EventQueue事件

         当在其Swing线程中执行费时的业务处理时，如果在Swing线程中执行耗时的业务逻辑，例如数据库查询，文件操作在Swing线程中执行，将会导致程序界面的阻塞。

为解决上述问题，我们必须将费时的业务逻辑放在其他线程中执行，这样就不会阻塞SwingUI线程，不会使界面死锁。因此，我们必须了解Swing的事件处理机制是由EventQueue事件处理线程来控制的。

       EventQueue是一个与平台无关的类，它将来自底层类和受信任的应用程序类的事件列入队列。

1.下面一个未使用EventQueue的Swing线程添加选项:

import java.awt.*;
import java.awt.event.*;
import java.util.Vector;
import javax.swing.*;
public class SwingSingleThreadDemo extends JFrame {
	private ButtonGroup buttonGroup = new ButtonGroup();	// 按钮组
	private JList list;										// 列表组件
	private Vector listData=new Vector();					// 列表数据
	/**
	 * Launch the application
	 * @param args
	 */
	public static void main(String args[]) {
	     <span style="font-family: Arial, Helvetica, sans-serif;">SwingSingleThreadDemo frame = new SwingSingleThreadDemo();</span>
	}
	
	/**
	 * Create the frame
	 */
	public SwingSingleThreadDemo() {
		super();
		setBounds(100, 100, 236, 204); // 设置窗体大小位置
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		final JScrollPane scrollPane = new JScrollPane(); // 创建高度面板
		getContentPane().add(scrollPane, BorderLayout.CENTER);
		list = new JList(); // 创建列表组件
		scrollPane.setViewportView(list); // 滚动面板控制列表
		final JPanel buttonPanel = new JPanel(); // 创建按钮面板
		getContentPane().add(buttonPanel, BorderLayout.SOUTH);
		final JButton button = new JButton();			// 创建按钮
		button.addActionListener(new ActionListener() {
			public void actionPerformed(final ActionEvent e) {
				do_button_actionPerformed(e);			// 调用按钮事件处理方法
			}
		});
		button.setText("添加列表选项");					// 设置按钮名称
		buttonPanel.add(button);						// 添加按钮到面板
		final JPanel panel = new JPanel();				// 创建单选按钮面板
		panel.setLayout(new GridLayout(0, 1));			// 使用网格布局
		getContentPane().add(panel, BorderLayout.EAST);
		final JRadioButton radioButton_1 = new JRadioButton();	// 创建单选按钮1
		buttonGroup.add(radioButton_1);
		radioButton_1.setText("单选1");
		radioButton_1.setSelected(true);
		panel.add(radioButton_1);
		final JRadioButton radioButton_2 = new JRadioButton();	// 创建单选按钮2
		buttonGroup.add(radioButton_2);
		radioButton_2.setText("单选2");
		panel.add(radioButton_2);
		final JRadioButton radioButton_3 = new JRadioButton();	// 创建单选按钮3
		buttonGroup.add(radioButton_3);
		radioButton_3.setText("单选3");
		panel.add(radioButton_3);
		final JRadioButton radioButton_4 = new JRadioButton();	// 创建单选按钮4
		buttonGroup.add(radioButton_4);
		radioButton_4.setText("单选4");
		panel.add(radioButton_4);
		setVisible(true);										// 显示窗体
	}
	
	/**
	 * 这是<b>添加列表选项</b>按钮的事件处理方法
	 * @param e 事件对象
	 */
	protected void do_button_actionPerformed(final ActionEvent e) {
		try {
			for (int i = 0; i < 10; i++) {
				listData.add("选项"+listData.size());
				list.setListData(listData);
				Thread.sleep(1000); 							// 阻塞UI线程1秒
			}
		} catch (InterruptedException e1) {
			e1.printStackTrace();
		}
	}
}

2.使用EventQueue的方法，添加一个线程处理费时的业务逻辑:

package Chapter11;

import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.GridLayout;
import java.awt.ScrollPane;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Vector;

import javax.swing.ButtonGroup;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.JScrollPane;

public class Demo7 extends JFrame{

	//在Swing线程中执行业务处理
	private JList list;
	private ButtonGroup buttonGroup = new ButtonGroup();
	private Vector listData = new Vector();
	public Demo7(){
		setTitle("Swing中执行业务处理");
		setBounds(100, 100, 236, 204);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		final JScrollPane scrollPane = new JScrollPane();
		getContentPane().add(scrollPane,BorderLayout.CENTER);
		
		list = new JList();
		scrollPane.setViewportView(list);
		final JPanel buttonPanel = new JPanel();
		getContentPane().add(buttonPanel,BorderLayout.SOUTH);
		
		final JButton button = new JButton("添加列表选项");
		button.addActionListener(new ActionListener() {
			
			@Override
			public void actionPerformed(ActionEvent e) {
				do_button_actionPerformed(e);
			}
		});	
		buttonPanel.add(button);
		
		final JPanel panel = new JPanel();//创建单选按钮面板
		panel.setLayout(new GridLayout(0, 1));
		getContentPane().add(panel,BorderLayout.EAST);
		
		JRadioButton radioButton_1 = new JRadioButton("单选1");
		radioButton_1.setSelected(true);//默认选中
		JRadioButton radioButton_2 = new JRadioButton("单选2");
		JRadioButton radioButton_3 = new JRadioButton("单选3");
		JRadioButton radioButton_4 = new JRadioButton("单选4");
		buttonGroup.add(radioButton_1);
		buttonGroup.add(radioButton_2);
		buttonGroup.add(radioButton_3);
		buttonGroup.add(radioButton_4);
		
		panel.add(radioButton_1);
		panel.add(radioButton_2);
		panel.add(radioButton_3);
		panel.add(radioButton_4);	
	}
	protected void do_button_actionPerformed(ActionEvent e) {//一点击按钮，自动添加数据了
		new Thread(){//开辟一个新的线程执行费时业务
			public void run(){
				for(int i=0;i<10;i++){
					Runnable runnable = new Runnable() {
						
						@Override
						public void run() {
							listData.add("选项"+listData.size());
							list.setListData(listData);
						}
					};
					EventQueue.invokeLater(runnable);//在时间队列中执行Runnable对象
					try {
						Thread.sleep(1000);
					} catch (InterruptedException e1) {
						// TODO Auto-generated catch block
						e1.printStackTrace();
					}
				}
			}
		}.start();
	}
	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			
			@Override
			public void run() {
				Demo7 demo = new Demo7();
				demo.setVisible(true);
			}
		});
	}
}