Java多线程系列（3）
中断Thread的方法：（by Johnny Deng）
1）标记法：通过线程不断判断标记的条件是否满足来决定线程是否退出。这种方法可能会出现中断的延迟。即当前线程如果处于bloking状态，可能无法读取条件。这种方法的例子如下：
包含两个类，一个线程类，一个控制类。
/*-**************************************************************/
*
* Package Name: seibuaa.concurrency.series3
* File Name; StopbyFlag.java
* Description :
* Author : DengXiong
* Copyright : SEI BUAA
* Date : 2006-10-20
*
/*-**************************************************************/
package seibuaa.concurrency.series3;
public class StopbyFlag extends Thread {
private volatile boolean finished = false;
public void run(){
while (!finished){
try {
sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
doSomething();
}
}
public void doSomething(){
System.out.println("Do something!");
}
public void setFinished(boolean flag){
finished = flag;
}
}
/*-**************************************************************/
*
* Package Name: seibuaa.concurrency.series3
* File Name; SwingTester.java
* Description :
* Author : DengXiong
* Copyright : SEI BUAA
* Date : 2006-10-20
*
/*-**************************************************************/
package seibuaa.concurrency.series3;
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class SwingTester extends JFrame {
/**
* @param args
*/
public static void main(String[] args) {
SwingTester tester = new SwingTester();
tester.show();
}
public SwingTester(){
this.initComponents();
}
private void initComponents(){
JPanel p = new JPanel();
setBounds(100, 100, 400, 400);
add(p, BorderLayout.SOUTH);
stopButton = new JButton();
stopButton.setText("Stop");
startButton = new JButton();
startButton.setText("Start");
p.add(startButton);
p.add(stopButton);
addWindowListener( new WindowAdapter() {
public void windowClosed( WindowEvent e ) {
if (worker != null){
worker.setFinished(true);
}
System.exit(0);
}
});
setDefaultCloseOperation( DISPOSE_ON_CLOSE );
stopButton.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e) {
startButton.setEnabled(true);
stopButton.setEnabled(false);
worker.setFinished(true);
try {
Thread.sleep(1000);
} catch (InterruptedException e1) {
e1.printStackTrace();
}
worker = null;
}
});
startButton.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e) {
startButton.setEnabled(false);
stopButton.setEnabled(true);
if (worker == null){
worker = new StopbyFlag();
}
worker.setFinished(false);
worker.start();
}
});
}
private JButton stopButton;
private JButton startButton;
private StopbyFlag worker;
}
2）中断线程的方法：即调用interrupt（）方法。这种方法会立即终断线程。不论它是否存在bloking的状态（如果存在，立即被唤醒）。
例子如下：
两个类，同上。
/*-**************************************************************/
*
* Package Name: seibuaa.concurrency.series3
* File Name; StopByInterruption.java
* Description :
* Author : DengXiong
* Copyright : SEI BUAA
* Date : 2006-10-20
*
/*-**************************************************************/
package seibuaa.concurrency.series3;
public class StopByInterruption extends Thread{
private volatile boolean finished = false;
public void run(){
while (!isInterrupted()){
try {
sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
doSomething();
}
}
public void doSomething(){
System.out.println("Do something!");
}
}
/*-**************************************************************/
*
* Package Name: seibuaa.concurrency.series3
* File Name; SwingTesterbyInterruption.java
* Description :
* Author : DengXiong
* Copyright : SEI BUAA
* Date : 2006-10-20
*
/*-**************************************************************/
package seibuaa.concurrency.series3;
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class SwingTesterbyInterruption extends JFrame{
/**
* @param args
*/
public static void main(String[] args) {
SwingTester tester = new SwingTester();
tester.show();
}
public SwingTesterbyInterruption(){
this.initComponents();
}
private void initComponents(){
JPanel p = new JPanel();
setBounds(100, 100, 400, 400);
add(p, BorderLayout.SOUTH);
stopButton = new JButton();
stopButton.setText("Stop");
startButton = new JButton();
startButton.setText("Start");
p.add(startButton);
p.add(stopButton);
addWindowListener( new WindowAdapter() {
public void windowClosed( WindowEvent e ) {
System.exit(0);
}
});
setDefaultCloseOperation( DISPOSE_ON_CLOSE );
stopButton.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e) {
startButton.setEnabled(true);
stopButton.setEnabled(false);
worker.interrupt();
worker = null;
}
});
startButton.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e) {
startButton.setEnabled(false);
stopButton.setEnabled(true);
if (worker == null){
worker = new StopByInterruption();
}
worker.start();
}
});
}
private JButton stopButton;
private JButton startButton;
private StopByInterruption worker;
}