How can I show progress bar using Swingworker? - java

This is my code snippet. On the click of button it executes the loading program in the background, but I am unable to fetch the details of the task in the progress bar. Can anyone please tell me what am I missing here?
The point is I don't want to include all the insertion code inside my doInBackground method.
public class ProgressBarDemo extends JPanel
implements ActionListener,
PropertyChangeListener {
private JProgressBar progressBar;
private JButton startButton;
private JTextArea taskOutput;
private Task task;
class Task extends SwingWorker<Void, Integer> {
#Override
protected void process(List<Integer> arg0) {
// TODO Auto-generated method stub
super.process(arg0);
for(int k:arg0)
System.out.println("arg is "+k);
setProgress(arg0.size()-1);
}
/*
* Main task. Executed in background thread.
*/
#Override
public Void doInBackground() throws Exception {
Random random = new Random();
int progress = 0;
//Initialize progress property.
setProgress(0);
Thread.sleep(100);
new LoadUnderwritingData().filesinfolder("D:\\files to upload\\");
System.out.println("records inserted are "+LoadData.records_count_inserted);
publish(LoadData.records_count_inserted);
/*
* while (progress < 100) { //Sleep for up to one second. try {
* Thread.sleep(random.nextInt(1000)); } catch (InterruptedException ignore) {}
* //Make random progress. progress += random.nextInt(10);
* setProgress(Math.min(progress, 100)); }
*/
return null;
}
/*
* Executed in event dispatching thread
*/
#Override
public void done() {
Toolkit.getDefaultToolkit().beep();
startButton.setEnabled(true);
setCursor(null); //turn off the wait cursor
taskOutput.append("Done!\n");
}
}

I see you aren't calling progressBar.setValue(progress);.
Also you'd need to call publish(currentInsertCount); after each inserted element.
In the process method you'd do:
// assuming you are passing the current insert count to publish()
for (int k : arg0){
System.out.println("arg is " + k);
progressBar.setValue(k);
}
However from what you posted now it is not really clear where processing even occurs.
Is it this line:
new LoadUnderwritingData().filesinfolder("D:\\files to upload\\");
If it is then you would have to pass some Callback to the filesinfolder("..."), so that it can update the progress.
Note: It might be easier to just do it in a plain new Thread instead of using the SwingWorker.
How I would do it with a plain Thread:
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.FileFilter;
import java.nio.file.Files;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JProgressBar;
import javax.swing.JTextArea;
import javax.swing.SwingUtilities;
public class ProgressBarDemo extends JPanel implements ActionListener {
private JProgressBar progressBar;
private JButton startButton;
private JTextArea taskOutput;
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> {
JFrame frame = new JFrame("ProgressBarDemo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setPreferredSize(new Dimension(500, 500));
frame.add(new ProgressBarDemo());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
});
}
public ProgressBarDemo() {
progressBar = new JProgressBar(0, 100);
startButton = new JButton(">");
taskOutput = new JTextArea();
startButton.addActionListener(this);
setLayout(new BorderLayout());
add(startButton, BorderLayout.NORTH);
add(taskOutput, BorderLayout.CENTER);
add(progressBar, BorderLayout.SOUTH);
progressBar.setVisible(false);
}
// If you don't care about a small chance of the UI not updating properly then you can perform the updates directly instead of calling invokeLater.
// If you are compiling below Java 1.8, you need to convert Lambda expression to a Runnable and make the directory parameter final.
public void upload(File directory) {
// No need for invokeLater here because this is called within the AWT Event Handling
startButton.setEnabled(false);
progressBar.setVisible(true);
new Thread() {
#Override
public void run() {
taskOutput.append("Discovering files...\n");
// List<File> files = Arrays.asList(directory.listFiles()); //
// if you want to process both files and directories, but only
// in the given folder, not in any sub folders
// List<File> files = Arrays.asList(getAllFiles(directory)); //
// if you only want the files in that directory, but not in sub
// directories
List<File> files = getAllFilesRecursive(directory); // if you
// want all
// files
SwingUtilities.invokeLater(() -> {
taskOutput.append(" -> discovered " + files.size() + " files.\n");
progressBar.setMaximum(files.size());
taskOutput.append("Processing files...\n");
});
int processedCount = 0;
for (File file : files) {
try {
byte[] bytes = Files.readAllBytes(file.toPath());
// TODO: process / upload or whatever you want to do with it
} catch (Throwable e) {
// Same here, you may skip the invokeLater
SwingUtilities.invokeLater(() -> taskOutput.append("Failed to process " + file.getName() + ": " + e.getMessage() + "\n"));
e.printStackTrace();
} finally {
processedCount++;
final int prcCont = processedCount; // not necessary if invoking directly
SwingUtilities.invokeLater(() -> progressBar.setValue(prcCont));
}
}
SwingUtilities.invokeLater(() -> {
taskOutput.append(" -> done.\n");
startButton.setEnabled(true);
progressBar.setVisible(false);
});
}
}.start();
}
#Override
public void actionPerformed(ActionEvent e) {
upload(new File("C:\\directoryToUpload"));
}
/**
* Gets all normal files in the directory.
*/
public static File[] getAllFiles(File directory) {
return directory.listFiles(new FileFilter() {
#Override
public boolean accept(File pathname) {
return pathname.isFile();
}
});
}
/**
* Gets all normal files in the given directory and its sub directories.
*/
public static List<File> getAllFilesRecursive(File directory) {
List<File> result = new ArrayList<File>();
getAllFilesRecursive(directory, result);
return result;
}
private static void getAllFilesRecursive(File directory, List<File> addTo) {
if (directory.isFile()) {
addTo.add(directory);
} else if (directory.isDirectory()) {
File[] subFiles = directory.listFiles();
if (subFiles == null)
return;
for (File subFile : subFiles) {
getAllFilesRecursive(subFile, addTo);
}
}
}
}

Related

Synchronized copying display with jProgressBar

I wanted to monitor the progress of my file getting copied from source to destination. I have used synchronized keyword but somehow it not working as i expect it to be, my logic might be wrong. I will be glad if you help me out.
Here is my Code.
public class Download extends javax.swing.JFrame {
int val=0;
private Timer t;
private ActionListener a;
/* Creates new form Download */
public Download() {
initComponents();
jProgressBar1.setValue(val);
a = new ActionListener() {
#Override
public void actionPerformed(ActionEvent ae) {
if (jProgressBar1.getValue() < val)
jProgressBar1.setValue(jProgressBar1.getValue()+1);
else
t.stop();
}
};
}
public synchronized void copy(String source,String url)
{
try {
val+=25;
t=new Timer(200,a);
t.start();
FileInputStream fs = new FileInputStream(source);
FileOutputStream os = new FileOutputStream(url);
int b;
while ((b = fs.read()) != -1) {
os.write(b);
}
os.close();
fs.close();
} catch (Exception E) {
E.printStackTrace();
}
}
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
JFileChooser chooser = new JFileChooser();
chooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
String url = null;
int returnValue = chooser.showDialog(null, "Select");
if (returnValue == JFileChooser.APPROVE_OPTION) {
url = chooser.getSelectedFile().getPath();
} else {
dispose();
}
JOptionPane.showMessageDialog(this,"Wait for Completion");
if(CB1.isSelected()==true)
{
File f = new File(getClass().getResource("/PCycle/Ele.pdf").getFile());
String source= f.getAbsolutePath();
copy(source,(url+"\\"+CB1.getText()+".pdf"));
}
if(CB2.isSelected()==true)
{
File f = new File(getClass().getResource("/PCycle/Mech.pdf").getFile());
String source= f.getAbsolutePath();
copy(source,(url+"\\"+CB2.getText()+".pdf"));
}
if(CB3.isSelected()==true)
{
File f = new File(getClass().getResource("/PCycle/Phy.pdf").getFile());
String source= f.getAbsolutePath();
copy(source,(url+"\\"+CB3.getText()+".pdf"));
}
if(CB4.isSelected()==true)
{
File f = new File(getClass().getResource("/PCycle/Civil.pdf").getFile());
String source= f.getAbsolutePath();
copy(source,(url+"\\"+CB4.getText()+".pdf"));
}
JOptionPane.showMessageDialog(this,"Completed");
try {
jProgressBar1.setValue(100);
Thread.sleep(3000);
} catch (InterruptedException ex) {
Logger.getLogger(Download.class.getName()).log(Level.SEVERE, null, ex);
}
System.exit(0);
}
}
Here I tried to implement a logic in such a that, whenever we call "copy" method it will copy the file from one location to another and before that it should run the timer method by which the progress on the jProgressBar is displayed. But unfortunately even after using synchronized it is not displaying the progress for each file.
The problem is you are blocking Swing's Event Dispatching Thread (EDT).
Swing does all drawing when the EDT is not busy responding to events. In this case jButton1ActionPerformed is not returning until all files have been copied. So although a Timer is started during each copy() call, the timers never get a chance to expire, because jButton1ActionPerformed has never returned.
In this case, you want to use a SwingWorker to copy the files in a background thread.
When you want to start copying the files:
start the timer in the main thread
create and start the SwingWorker.
open a model dialog to block further user actions (or otherwise disable the UI)
As the timer expires, your progress bar will advance, and be drawn.
When the SwingWorker is done() (which is executed on the EDT),
stop the timer
dismiss the dialog (or re-enable the UI)
Note: Do not create or access any UI items, or create/start/stop timers, from the background worker thread. These actions must only be performed on the EDT.
Rough example, showing disabling UI element, starting SwingWorker, publishing from the worker to show progress (which file is being download), enabling UI when the worker finishes.
File copy is faked using a 3 seconds sleep.
package progress;
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.util.List;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JProgressBar;
import javax.swing.SwingUtilities;
import javax.swing.SwingWorker;
import javax.swing.Timer;
#SuppressWarnings("serial")
public class Download extends JFrame {
public static void main(String[] args) {
SwingUtilities.invokeLater(Download::new);
}
private final JButton downloadBtn = new JButton("Start Download");
private final JProgressBar progressBar = new JProgressBar();
private final Timer timer = new Timer(200, this::timerTick);
Download() {
super("Download Example");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(400, 300);
setLocationByPlatform(true);
downloadBtn.addActionListener(this::startDownload);
add(downloadBtn, BorderLayout.PAGE_START);
progressBar.setStringPainted(true);
add(progressBar, BorderLayout.PAGE_END);
setVisible(true);
}
private void startDownload(ActionEvent evt) {
downloadBtn.setEnabled(false);
timer.start();
DownloadWorker worker = new DownloadWorker("File1", "FileB", "AnotherFile");
worker.execute();
}
private void timerTick(ActionEvent evt) {
progressBar.setValue(progressBar.getValue()+2);
}
private class DownloadWorker extends SwingWorker<Void, String> {
private final String[] files;
DownloadWorker(String ...files) {
this.files = files;
progressBar.setValue(0);
}
#Override
protected Void doInBackground() throws Exception {
for(String file : files) {
publish(file);
// Copy the file
Thread.sleep(3000); // Pretend copy takes a few seconds
}
return null;
}
#Override
protected void process(List<String> chunks) {
String file = chunks.get(chunks.size()-1); // Just last published filename
progressBar.setString("Downloading "+file + " ...");
}
#Override
protected void done() {
progressBar.setString("Complete");
progressBar.setValue(100);
timer.stop();
downloadBtn.setEnabled(true); // Re-enable UI
}
}
}

timer action performs only after the thread is finished

I have a swing GUI named SpyBiteDemo, it will call another class(Parser) and do some calculations and show some data in a jtable inside this GUI(SpyBiteDemo). I have a jbutton1 and I want to when click on it to show my timer to begin like 1,2,3,4,5,....seconds
what happens is my timer is running correctly however it does not show value unless it is done with all the program that is filling the jtable which means the action it is detecting is I perform the action after jtable appears.
I am a complete newbie on Java for event listeners and I have searched timer, timer task, schedule, everything and could not understand what's wrong.I also tried while(true) and did not fix it.I also tried duration of 1000,0,everything no affects.
I tried to use action command,sleeping the thread, it did not help.here is what I did:
public class SpyBiteDemo extends javax.swing.JFrame {
/**
* Creates new form SpyBiteDemo
*/
private long startTime;
Timer timer = new Timer(0, new TimerListener());
private class TimerListener implements ActionListener {
#Override
public void actionPerformed(ActionEvent aEvt) {
long time = (System.currentTimeMillis() - startTime) / 1000;
label3.setText(time + " seconds");
}
}
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
jButton1.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
timer.start();
}
});
startTime = evt.getWhen();
String SeedUrl = jTextField1.getText();
Parser P = new Parser(this);
jTable2.setVisible(true);
}
}
it will start showing label3 value only after it is filling the jtable on my jframe.I want the timer to start from when I am clicking the button.
with trashgod's links I had come up with this example which is comepletely runnable on your machine, this works perfect except that when I the program finishes, it does not stop the timer since I don't know where to do it, I know I should do it in addPropertyChangeListener, however I do not have timer value.
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package javaapplication7;
import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.beans.PropertyChangeEvent;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.util.List;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JProgressBar;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingWorker;
import javax.swing.Timer;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableModel;
/**
* #see http://stackoverflow.com/a/25526869/230513
*/
public class DisplayLog {
private static final String NAME = "C:\\wamp\\bin\\mysql\\mysql5.6.17\\bin\\scosche.sql";
private static class LogWorker extends SwingWorker<TableModel, String> {
private final File file;
private final DefaultTableModel model;
private LogWorker(File file, DefaultTableModel model) {
this.file = file;
this.model = model;
model.setColumnIdentifiers(new Object[]{file.getAbsolutePath()});
}
#Override
protected TableModel doInBackground() throws Exception {
BufferedReader br = new BufferedReader(new FileReader(file));
String s;
while ((s = br.readLine()) != null) {
publish(s);
}
return model;
}
#Override
protected void process(List<String> chunks) {
for (String s : chunks) {
model.addRow(new Object[]{s});
}
}
#Override
protected void done() {}
}
private void display() {
JFrame f = new JFrame("DisplayLog");
JLabel m=new JLabel("time");
JButton jb=new JButton("run");
f.add(jb,BorderLayout.BEFORE_FIRST_LINE);
f.add(m, BorderLayout.SOUTH);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
DefaultTableModel model = new DefaultTableModel();
JTable table = new JTable(model);
JProgressBar jpb = new JProgressBar();
f.add(jpb, BorderLayout.NORTH);
f.add(new JScrollPane(table));
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
jb.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
LogWorker lw = new LogWorker(new File(NAME), model);
lw.addPropertyChangeListener((PropertyChangeEvent ev) -> {
SwingWorker.StateValue s = (SwingWorker.StateValue) ev.getNewValue();
jpb.setIndeterminate(s.equals(SwingWorker.StateValue.STARTED));
});
lw.execute();
int timeDelay = 0;
ActionListener time;
time = new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
m.setText(System.currentTimeMillis() / 1000 + "seconds");
}
};
Timer timer=new Timer(timeDelay, time);
timer.start();
if(lw.isDone())
timer.stop();
}
});
}
public static void main(String[] args) {
EventQueue.invokeLater(() -> {
new DisplayLog().display();
});
}
}
It looks like the rows that comprise your table come from the network with variable, indeterminate latency. As shown here, you can load data into your TableModel in the background of a SwingWorker. As shown here, you can calculate intermediate progress in a way that makes sense for your application and display it in a PropertyChangeListener.

Swing Progress Bar updates via Worker to EventDispatch thread

I have a JAVA6 GUI handling data import to our database. I have implemented a working JProgressBar. I understand that changes made to the GUI must be done via the event dispatch thread--which I do not think I am doing (properly/at all).
the background Worker thread, UploadWorker, is constructed by passing in the a JProgressBar created in the main program, and sets changes the value of the progress bar directly once it is finished:
// when constructed, this gets set to the main program's JProgressBar.
JProgressBar progress;
protected Void doInBackground() throws Exception {
write("<!-- Import starting at " + getCurrentTime() + " -->\n");
boolean chunked = false;
switch (importMethod) {
//do some importing
}
write("<!-- Import attempt completed at " + getCurrentTime() + "-->\n");
//here changes to the GUI are made
progress.setMaximum(0);
progress.setIndeterminate(false);
progress.setString("Finished Working");
return null;
}
This works fine, but sometimes(not always) throws me several NPE's in the std out, and users are complaining:
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at javax.swing.plaf.basic.BasicProgressBarUI.updateSizes(Unknown Source)
...etc...
Anyway, I believe there is something I need to do to get these updates executed on the proper thread, correct? How?
There are a number of ways you could do this, you could use the process method of the SwingWorker to also update the progress bar, but for me, this couples your worker to the UI, which isn't always desirable.
A better solution is to take advantage of the SwingWorkers progress and PropertyChange support, for example....
worker.addPropertyChangeListener(new PropertyChangeListener() {
#Override
public void propertyChange(PropertyChangeEvent evt) {
if ("state".equalsIgnoreCase(evt.getPropertyName())) {
SwingWorker worker = (SwingWorker) evt.getSource();
switch (worker.getState()) {
case DONE:
// Clean up here...
break;
}
} else if ("progress".equalsIgnoreCase(evt.getPropertyName())) {
// You could get the SwingWorker and use getProgress, but I'm lazy...
pb.setIndeterminate(false);
pb.setValue((Integer)evt.getNewValue());
}
}
});
worker.execute();
This means you could do this for ANY SwingWorker, so long as it was the worker was calling setProgress internally...
public static class ProgressWorker extends SwingWorker {
public static final int MAX = 1000;
#Override
protected Object doInBackground() throws Exception {
for (int index = 0; index < MAX; index++) {
Thread.sleep(250);
setProgress(Math.round((index / (float)MAX) * 100f));
}
return null;
}
}
The benefit of this is that the PropertyChange event notification is called from within the context of the of Event Dispatching Thread, making it safe to update the UI from within.
And fully runnable example...
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagLayout;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JProgressBar;
import javax.swing.SwingWorker;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class SwingWorkerProgressExample {
public static void main(String[] args) {
new SwingWorkerProgressExample();
}
public SwingWorkerProgressExample() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private JProgressBar pb;
public TestPane() {
setLayout(new GridBagLayout());
pb = new JProgressBar(0, 100);
pb.setIndeterminate(true);
add(pb);
ProgressWorker worker = new ProgressWorker();
worker.addPropertyChangeListener(new PropertyChangeListener() {
#Override
public void propertyChange(PropertyChangeEvent evt) {
if ("state".equalsIgnoreCase(evt.getPropertyName())) {
SwingWorker worker = (SwingWorker) evt.getSource();
switch (worker.getState()) {
case DONE:
// Clean up here...
break;
}
} else if ("progress".equalsIgnoreCase(evt.getPropertyName())) {
// You could get the SwingWorker and use getProgress, but I'm lazy...
System.out.println(EventQueue.isDispatchThread());
pb.setIndeterminate(false);
pb.setValue((Integer) evt.getNewValue());
}
}
});
worker.execute();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
}
public static class ProgressWorker extends SwingWorker {
public static final int MAX = 1000;
#Override
protected Object doInBackground() throws Exception {
for (int index = 0; index < MAX; index++) {
Thread.sleep(250);
setProgress(Math.round((index / (float) MAX) * 100f));
}
return null;
}
}
}
You can just create a new Runnable that performs GUI updates and invoke it in a GUI thread using SwingUtilities.invokeLater

Java SwingWorker with JDialog showing JProgressBar during JDBC network operation

I have a frame which has a button, when it is pressed a JDialog with a progress bar is shown and some data is being fetched using jdbc driver (progress bar is being updated). I needed a cancel button, so I spent some time figuring out how to connect everything. It seems to be working, but I sincerely am not sure if this way is any good. If someone has some spare time please check this code and tell me if anything is wrong with it - mainly with the whole SwingWorker and cancellation stuff.
On my pc (linux) the unsuccessful network connection attempt (someNetworkDataFetching method) takes a whole minute to timeout, do I have to worry about the SwingWorkers which are still working (waiting to connect despite being cancelled) when I try to create new ones?
Note: you need mysql jdbc driver library to run this code.
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CancellationException;
import java.util.concurrent.ExecutionException;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JProgressBar;
import javax.swing.SwingConstants;
import javax.swing.SwingUtilities;
import javax.swing.SwingWorker;
public class Test extends JFrame {
private JProgressBar progressBar = new JProgressBar();
private JLabel label = new JLabel();
private DataFetcherProgress dfp;
/**
* This class holds retrieved data.
*/
class ImportantData {
ArrayList<String> chunks = new ArrayList<>();
void addChunk(String chunk) {
// Add this data
chunks.add(chunk);
}
}
/**
* This is the JDialog which shows data retrieval progress.
*/
class DataFetcherProgress extends JDialog {
JButton cancelButton = new JButton("Cancel");
DataFetcher df;
/**
* Sets up data fetcher dialog.
*/
public DataFetcherProgress(Test owner) {
super(owner, true);
getContentPane().add(progressBar, BorderLayout.CENTER);
// This button cancels the data fetching worker.
cancelButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
df.cancel(true);
}
});
getContentPane().add(cancelButton, BorderLayout.EAST);
setLocationRelativeTo(owner);
setSize(200, 50);
df = new DataFetcher(this);
}
/**
* This executes data fetching worker.
*/
public void fetchData() {
df.execute();
}
}
class DataFetcher extends SwingWorker<ImportantData, Integer> {
DataFetcherProgress progressDialog;
public DataFetcher(DataFetcherProgress progressDialog) {
this.progressDialog = progressDialog;
}
/**
* Update the progress bar.
*/
#Override
protected void process(List<Integer> chunks) {
if (chunks.size() > 0) {
int step = chunks.get(chunks.size() - 1);
progressBar.setValue(step);
}
}
/**
* Called when worker finishes (or is cancelled).
*/
#Override
protected void done() {
System.out.println("done()");
ImportantData data = null;
try {
data = get();
} catch (InterruptedException | ExecutionException | CancellationException ex) {
System.err.println("done() exception: " + ex);
}
label.setText(data != null ? "Retrieved data!" : "Did not retrieve data.");
progressDialog.setVisible(false);
}
/**
* This pretends to do some data fetching.
*/
private String someNetworkDataFetching() throws SQLException {
DriverManager.getConnection("jdbc:mysql://1.1.1.1/db", "user", "pass");
// Retrieve data...
return "data chunk";
}
/**
* This tries to create ImportantData object.
*/
#Override
protected ImportantData doInBackground() throws Exception {
// Show the progress bar dialog.
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
dfp.setVisible(true);
}
});
ImportantData data = new ImportantData();
try {
int i = 0;
// There is a network operation here (JDBC data retrieval)
String chunk1 = someNetworkDataFetching();
if (isCancelled()) {
System.out.println("DataFetcher cancelled.");
return null;
}
data.addChunk(chunk1);
publish(++i);
// And another jdbc data operation....
String chunk2 = someNetworkDataFetching();
if (isCancelled()) {
System.out.println("DataFetcher cancelled.");
return null;
}
data.addChunk(chunk2);
publish(++i);
} catch (Exception ex) {
System.err.println("doInBackground() exception: " + ex);
return null;
}
System.out.println("doInBackground() finished");
return data;
}
}
/**
* Set up the main window.
*/
public Test() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
label.setHorizontalAlignment(SwingConstants.CENTER);
getContentPane().add(label, BorderLayout.CENTER);
// Add a button starting data fetch.
JButton retrieveButton = new JButton("Do it!");
retrieveButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
fetchData();
}
});
getContentPane().add(retrieveButton, BorderLayout.EAST);
setSize(400, 75);
setLocationRelativeTo(null);
progressBar.setMaximum(2);
}
// Shows new JDialog with a JProgressBar and calls its fetchData()
public void fetchData() {
label.setText("Retrieving data...");
dfp = new DataFetcherProgress(this);
dfp.fetchData();
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
// Use jdbc mysql driver
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException ex) {
ex.printStackTrace();
return;
}
// Show the Frame
new Test().setVisible(true);
}
});
}
}
About the only thing I might do different is not use the SwingUtilities.invokeLater in the doInBackground method to show the dialog, but maybe use a PropertyChangeListener to monitor the changes to the state property worker.
I would also use the PropertyChangeListener to monitor the changes to the progress property of the worker. Instead of using publish to indicate the progression changes I would use the setProgress method (and getProgress in the PropertyChangeListener)
For example...java swingworker thread to update main Gui
I might also consider creating the UI on a JPanel and adding it to the JDialog rather then extending directory from JDialog as it would give the oppurtunity to re-use the panel in other ways, should you wish...

how to show busy/working/loading dialog with dynamic message

i want to show modal dialog, which will block my main window and i want to control it from outside by methods showLoadingDialog(), hideLoadingDialog() and setLoadingMessage(String message) - i tried this code, but its not working - Loading dialog is visible, but without message
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JLabel;
public class LoadingExample {
private static class LoadingDialog extends JDialog {
private JLabel label = new JLabel("working");
public LoadingDialog(JFrame owner) {
super(owner, ModalityType.APPLICATION_MODAL);
setUndecorated(true);
add(label);
pack();
// move window to center of owner
int x = owner.getX()
+ (owner.getWidth() - getPreferredSize().width) / 2;
int y = owner.getY()
+ (owner.getHeight() - getPreferredSize().height) / 2;
setLocation(x, y);
repaint();
}
public void setMessage(String message) {
label.setText(message);
}
}
private static LoadingDialog loadingDialog;
public static void main(String[] args) {
final JFrame mainWindow = new JFrame("Main frame");
mainWindow.setLayout(new GridLayout(3, 3));
for (int i = 1; i <= 9; i++) {
final int workTime = i;
JButton workButton = new JButton("work for " + i + " second");
//action listener, which had to show loading dialog and countdown seconds before finish
workButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
showLoadingDialog(mainWindow);
for (int j = 0; j < workTime; j++)
try {
// ... do some work here
setLoadingMessage("remain " + (workTime - j)
+ " second(s)");
loadingDialog.repaint();
Thread.sleep(1000);
} catch (InterruptedException e1) {
e1.printStackTrace();
}
hideLoadingDialog();
}
});
mainWindow.add(workButton);
}
mainWindow.pack();
mainWindow.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mainWindow.setLocationRelativeTo(null);
mainWindow.setVisible(true);
}
public static void showLoadingDialog(JFrame owner) {
if (loadingDialog != null)
loadingDialog.dispose();
loadingDialog = new LoadingDialog(owner);
new Thread() {
#Override
public void run() {
loadingDialog.setVisible(true);
};
}.start();
}
public static void setLoadingMessage(String message) {
loadingDialog.setMessage(message);
}
public static void hideLoadingDialog() {
if (loadingDialog != null) {
loadingDialog.setVisible(false);
loadingDialog.dispose();
loadingDialog = null;
}
}
}
thanks for any suggestions
You cannot make changes to the GUI from a different thread than the dispatcher thread associated to the control you are trying to change. To do this correctly you can use SwingUtilities.InvokeLater:
new Thread() {
#Override
public void run() {
SwingUtilities.InvokeLater(new Runnable() {
public void run() {
loadingDialog.setVisible(true);
}
});
};
}.start();
I wanted to write some sample code, but before firing up my IDE I did a small search in the excellent Swing concurrency tutorial and behold, it contains exactly the sample code you are looking for. What you have is a 'task that has interim results'. So when you have intermediate results, you call the SwingWorker#publish method. In the SwingWorker#process method, you update the modal dialog with the new message you just published. The SwingWorker#done method allows you to remove the modal dialog afterwards.
But I suggest you read that whole concurrency tutorial from start to finish as your sample code shows you lack some basic Swing threading knowledge.

Categories