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GUI freeze after extracting Swipe Card data [duplicate]

Can't figure this one out. Using worker or invokeLater, the UI still freeze. After each file is downloaded, I want a JList to be updated. But the JList will only update after the tread returns.
Here is the code:
public class MyUi extends javax.swing.JFrame{
...
private void jButton2ActionPerformed(java.awt.event.ActionEvent evt){
SwingUtilities.invokeLater(new Runnable() {
//To get out of the event tread
public void run() {
dl();
}
});
}
private void dl(){
...
//ini and run the download class
Download myDownload = new Download();
myDownload.doDownload(myDlList);
}
public void updateJlist(String myString){
myModel.addElement(myString);
jList1.repaint();
}
}
public class Download{
...
public void doDownload(String[] fileName){
for(int i=0; i<fileName.length; i++){
...//download action...
//for my jList1 to be updated after each file.
MyUi.updateJlist(fileName[i]);
}
}
}
Any example would help.

invokeLater does exactly the opposite of what you expect it to do - it runs operations on the EDT, which explains the behaviour.

Download the file on a background thread and wrap just updateJlist() in a Runnable.
SwingWorker would be more reliable.
Addendum: As #mre notes, SwingWorker also makes it easy to report interim results, as shown here.

I have create a WorkerThread class which take care of Threads and GUI current/main thread . i have put my GUI application in construct() method of WorkerThread when an event fire to start XXXServer then all threads are activate and GUI work smoothlly wihout freeze. have a look.
/** * Action Event * * #see java.awt.event.ActionListener#actionPerformed(java.awt.event.ActionEvent) */
public void actionPerformed(ActionEvent ae) {
log.info("actionPerformed begin..." + ae.getActionCommand());
try {
if (ae.getActionCommand().equals(btnStart.getText())) {
final int portNumber = 9990;
try {
WorkerThread workerThread = new WorkerThread(){
public Object construct(){
log.info("Initializing the Server GUI...");
// initializing the Server
try {
xxxServer = new XXXServer(portNumber);
xxxServer.start();
btnStart.setEnabled(false);
} catch (IOException e) {
// TODO Auto-generated catch block
log.info("actionPerformed() Start button ERROR IOEXCEPTION..." + e.getMessage());
e.printStackTrace();
}
return null;
}
};workerThread.start();
} catch (Exception e) {
log.info("actionPerformed() Start button ERROR..." + e.getMessage());
e.printStackTrace();
}
} else if (ae.getActionCommand().equals(btnStop.getText())) {
log.info("Exit..." + btnStop.getText());
closeWindow();
}
} catch (Exception e) {
log
.info("Error in ServerGUI actionPerformed==="
+ e.getMessage());
}
}

Java JProgressBar does not show up by setVisible(true)

I have a method like below.
ProgressWindow is a sub class of JFrame containing JProgressBar.
addProgress() increments a value in the JProgressBar.
If I call this method from a method in another class, a frame of ProgressWindow will show up but not JProgressBar and some JLabels inside the frame. They show up after the last line (System.out.println("finish")).
If I call this method in a main method in the class containing this method, then every component (Bar, labels...) instantly shows up.
What can I do for showing the window correctly?
static void search(){
ProgressWindow window = new ProgressWindow();
window.setVisible(true);
ExecutorService execs = Executors.newFixedThreadPool(Runtime
.getRuntime().availableProcessors());
Collection<Callable<Void>> processes = new LinkedList<>();
for (int i = 0; i < 100; i++) {
processes.add(new Callable<Void>() {
#Override
public Void call() throws Exception {
progressWindow.addProgress(); // increment progress value
return null;
}
});
}
try {
execs.invokeAll(processes);
} catch (Exception e) {
e.printStackTrace();
} finally {
execs.shutdown();
}
System.out.println("finish");

The main problem is you seem to be calling search from the context of the Event Dispatching Thread.
The problem occurs because you are using execs.invokeAll which blocks until all the callables have finished running.
This means that the EDT is unable to process new events in Event Queue, including repaint events, this is why your UI is coming to a stand still...
There are a number of issues you are now going to face...
You should never update/modify a UI component from any thread other than the EDT
You should block the EDT for any reason
You seem to want to know when the search is complete, so you know need some kind of event notification...
The first thing we need is some way to be notified that the search has completed, this means you can no longer rely on search returning when the search is complete...
public interface SearchListener {
public void searchCompleted();
}
Next we need an intermeditate search method that builds the UI and ensure that the search is launched within it's own Thread...
static void search(final SearchListener listener) {
final ProgressWindow window = new ProgressWindow();
window.setVisible(true);
Thread t = new Thread(new Runnable() {
#Override
public void run() {
search(listener, window);
}
});
t.start();
}
Then we need to modify the original search method to utilise the SearchListener interface to provide notification when the search is complete...
static void search(final SearchListener listener, final ProgressWindow window){
ExecutorService execs = Executors.newFixedThreadPool(Runtime
.getRuntime().availableProcessors());
Collection<Callable<Void>> processes = new LinkedList<>();
for (int i = 0; i < 100; i++) {
processes.add(new Callable<Void>() {
#Override
public Void call() throws Exception {
// This method needs to ensure that
// what ever it does to the UI, it is done from within
// the context of the EDT!!
progressWindow.addProgress();
return null;
}
});
}
try {
execs.invokeAll(processes);
} catch (Exception e) {
e.printStackTrace();
} finally {
execs.shutdown();
}
System.out.println("finish");
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
listener.searchCompleted();
}
});
}
Now, without the source code for addProgress, I might be tempted to use
processes.add(new Callable<Void>() {
#Override
public Void call() throws Exception {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
progressWindow.addProgress();
}
});
return null;
}
});
}
Instead...
Take a look at Concurrency in Swing for more details

Sounds like you what you're wanting to do is invoke the setVisible on the Swing UI thread, you can do this with invokeAndWait or invokeLater.
So something like:
final ProgressWindow window = new ProgressWindow();
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
window.setVisible(true);
}
});

Thread in android not working as expected

I am following a guide that shows how to create a Pong game. There is a part, where I am supposed to create a Thread, and call a function that moves the ball.
This is the code I created:
package com.ozadari.pingpong;
public class PingPongGame extends Thread {
private Ball gameBall;
private PingPongView gameView;
public PingPongGame(Ball theBall,PingPongView mainView)
{
this.gameBall = theBall;
this.gameView = mainView;
}
#Override
public void run()
{
while(true)
{
this.gameBall.moveBall();
this.gameView.postInvalidate();
try
{
PingPongGame.sleep(5);
}
catch(InterruptedException e)
{
e.printStackTrace();
}
}
}}
The thread is called and working, but it doesn't print anything. I tried to cancel the infinte loop and make the loop run 100 times. After I wait a while, it prints to the screen as it should be after 100 runs, but it doesn't print anything in the middle.
What is the problem? How can I fix it?

Unsure from the code you've posted but anyway, you can use a handler and have it run once every second like so (change the time to what you want):
Handler handler = new Handler();
final Runnable r = new Runnable()
{
public void run()
{
//do your stuff here
handler.postDelayed(this, 1000);
}
};
handler.postDelayed(r, 1000);
http://developer.android.com/reference/android/os/Handler.html
You can also use a normal thread, and call start at the end.
Thread thread = new Thread()
{
#Override
public void run() {
try {
while(true) {
sleep(1000);
handler.post(r);
}
} catch (InterruptedException e) {
e.printStackTrace();
}
}
};
thread.start();

How to catch first time displaying of the WizardPage

I'm writing a little wizard for Eclipse with some pages and I need to catch the moment of the first time page displaying.
I checked constructor and createControl but they are called in the creation moment in the Wizard object (addPages).
Is there a way to get what I need? Maybe somebody knows some trick?

You can override setVisible(boolean) method in your WizardPage. So for example use something like:
private boolean initialized = false;
#Override
public void setVisible(boolean visible) {
if (!initialized && visible) {
//do something
initialized = true;
}
control.setVisible(visible);
}

You can use a IPageChangedListener or a IpageChangingListener, registered on the WizardDialog. They will be notified when the current page of the wizard changes.

I prefer to remove the listener after first painting. That way you don't need an additional boolean field and you avoid unnecessary calling paintControl and checking that boolean every time.
container.addPaintListener(new PaintListener()
{
#Override
public void paintControl(PaintEvent e)
{
doUsefulStuff();
container.removePaintListener(this);
}
});

Ok, I created a listener for a paint event and used a flag m_isFirsTime, which controlled from Wizard class:
public void createControl(Composite parent) {
Composite container = new Composite(parent, SWT.NONE);
setControl(container);
container.addPaintListener(new PaintListener() {
#Override
public void paintControl(PaintEvent arg0) {
if (m_isFirstTime) {
m_isFirstTime = false;
StartXMLParsing();
}
}
});
...
}
It is ok for me.

After controls created the async UI task executed where a long init operation can be performed. UI already created and shown when Runnable starts therefore wizard appears immediately and user can see initialization progress:
public void createControl(Composite parent) {
// create controls
getContainer().getShell().getDisplay().asyncExec(new Runnable() {
#Override
public void run() {
try {
getContainer().run(false, false, new IRunnableWithProgress() {
#Override
public void run(IProgressMonitor arg0) throws InvocationTargetException, InterruptedException {
// init and validate controls here
}
});
} catch (InvocationTargetException e) {
// handle e.getCause();
} catch (InterruptedException e) {
// nothing
}
}
});
}

Calling a Background Thread in Swing

First code:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class cos {
public static int a;
private static JLabel labeler;
// public static Runnable r1;
private JFrame frame;
/**
* Launch the application.
*/
public static void main(String[] args) {
a = 0;
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
cos window = new cos();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the application.
*/
public cos() {
initialize();
}
/**
* Initialize the contents of the frame.
*/
public void initialize() {
frame = new JFrame();
frame.setBounds(100, 100, 205, 194);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JLabel lblTime = new JLabel("Time:");
frame.getContentPane().add(lblTime, BorderLayout.WEST);
final JLabel labeler = new JLabel("");
frame.getContentPane().add(labeler, BorderLayout.CENTER);
JButton btnNewButton = new JButton("New button");
btnNewButton.addActionListener(new ActionListener() {
Runnable r1 = new Runnable() {
public void run() {
while (a <= 10) {
a = a + 1;
labeler.setText(Integer.toString(a));
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
};
public void actionPerformed(ActionEvent arg0) {
Thread threder = new Thread(r1);
threder.start();
// liczniczek bla = new liczniczek();
}
});
frame.getContentPane().add(btnNewButton, BorderLayout.SOUTH);
}
public void licznik() {
while (a < 60) {
a = a + 1;
labeler.setText(Integer.toString(a));
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
And now my question. I wanna use code like this:
Runnable r1 = new Runnable(){
public void run(){
licznik();
}
};
But that doesen't work. What i must do to separate this code ? Sorry for my bad english
Sierran.

never use Thread#sleep(int) during EDT, sure if is there only this thread then works correctly (with blockng EDT),
Runnable r1 = new Runnable(){
public void run(){
licznik();
}
};
is wrong than same as you call plain licznik();, you have to wrap that this way
Runnable r1 = new Runnable(){
public void run(){
labeler.setText(Integer.toString(a));
}
};
but again without Thread#sleep(int), you have three choises
1) change Thread to the javax.swing.Timer
2) change Thread to the Runnable#Thread, there you can delaying with Thread#sleep(int), but output to the GUI must be
Runnable r1 = new Runnable(){
public void run(){
labeler.setText(Integer.toString(a));
}
};
3) use SwingWorker, where output is in the EDT and you can use Thread#sleep(int) too
example Thread#sleep(int) during EDT
put all together
EDIT
don't use reserved words as class, method, variable, whatever Name in the Programing languages (meaning cos)
your code works by implements all three options that I post here,

What do you mean "it doesn't work"? It works for me. How are you trying to use this code, and what errors or problems are you having when you run it? Myself, I'd use a SwingWorker though and I'd set the JLabel's text via the SwingWorker's publish/process method pair. To learn more on how to use this, please see this tutorial: Concurrency in Swing
Edit
Actually, an easier way to accomplish what you want is to not use threads or Runnables directly at all but to use a Swing Timer as they're built for just this case. For more on this, please check out the Swing Timer Tutorial

I gather that you want the function licznik() to run in a separate thread. You create a Runnable, but you have to do something more to make its run() method execute. There are a couple of ways to do this:
Runnable r1 = new Runnable(){
public void run(){
licznik();
}
};
new Thread(r1).start();
or you can just subclass Thread directly:
Thread r1 = new Thread(){
public void run(){
licznik();
}
};
r1.start();

Runnable interface has no method licznik(). You can create class that implements Runnable with licznik() method.
Or if you do not need to reuse this method and use it just once, then the fastest way is to move its implementation inside new Runnable() block
Runnable r1 = new Runnable(){
public void run(){
this.licznik();
}
public void licznik(){
while (a < 60){
a = a + 1 ;
labeler.setText(Integer.toString(a));
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
};

Look on GitHub under at https://github.com/greggwon/Ham. Look at the source code in https://github.com/greggwon/Ham/blob/master/SwingUtil/src/org/wonderly/swing/ComponentUpdateThread.java to see how I've packaged this whole detail into a single class which uses anonymous inner classes to do the work. It would be possible to change this to lambdas now, but I have not used Java in several years and thus haven't made that change.
new ComponentUpdateThread( new Action[] { add, del, edit } ) {
public void setup() {
super.setup();
list.setEnabled(false);
list.clearSelection();
}
public Object construct() {
try {
Vector v = remote.getData();
Collections.sort( v );
return v;
} catch( Exception ex ) {
reportException(ex);
}
return null;
}
public void finished() {
try {
Vector v = (Vector)getValue();
if( v != null ) list.setListData(v);
} finally {
super.finished();
list.setEnabled(true);
edit.setEnabled(false);
del.setEnaled(false);
}
}
}.start();
With this style of work, you can use final values from surrounding blocks or other class visible data to control various aspects of what happens before, during and after background thread execution.
I've change this code around over the years in various ways and there are other variations of this that exist.
The arguments to the ComponentUpdateThread constructor are controls/actions to be "disabled" while the background thread is running. Other enable/disable activities can be more literally embedded into the activities in setup() and finished() (which are run in the AWT event thread) before "construct" is run in the background thread.