#Service
#Slf4j
public class ScheduleService implements CommandLineRunner, ApplicationListener<ContextClosedEvent>, DisposableBean {
#Override
public void destroy() throws Exception {
try {
System.out.println("exit");
Thread.sleep(3000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
There is no problem when closing the project in IntelliJ to run the method in the Spring Boot project.
However, if the project is built into a jar file and then executed in the cmd window and then forced to close, the method does not work.
Is there a way to execute the destroy() function even if I force quit by clicking the "X" button of cmd? If you exit normally with ctrl+c, there is no problem, but users click the "X" button in cmd.
use:
log.info("exit")
and try to find it in application.log
I have a simple Java SWT app in Java so far but the weird thing is when I try to launch a messagebox/alert box upon listening to an event fired by one of my own classes, I get an error saying "Invalid thread access".
My class event is fired and heard by the main class but it is when it has to show the MessageBox that the "Invalid thread access" error appear. I am trying to show the MessageBox in a function that consist of all the other codes that will create the SWT GUIs. This is how the function looks like:
public void createContents() {
Shell shell = new Shell();
//.....all the SWT GUI codes....
MessageBox msg = new MessageBox(shell, SWT.OK);
myClass.addEventListener(new MyClassEventClassListener() {
#Override
public void myClassEventHandler(MyClassEvent e) {
msg.setText("Hello");
msg.setMessage("Event fired!");
int result = msg.open();
}
});
}
These are the auxiliary functions together in the class.
<!-- language: lang-java -->
protected static Shell shell;
public static void main(String[] args) {
MyClass new myClass = new MyClass();
try {
SWTApp window = new SWTApp();
window.open();
} catch (Exception e) {
}
public void open() {
Display display = Display.getDefault();
createContents();
shell.open();
shell.layout();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
}
The error stack trace is as follows:
Exception in thread "AWT-EventQueue-0" org.eclipse.swt.SWTException: Invalid thread access
at org.eclipse.swt.SWT.error(SWT.java:4083)
at org.eclipse.swt.SWT.error(SWT.java:3998)
at org.eclipse.swt.SWT.error(SWT.java:3969)
at org.eclipse.swt.widgets.Display.error(Display.java:1249)
at org.eclipse.swt.widgets.Display.checkDevice(Display.java:755)
at org.eclipse.swt.widgets.Display.getShells(Display.java:2171)
at org.eclipse.swt.widgets.Display.setModalDialog(Display.java:4463)
at org.eclipse.swt.widgets.MessageBox.open(MessageBox.java:200)
Any help will be great.
Thanks!
It is thrown because your listener code is called from outside the SWT Display thread. You run code on the display thread like this:
Display.getDefault().syncExec(new Runnable() {
public void run() {
// ...
}
});
or, asynchronously:
Display.getDefault().asyncExec(new Runnable() {
public void run() {
// ...
}
});
Maybe this will help you:
FAQ Why do I get an invalid thread access exception?
https://wiki.eclipse.org/FAQ_Why_do_I_get_an_invalid_thread_access_exception%3F
I have to run a few methods when Application starts, like the following:
#SpringBootApplication
public class Application implements CommandLineRunner {
private final MonitoringService monitoringService;
private final QrReaderServer qrReaderServer;
#Override
public void run(String... args) {
monitoringService.launchMonitoring();
qrReaderServer.launchServer();
}
However, only the first one is executed! And the application is started:
... Started Application in 5.21 seconds (JVM running for 6.336)
... START_MONITORING for folder: D:\results
The second one is always skipped!
If change the call order - the only the second one will be executed.
Could not find any solution for launching both at the beginning - tried #PostConstruct, ApplicationRunner, #EventListener(ApplicationReadyEvent.class)...
Looks like they are blocking each other somehow. Despite the fact that both have void type.
Monitoring launch implementation:
#Override
public void launchMonitoring() {
log.info("START_MONITORING for folder: {}", monitoringProperties.getFolder());
try {
WatchKey key;
while ((key = watchService.take()) != null) {
for (WatchEvent<?> event : key.pollEvents()) {
WatchEvent.Kind<?> kind = event.kind();
if (kind == ENTRY_CREATE) {
log.info("FILE_CREATED: {}", event.context());
// some delay for fully file upload
Thread.sleep(monitoringProperties.getFrequency());
String fullFileName = getFileName(event);
String fileName = FilenameUtils.removeExtension(fullFileName);
processResource(fullFileName, fileName);
}
}
key.reset();
}
} catch (InterruptedException e) {
log.error("interrupted exception for monitoring service", e);
} catch (IOException e) {
log.error("io exception while processing file", e);
}
}
QR Reader start (launch TCP server with Netty configuration):
#Override
public void launchServer() {
try {
ChannelFuture serverChannelFuture = serverBootstrap.bind(hostAddress).sync();
log.info("Server is STARTED : port {}", hostAddress.getPort());
serverChannel = serverChannelFuture.channel().closeFuture().sync().channel();
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
} finally {
shutdownQuietly();
}
}
How to solve this issue?
Start launchMonitoring() asynchronously.
The easiest way to do this is to enable Async by adding #EnableAsync on your Application
and then annotate launchMonitoring() with #Async
Not sure if launchServer() should also be started asynchronously.
EDIT: completed Answer
No task executor bean found for async processing: no bean of type TaskExecutor and no bean named 'taskExecutor' either
By default Spring will create a SimpleAsyncTaskExecutor, but you can provide your taskExecutor
Example:
#EnableAsync
#Configuration
public class AsyncConfig implements AsyncConfigurer {
#Override
public Executor getAsyncExecutor() {
ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
executor.set... // your custom configs
executor.initialize();
return executor;
}
...
}
Here is my code
public class MainActivity extends Activity implements GoogleApiClient.ConnectionCallbacks,GoogleApiClient.OnConnectionFailedListener {
private GoogleApiClient mGoogleApiClient;
private String TAG = "app comm";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
int code = GooglePlayServicesUtil.isGooglePlayServicesAvailable(getApplicationContext());
if (code == ConnectionResult.SUCCESS) {
Log.d(TAG, "success ");
buildGoogleApiClient();
} else {
Log.d(TAG, "fail ");
}
}
private void buildGoogleApiClient() {
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addApi(Nearby.CONNECTIONS_API).addConnectionCallbacks(this).addOnConnectionFailedListener(this).build();
}
#Override
public void onConnected(#Nullable Bundle bundle) {
Log.d(TAG,"connected");
}
#Override
public void onConnectionSuspended(int i) {
Log.d(TAG,"suspended");
}
#Override
public void onConnectionFailed(#NonNull ConnectionResult connectionResult) {
Log.d(TAG,"failed");
}
}
I am new to this
I run this program in raspberry pi 3
I have checked and internet is working.
isGoogleServicesAvailable is returning true.
but none of the override methods called. I don't know what I am missing.
Here is my log
Connected to process 8191 on device google-iot_rpi3-192.168.1.2:5555
Capturing and displaying logcat messages from application. This behavior can be disabled in the "Logcat output" section of the "Debugger" settings page.
I/zygote: Late-enabling -Xcheck:jni
W/zygote: Using default instruction set features for ARM CPU variant (generic) using conservative defaults
I/InstantRun: starting instant run server: is main process
V/first log: first raspberry log message
D/app comm: success
D/vndksupport: Loading /vendor/lib/hw/android.hardware.graphics.mapper#2.0-impl.so from current namespace instead of sphal namespace.
Looking at your code snippet, you are not calling the connect method after building it, which is what actually starts the connection and gives a callback.
When opening a new dialog, while its loading, you click couple of times on parent shell, apparently the new dialog does not display correctly.
Please see the example below:
Examples
https://i.stack.imgur.com/ZovxE.png (eclipse IDE example)
https://i.stack.imgur.com/5zVar.png
https://i.stack.imgur.com/u86b9.png
https://i.stack.imgur.com/FGaAr.png
Initially I encountered the problem in december 2014, and back then also reported by vaious in house devlopers which were using different development systems and then same problem has been reported by our several customers.
This behavior can be reproduced using following environment:
Windows Version: 7 Pro 64 Bit - 6.1.7601
Java Version: RE 1.8.0_121_b13
SWT Versions
3.8.2
4.6.2
4.7M6
I20170319-2000
I could only reproduce the problem on Windows 7 with the windows basic theme/design/style (not with classic or aero).
On windows 10 its not reproducible.
reproduce
code to reproduce
package test;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.layout.RowLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Dialog;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Text;
public class Main {
public static void main(String[] args) {
Display display = new Display();
final Shell shell = createShell(display);
createButton(shell);
shell.open();
eventLoop(display, shell);
display.dispose();
}
private static Shell createShell(Display display) {
final Shell shell = new Shell(display);
shell.setLayout(new RowLayout());
shell.setSize(500, 200);
return shell;
}
private static void createButton(final Shell shell) {
final Button openDialog = new Button(shell, SWT.PUSH);
openDialog.setText("Click here to open Dialog ...");
openDialog.addSelectionListener(new SelectionAdapter() {
public void widgetSelected(SelectionEvent e) {
TestDialog inputDialog = new TestDialog(shell);
inputDialog.open();
}
});
}
private static void eventLoop(Display display, final Shell shell) {
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
}
}
class TestDialog extends Dialog {
public TestDialog(Shell parent) {
super(parent, SWT.DIALOG_TRIM | SWT.APPLICATION_MODAL | SWT.MIN | SWT.MAX | SWT.RESIZE);
setText("Dialog");
}
public void open() {
Shell shell = new Shell(getParent(), getStyle());
shell.setText(getText());
createContents(shell);
shell.pack();
initializeBounds(shell);
shell.open();
eventLoop(shell);
}
private void createContents(final Shell shell) {
shell.setLayout(new GridLayout(2, true));
Label label = new Label(shell, SWT.NONE);
label.setText("Some Label text ...");
final Text text = new Text(shell, SWT.BORDER);
GridData data = new GridData(GridData.FILL_HORIZONTAL);
text.setLayoutData(data);
createCloseButton(shell);
/* time for the user to create the misbehavior */
try {
Thread.sleep(15000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
private void createCloseButton(final Shell shell) {
Button closeButton = new Button(shell, SWT.PUSH);
closeButton.setText("Close");
GridData data = new GridData(GridData.FILL_HORIZONTAL);
closeButton.setLayoutData(data);
closeButton.addSelectionListener(new SelectionAdapter() {
public void widgetSelected(SelectionEvent event) {
shell.close();
}
});
shell.setDefaultButton(closeButton);
}
private void initializeBounds(Shell shell) {
Rectangle bounds = shell.getBounds();
Rectangle parentBounds = getParent().getBounds();
bounds.x = parentBounds.x;
bounds.y = parentBounds.y;
shell.setBounds(bounds);
}
private void eventLoop(Shell shell) {
Display display = getParent().getDisplay();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
}
}
steps to reproduce
Start the application
it should look like: https://i.stack.imgur.com/dMJ9e.png
Click on the button.
Keep continuously clicking on right bottom corner of the parent shell (avoid hitting the new opening dialog), till mouse cursor changes to wait icon and parent shell changes its color.
it should look as following: https://i.stack.imgur.com/c1Ikp.png
Wait until the new dialog appears.
it looks likes as following: https://i.stack.imgur.com/kTDgQ.png (incorrectly displayed)
instead: https://i.stack.imgur.com/cHVjn.png (correctly displayed)
steps to reproduce done in video
https://youtu.be/7ukhloCPf0k
When you mouse hover some of the UI elements (the originally not correctly drawn), you can notice some of them to be get painted (e.g. table rows).
https://i.stack.imgur.com/kkMKn.png (before opening the dialog)
https://i.stack.imgur.com/ZXIKc.png (after opening the dialog)
https://i.stack.imgur.com/25M7S.jpg (after mouse over)
Even calling Shell.update() or Shell.redraw() after the Dialog opened does not fix it.
In Windows Performance Options -> Visual Effects -> disable "Use visual styles on windows and buttons" is the only option I found which provides a workaround,
which seems to be the same as changing the design/theme/style to classic.
https://www.sevenforums.com/tutorials/1908-visual-effects-settings-change.html (How to Change Windows Visual Effects)
In the end, I have following questions:
Is it a SWT or Windows problem?
Is there any related topic in bug entries for Windows or in Eclipse Bugzilla?
Is there someone else who experienced the same problem? please share the experience.
Is there any settings in SWT or Windows which could affect its look n feel and fix the problem?
In the end, I have following questions: Is it a SWT or Windows problem?
Neither. As others have mentioned, you certainly should not tie up the UI thread with any long-running task. That work belongs in a background thread.
In regards to using a background thread, there are several ways you could go about this depending on how you want your Dialog to behave.
One option would be to kick off the background thread and then open the dialog when the task is done. I personally don't care for this because while the task is running, a user may think that nothing is happening.
Another option would be to open the dialog but display a "Loading" message, or something to that effect to give meaningful feedback and let a user know that the application isn't frozen (like how it looks/responds in your example).
The strategy would be to:
Create the dialog
Start the long task on a background thread and register a callback
Open the dialog with a "Loading" message
When the task is complete, the dialog will be updated from the callback
If you search around a bit on using Executors, you should find some far better examples and detail on how to use them.
Here's a brief example to illustrate what that might look like:
(Note: There are definitely a few issues with this code, but for the sake of brevity and illustrating the point I opted for a slightly naive solution. Also there are Java 8-esque ways that would be a bit shorter, but again, this illustrates the idea behind using a background thread; the same concepts apply)
Given a Callable (or Runnable if you don't need a return value),
public class LongTask implements Callable<String> {
#Override
public String call() throws Exception {
Thread.sleep(15000);
return "Hello, World!";
}
}
You can use the Executors class to create a thread pool, and then an ExecutorService to submit the Callable for execution. Then, using Futures.addCallback(), you can register a callback which will execute one of two methods depending on whether the task was successful or failed.
final ExecutorService threadPool = Executors.newFixedThreadPool(1);
final ListeningExecutorService executorService = MoreExecutors.listeningDecorator(threadPool);
final ListenableFuture<String> future = executorService.submit(new LongTask());
Futures.addCallback(future, new FutureCallback(){...});
In this case I used the Google Guava implementation ListeningExecutorService which makes things a bit cleaner and simpler, in my opinion. But again, you may not even need this if you opt for a more "Java 8" approach.
As for the callback, when the task is successful, we update the Dialog with the results. If it fails, we can update it with something to indicate failure:
public static class DialogCallback implements FutureCallback<String> {
private final MyDialog dialog;
public DialogCallback(final MyDialog dialog) {
this.dialog = dialog;
}
#Override
public void onSuccess(final String result) {
dialog.getShell().getDisplay().asyncExec(new Runnable() {
#SuppressWarnings("synthetic-access")
#Override
public void run() {
dialog.setStatus(result);
}
});
}
#Override
public void onFailure(final Throwable t) {
dialog.getShell().getDisplay().asyncExec(new Runnable() {
#SuppressWarnings("synthetic-access")
#Override
public void run() {
dialog.setStatus("Failure");
}
});
}
}
In this case I opted for the Callable to return a String, thus the FutureCallback should be parameterized with String. You may want to use some other class that you created, which will work just as well.
Notice that we use the Display.asyncExec() method to ensure that the code which updates the UI runs on the UI thread, because the callback may execute on the background thread.
Like I said, there are still a few issues here, including what happens when you click the cancel button before the task completes, etc. But hopefully this helps illustrate an approach for handling long-running background tasks without blocking the UI thread.
Full example code:
public class DialogTaskExample {
private final Display display;
private final Shell shell;
private final ListeningExecutorService executorService;
public DialogTaskExample() {
display = new Display();
shell = new Shell(display);
shell.setLayout(new GridLayout());
executorService = MoreExecutors.listeningDecorator(Executors.newFixedThreadPool(1));
final Button button = new Button(shell, SWT.PUSH);
button.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, false));
button.setText("Start");
button.addSelectionListener(new SelectionAdapter() {
#SuppressWarnings("synthetic-access")
#Override
public void widgetSelected(final SelectionEvent e) {
final MyDialog dialog = new MyDialog(shell);
dialog.setBlockOnOpen(false);
dialog.open();
dialog.setStatus("Doing stuff...");
final ListenableFuture<String> future = executorService.submit(new LongTask());
Futures.addCallback(future, new DialogCallback(dialog));
}
});
}
public void run() {
shell.setSize(200, 200);
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
executorService.shutdown();
display.dispose();
}
public static void main(final String... args) {
new DialogTaskExample().run();
}
public static class DialogCallback implements FutureCallback<String> {
private final MyDialog dialog;
public DialogCallback(final MyDialog dialog) {
this.dialog = dialog;
}
#Override
public void onSuccess(final String result) {
dialog.getShell().getDisplay().asyncExec(new Runnable() {
#SuppressWarnings("synthetic-access")
#Override
public void run() {
dialog.setStatus(result);
}
});
}
#Override
public void onFailure(final Throwable t) {
dialog.getShell().getDisplay().asyncExec(new Runnable() {
#SuppressWarnings("synthetic-access")
#Override
public void run() {
dialog.setStatus("Failure");
}
});
}
}
public static class LongTask implements Callable<String> {
/**
* {#inheritDoc}
*/
#Override
public String call() throws Exception {
Thread.sleep(15000);
return "Hello, World!";
}
}
public static class MyDialog extends Dialog {
private Composite baseComposite;
private Label label;
/**
* #param parentShell
*/
protected MyDialog(final Shell parentShell) {
super(parentShell);
}
/**
* {#inheritDoc}
*/
#Override
protected Control createDialogArea(final Composite parent) {
baseComposite = (Composite) super.createDialogArea(parent);
label = new Label(baseComposite, SWT.NONE);
return baseComposite;
}
public void setStatus(final String text) {
label.setText(text);
baseComposite.layout();
}
}
}
The code seems to be straight forward, only that you are making the main Thread sleep for 15secs hence the delay. If not required remove the sleep or reduce the time for sleep to 5secs or so.