Adding copy action in windows to java app

Question

I want to get the event like crtl+c or right click copy in windows , that could do the event to java application running ,

that means if someone copies some text , that should be pasted into the java application textarea...

i have made the java application and it can accept arguments through main method.

but how to trigger event from windows to java..

Answer 1

The simplest way is to monitor changes to the Toolkit.getSystemClipboard

There are two ways to do this. You can monitor changes to the DataFlavour, but this will only help if the data flavor changes, not the content and/or you could monitor the contents of the clipboard and update your view when it's content changes...

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Toolkit;
import java.awt.datatransfer.Clipboard;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.FlavorEvent;
import java.awt.datatransfer.FlavorListener;
import java.awt.datatransfer.Transferable;
import java.awt.datatransfer.UnsupportedFlavorException;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class ClipboardMonitor {

    public static void main(String[] args) {
        new ClipboardMonitor();
    }

    public ClipboardMonitor() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        private JTextArea textArea;

        public TestPane() {
            textArea = new JTextArea(10, 10);
            setLayout(new BorderLayout());
            add(new JScrollPane(textArea));
            Toolkit.getDefaultToolkit().getSystemClipboard().addFlavorListener(new FlavorListener() {
                @Override
                public void flavorsChanged(FlavorEvent e) {
                    setText(getClipboardContents());
                }
            });
            Thread t = new Thread(new ContentsMonitor());
            t.setDaemon(true);
            t.start();
        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(200, 200);
        }

        protected String getClipboardContents() {
            String text = null;
            Clipboard clipboard = Toolkit.getDefaultToolkit().getSystemClipboard();
            if (clipboard.isDataFlavorAvailable(DataFlavor.stringFlavor)) {
                try {
                    Transferable contents = clipboard.getContents(TestPane.this);
                    text = (String) contents.getTransferData(DataFlavor.stringFlavor);
                } catch (UnsupportedFlavorException | IOException ex) {
                    ex.printStackTrace();
                }
            }
            return text;
        }

        protected void setText(final String text) {
            SwingUtilities.invokeLater(new Runnable() {
                @Override
                public void run() {
                    textArea.setText(text);
                }
            });
        }

        public class ContentsMonitor implements Runnable {

            @Override
            public void run() {
                String previous = getClipboardContents();
                while (true) {
                    try {
                        Thread.sleep(1000);
                    } catch (InterruptedException ex) {
                    }
                    String text = getClipboardContents();
                    if (text != null && !text.equals(previous)) {
                        setText(text);
                        previous = text;
                    }
                }
            }
        }
    }
}