "Choose a picture to use as your avatar!";
Intent pickPhoto = new Intent(Intent.ACTION_PICK);
pickPhoto.setType("image/*");
startActivityForResult(Intent.createChooser(pickPhoto, strAvatarPrompt), TAKE_AVATAR_GALLERY_REQUEST);
return true;
}
});
This allows you to set both a click and a longClick listener with more control. The way you had it, you were never really defining the onClick or onLongClick until you clicked on them the first time.
I have popupMenu and CheckBox. I need make write status CheckBox to boolean.
This code not working:
MenuItem fast_result;
boolean fast=false;
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
switch (id) {
case R.id.FastResult:
fast_result = item.getSubMenu().getItem(R.id.FastResult);//This is 182 line
fast_result.setChecked(!fast_result.isChecked());
fast=fast_result.isChecked();
return true;
}
}
It is errors:
FATAL EXCEPTION: main
java.lang.NullPointerException
at com.alexvsalex.HelpforMath.RootsActivity.onOptionsItemSelected(RootsActivity.java:182)
at android.app.Activity.onMenuItemSelected(Activity.java:2502)
at com.android.internal.policy.impl.PhoneWindow.onMenuItemSelected(PhoneWindow.java:950)
at com.android.internal.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:735)
at com.android.internal.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:149)
at com.android.internal.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:874)
at com.android.internal.view.menu.ListMenuPresenter.onItemClick(ListMenuPresenter.java:163)
at android.widget.AdapterView.performItemClick(AdapterView.java:292)
at android.widget.AbsListView.performItemClick(AbsListView.java:1058)
at android.widget.AbsListView$PerformClick.run(AbsListView.java:2514)
at android.widget.AbsListView$1.run(AbsListView.java:3168)
at android.os.Handler.handleCallback(Handler.java:605)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4424)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
at dalvik.system.NativeStart.main(Native Method)
What to do?
The problem is solved:
case R.id.FastResult:
fast_result = item; //There was an error
fast_result.setChecked(!fast_result.isChecked());
fast=fast_result.isChecked();
return true;
I have a simple background task to sign up, displaying a progress dialog for the user. The issue is that I believe I'm getting NullPointerException is because the second activity that's being launched in the intent is somehow being called before the dialogProgressHide(); method, even though that one is listed first in the code, therefore different context and the progress is returning null causing error.
book.saveInBackground(new SaveCallback()
{
#Override
public void done(ParseException e) {
if (e == null)
{
dialogProgressHide();
Toast.makeText(getApplicationContext(), "Your book was posted correctly!", Toast.LENGTH_LONG).show();
finish();
}
else
{
Toast.makeText(getApplicationContext(), "An error has occured: " + e + "\n" + "Please try again!", Toast.LENGTH_LONG).show();
dialogProgressHide();
}
}
});
I could be wrong but that makes sense to me, question is how would I fix this? I simply want the dialog to disappear before finishing the activity, so that it doesn't attempt to when the progress is no longer in context.
Here is dialog methods if needed:
private void dialogProgressShow() {
mDialog = new ProgressDialog(this);
mDialog.setMessage("One moment please while we post your book.");
mDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
mDialog.show();
}
private void dialogProgressHide() {
if (mDialog.isShowing())
{
mDialog.dismiss();
mDialog = null;
}
}
}
LOGCAT:
03-25 17:12:44.862: E/AndroidRuntime(16528): FATAL EXCEPTION: main
03-25 17:12:44.862: E/AndroidRuntime(16528): Process: com.jameswilson.booksale, PID: 16528
03-25 17:12:44.862: E/AndroidRuntime(16528): java.lang.NullPointerException
03-25 17:12:44.862: E/AndroidRuntime(16528): at com.jameswilson.booksale.PostBookActivity.dialogProgressHide(PostBookActivity.java:255)
03-25 17:12:44.862: E/AndroidRuntime(16528): at com.jameswilson.booksale.PostBookActivity.access$1(PostBookActivity.java:254)
03-25 17:12:44.862: E/AndroidRuntime(16528): at com.jameswilson.booksale.PostBookActivity$2$1.done(PostBookActivity.java:144)
03-25 17:12:44.862: E/AndroidRuntime(16528): at com.parse.SaveCallback.internalDone(SaveCallback.java:39)
03-25 17:12:44.862: E/AndroidRuntime(16528): at com.parse.SaveCallback.internalDone(SaveCallback.java:27)
03-25 17:12:44.862: E/AndroidRuntime(16528): at com.parse.Parse$6$1.run(Parse.java:846)
03-25 17:12:44.862: E/AndroidRuntime(16528): at android.os.Handler.handleCallback(Handler.java:733)
03-25 17:12:44.862: E/AndroidRuntime(16528): at android.os.Handler.dispatchMessage(Handler.java:95)
03-25 17:12:44.862: E/AndroidRuntime(16528): at android.os.Looper.loop(Looper.java:136)
03-25 17:12:44.862: E/AndroidRuntime(16528): at android.app.ActivityThread.main(ActivityThread.java:5017)
03-25 17:12:44.862: E/AndroidRuntime(16528): at java.lang.reflect.Method.invokeNative(Native Method)
03-25 17:12:44.862: E/AndroidRuntime(16528): at java.lang.reflect.Method.invoke(Method.java:515)
03-25 17:12:44.862: E/AndroidRuntime(16528): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
03-25 17:12:44.862: E/AndroidRuntime(16528): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
03-25 17:12:44.862: E/AndroidRuntime(16528): at dalvik.system.NativeStart.main(Native Method)
Check if your dialog reference is null before trying to dismiss it
private void dialogProgressHide() {
if (mDialog != null && mDialog.isShowing())
{
mDialog.dismiss();
mDialog = null;
}
}
i have made 2 classes YehActivity.java and h.java. On running the application i am getting an error ,Application has stopped unexpectedly.Here is the code
public class YehActivity extends Activity {
public static final int r=1;
Button b;
TextView tv;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
b.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
Intent i=new Intent(YehActivity.this,he.class);
//startActivity(i);
startActivityForResult(i, r);
}
});
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// TODO Auto-generated method stub
if(requestCode==r && resultCode==RESULT_OK){
String h=data.getStringExtra("a");
tv.setText(h);
}
}
}
where to check for null.
this is the second file
public class he extends Activity{
Button b;
EditText et;
Intent i=getIntent();
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.h);
b=(Button) findViewById(R.id.button12);
et=(EditText) findViewById(R.id.editText1);
b.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
String value=et.getText().toString().trim();
i.putExtra("a", value);
he.this.setResult(RESULT_OK, i);
finish();
}
});
}
}
and the log file is
02-11 23:31:46.408: I/Process(302): Sending signal. PID: 302 SIG: 9
02-11 23:45:04.778: D/AndroidRuntime(357): Shutting down VM
02-11 23:45:04.778: W/dalvikvm(357): threadid=1: thread exiting with uncaught exception (group=0x40015560)
02-11 23:45:04.798: E/AndroidRuntime(357): FATAL EXCEPTION: main
02-11 23:45:04.798: E/AndroidRuntime(357): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.ye/com.ye.YehActivity}: java.lang.NullPointerException
02-11 23:45:04.798: E/AndroidRuntime(357): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
02-11 23:45:04.798: E/AndroidRuntime(357): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
02-11 23:45:04.798: E/AndroidRuntime(357): at android.app.ActivityThread.access$1500(ActivityThread.java:117)
02-11 23:45:04.798: E/AndroidRuntime(357): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
02-11 23:45:04.798: E/AndroidRuntime(357): at android.os.Handler.dispatchMessage(Handler.java:99)
02-11 23:45:04.798: E/AndroidRuntime(357): at android.os.Looper.loop(Looper.java:123)
02-11 23:45:04.798: E/AndroidRuntime(357): at android.app.ActivityThread.main(ActivityThread.java:3683)
02-11 23:45:04.798: E/AndroidRuntime(357): at java.lang.reflect.Method.invokeNative(Native Method)
02-11 23:45:04.798: E/AndroidRuntime(357): at java.lang.reflect.Method.invoke(Method.java:507)
02-11 23:45:04.798: E/AndroidRuntime(357): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
02-11 23:45:04.798: E/AndroidRuntime(357): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
02-11 23:45:04.798: E/AndroidRuntime(357): at dalvik.system.NativeStart.main(Native Method)
02-11 23:45:04.798: E/AndroidRuntime(357): Caused by: java.lang.NullPointerException
02-11 23:45:04.798: E/AndroidRuntime(357): at com.ye.YehActivity.onCreate(YehActivity.java:23)
02-11 23:45:04.798: E/AndroidRuntime(357): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
02-11 23:45:04.798: E/AndroidRuntime(357): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
02-11 23:45:04.798: E/AndroidRuntime(357): ... 11 more
02-11 23:45:11.158: I/Process(357): Sending signal. PID: 357 SIG: 9
02-11 23:45:22.708: D/AndroidRuntime(374): Shutting down VM
02-11 23:45:22.708: W/dalvikvm(374): threadid=1: thread exiting with uncaught exception (group=0x40015560)
02-11 23:45:22.728: E/AndroidRuntime(374): FATAL EXCEPTION: main
02-11 23:45:22.728: E/AndroidRuntime(374): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.ye/com.ye.YehActivity}: java.lang.NullPointerException
02-11 23:45:22.728: E/AndroidRuntime(374): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
02-11 23:45:22.728: E/AndroidRuntime(374): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
02-11 23:45:22.728: E/AndroidRuntime(374): at android.app.ActivityThread.access$1500(ActivityThread.java:117)
02-11 23:45:22.728: E/AndroidRuntime(374): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
02-11 23:45:22.728: E/AndroidRuntime(374): at android.os.Handler.dispatchMessage(Handler.java:99)
02-11 23:45:22.728: E/AndroidRuntime(374): at android.os.Looper.loop(Looper.java:123)
02-11 23:45:22.728: E/AndroidRuntime(374): at android.app.ActivityThread.main(ActivityThread.java:3683)
02-11 23:45:22.728: E/AndroidRuntime(374): at java.lang.reflect.Method.invokeNative(Native Method)
02-11 23:45:22.728: E/AndroidRuntime(374): at java.lang.reflect.Method.invoke(Method.java:507)
02-11 23:45:22.728: E/AndroidRuntime(374): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
02-11 23:45:22.728: E/AndroidRuntime(374): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
02-11 23:45:22.728: E/AndroidRuntime(374): at dalvik.system.NativeStart.main(Native Method)
02-11 23:45:22.728: E/AndroidRuntime(374): Caused by: java.lang.NullPointerException
02-11 23:45:22.728: E/AndroidRuntime(374): at com.ye.YehActivity.onCreate(YehActivity.java:23)
02-11 23:45:22.728: E/AndroidRuntime(374): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
02-11 23:45:22.728: E/AndroidRuntime(374): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
02-11 23:45:22.728: E/AndroidRuntime(374): ... 11 more
02-11 23:45:25.497: I/Process(374): Sending signal. PID: 374 SIG: 9
In your
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
b.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
Intent i=new Intent(YehActivity.this,he.class);
//startActivity(i);
startActivityForResult(i, r);
}
});
}
onCreate() method you attempt to use b, but you never initialize it (I'm assuming its declared as a global variable). This means that you will run into a NullPointerException when you try to call setOnClickListener().
In your code in OnCreate() you have to declare b as button and then apply listener to that.
b=(Button) findViewById(R.id.button12);
Also check your data is null or not. If it is null than handle it properly.
Then your code runs fine.
I'm trying to start a service, but always getting NPE. What could I be doing wrong?
Even the onServiceConnected() method does not get called, why ever?
#Override
protected void onCreate(Bundle savedInstanceState) {
mServiceIntent = new Intent(this, MyService.class);
bindService(mServiceIntent, mConnection, Context.BIND_AUTO_CREATE);
//other stuff
}
usage:
private okButton(View v) {
startService(mServiceIntent);
}
result: NullPointerException!
private ServiceConnection mConnection = new ServiceConnection() {
#Override
public void onServiceConnected(ComponentName className, IBinder service) {
Log.v("service", "gets never executed!");
mDownloadService = ((LocalBinder<MyService>) service).getService();
}
#Override
public void onServiceDisconnected(ComponentName className) {
}
};
}
public class LocalBinder<S> extends Binder {
private String TAG = "LocalBinder";
private WeakReference<S> mService;
public LocalBinder(S service){
mService = new WeakReference<S>(service);
}
public S getService() {
return mService.get();
}
}
Of course I also have the service in manifest:
<service android:enabled="true" android:name=".service.MyService" />
Logcat:
06-06 23:48:20.411: W/dalvikvm(592): threadid=1: thread exiting with uncaught exception (group=0x409c01f8)
06-06 23:48:20.461: E/AndroidRuntime(592): FATAL EXCEPTION: main
06-06 23:48:20.461: E/AndroidRuntime(592): java.lang.RuntimeException: Unable to start activity ComponentInfo{MyActivity}: java.lang.NullPointerException
06-06 23:48:20.461: E/AndroidRuntime(592): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
06-06 23:48:20.461: E/AndroidRuntime(592): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
06-06 23:48:20.461: E/AndroidRuntime(592): at android.app.ActivityThread.access$600(ActivityThread.java:123)
06-06 23:48:20.461: E/AndroidRuntime(592): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
06-06 23:48:20.461: E/AndroidRuntime(592): at android.os.Handler.dispatchMessage(Handler.java:99)
06-06 23:48:20.461: E/AndroidRuntime(592): at android.os.Looper.loop(Looper.java:137)
06-06 23:48:20.461: E/AndroidRuntime(592): at android.app.ActivityThread.main(ActivityThread.java:4424)
06-06 23:48:20.461: E/AndroidRuntime(592): at java.lang.reflect.Method.invokeNative(Native Method)
06-06 23:48:20.461: E/AndroidRuntime(592): at java.lang.reflect.Method.invoke(Method.java:511)
06-06 23:48:20.461: E/AndroidRuntime(592): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
06-06 23:48:20.461: E/AndroidRuntime(592): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
06-06 23:48:20.461: E/AndroidRuntime(592): at dalvik.system.NativeStart.main(Native Method)
06-06 23:48:20.461: E/AndroidRuntime(592): Caused by: java.lang.NullPointerException
06-06 23:48:20.461: E/AndroidRuntime(592): at MyActivity.okButton(MyActivity.java:217)
06-06 23:48:20.461: E/AndroidRuntime(592): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1939)
06-06 23:48:20.461: E/AndroidRuntime(592): ... 11 more
The intent seems to be ok:
Log.v("service", String.valueOf(mServiceIntent == null)); //false
Your stack trace clearly shows the NullPointerException happening in okButton(), and according to the code you posted, the only line in that function is
startService(mServiceIntent);
So clearly mServiceIntent is null at this point, despite being set in onCreate().
Do you have any other lines where you set mServiceIntent?
Or do you have a constructor in which you call okButton()? A constructor is the only thing I can think of that would run before onCreate(). That would also explain why onServiceConnected() is never run despite the call to bindService() in onCreate().
This code is not proper Java syntax, as the method definition has no return type :
private okButton(View v) {
startService(mServiceIntent);
}
You need something like:
private void okButton(View v) {
startService(mServiceIntent);
}
It looks to me from the stack trace that the okButton() method is being called during the creation of the MyActivity instance before the onCreate() method is called and of course at that time mService will be null.
Post more code or correct the code you've posted so that it actually matches what you are using.