Sometimes it is necessary to display progress and result updates in workthreads on the interface.

 

Principle: Do not update controls directly in workthreads

 

Reason: The method of interface control is generally thread insecure, and the operation of interface in worker thread is generally insecure.

 

Solution: Create an event by yourself and insert it into the event loop

SwingUtilities.invokeLater(new Runnable()
		{

			@Override
			public void run()
                {
			    MyFrame.textField.setText(progress);		
				}
			
		});

In the event loop, an event is fetched and found to be a custom event handler, so the Runnable callback method for the custom event is executed.

code

package my;

import javax.swing.SwingUtilities;

public class ButtonThread extends Thread
{

	
	
	@Override
	public void run() 
	{
		try 
		{
			updateUI("I");
			Thread.sleep(1000*2);
			
			updateUI("love");
			Thread.sleep(1000*2);
			
			updateUI("you");
			Thread.sleep(1000*2);
		} 
		catch (InterruptedException e) 
		{
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	
	//Thread Scheduling
	private void updateUI(String progress)
	{
		SwingUtilities.invokeLater(new Runnable()
				{

					@Override
					public void run() {
						MyFrame.textField.setText(progress);
						
					}
			
				});
	}
}

 

package my;

import java.awt.FlowLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class MyFrame extends JFrame
{
	public static JTextField textField=new JTextField(10);
	public static JButton button=new JButton("Determine");
	
	public MyFrame(String title)
	{
		super(title);
		
		//panel
		JPanel root=new JPanel();
		this.setContentPane(root);
		root.setLayout(new FlowLayout());
		

		
		root.add(textField);
		root.add(button);
		
		button.addMouseListener(new MouseAdapter() {

			@Override
			public void mouseClicked(MouseEvent e) {
				onButton();
			}
			
		});
	}
	
	private void onButton()
	{
		ButtonThread th=new ButtonThread();
		th.start();
	}
}
	

package my;
 
import java.awt.Container;
import java.awt.FlowLayout;
 
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
 
public class MyDemo
{
	private static void createGUI()
	{
		// JFrame refers to a window whose parameters are the title of the window.
		JFrame frame = new MyFrame("Demo");
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		
				// Set other parameters of the window, such as window size
		frame.setSize(500, 300);
		
		// Display window
		frame.setVisible(true);
	}
	
	public static void main(String[] args)
	{

		javax.swing.SwingUtilities.invokeLater(new Runnable() {
			public void run()
			{
				createGUI();
			}
		});
 
	}
}