我通过实施Display接口创建了课程Philosopher和runnable。
我在我的项目的其他类中创建了许多线程。
如何使用方法wait()（或sleep()）暂停这些线程，然后在按下按钮时将其唤醒并继续（notify()）？
这是我的代码：
public class Display extends JPanel implements Runnable {
Image bg;
Image s0, s1, s2, s3, s4;
Image plate[] = new Image[5];
Toolkit t;
Image state1, state2;
Font font;
Chopstick chopstick;
Philosopher philosopher;
boolean isRunning = false;
public Display() {
t = Toolkit.getDefaultToolkit();
font = new Font("Tahoma", Font.PLAIN, 20);
bg = t.getImage("image//BG.png");
s0 = t.getImage("image//ts0.png");
s1 = t.getImage("image//ts1.png");
s2 = t.getImage("image//ts2.png");
s3 = t.getImage("image//ts3.png");
s4 = t.getImage("image//ts4.png");
state1 = t.getImage("image//eating.png");
state2 = t.getImage("image//thinking.png");
plate[0] = t.getImage("image//p0.png");
plate[1] = t.getImage("image//p2.png");
plate[2] = t.getImage("image//p3.png");
plate[3] = t.getImage("image//p4.png");
plate[4] = t.getImage("image//p5.png");
chopstick = new Chopstick();
philosopher = new Philosopher();
}
public void run() {
while (!isRunning) {
repaint();
try {
Thread.sleep(50);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
public boolean getStop() {
return isRunning;
}
public void setStop(boolean stop) {
isRunning = stop;
}
public void paint(Graphics g) {
super.paint(g);
// this.setBackground(Color.white);
g.drawImage(bg, 0, 0, 800, 600, null);
drawP(g);
drawP0(g);
drawP1(g);
drawP2(g);
drawP3(g);
drawP4(g);
draw0(g);
draw1(g);
draw2(g);
draw3(g);
draw4(g);
drawS0(g);
drawS1(g);
drawS2(g);
drawS3(g);
drawS4(g);
}
public void draw0(Graphics g) {
}
public void draw1(Graphics g) {
}
public void draw2(Graphics g) {
}
public void draw3(Graphics g) {
}
public void draw4(Graphics g) {
}
public void drawP0(Graphics g) {
}
public void drawP1(Graphics g) {
}
public void drawP2(Graphics g) {
}
public void drawP3(Graphics g) {
}
public void drawP4(Graphics g) {
}
public void drawP(Graphics g) {
}
//
public void drawS0(Graphics g) {
}
public void drawS1(Graphics g) {
}
public void drawS2(Graphics g) {
}
public void drawS3(Graphics g) {
}
public void drawS4(Graphics g) {
}
public void drawQuote(Graphics g) {
if (philosopher.getQuote(0) == 1) {
}
if (philosopher.getQuote(0) == 2) {
}
if (philosopher.getQuote(0) == 3) {
}
}
}
public class App {
JButton btPause, btStart;
JPanel panelButton;
JFrame f1;
Chopstick chopstick[];
Philosopher philosophers[];
final String TITLE = "Dining Pholosophers Simulator";
final ImageIcon ICON_START = new ImageIcon("image/run.png");
final ImageIcon ICON_PAUSE = new ImageIcon("image/play.png");
final ImageIcon ICON_RESUME = new ImageIcon("image/resume.png");
boolean isRunning = false;
public App() {
f1 = new JFrame();
//f1.setLayout(null);
f1.setTitle(TITLE);
f1.setSize(1120, 680);
f1.setVisible(true);
f1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f1.setLocationRelativeTo(null);
f1.setResizable(false);
// Khởi tạo 5 cây đũa
initializePos();
// Khởi tạo 5 luồng (Triết gia)
initializePhilosopher();
Display obj = new Display();
obj.setBounds(0, 0, 1040, 600);
// Luồng chính Frame cửa sổ chính
Thread t1 = new Thread(obj);
// t1.start();
// Chạy 5 luồng triết gia
Thread p1 = new Thread(philosophers[0]);
// p1.start();
Thread p2 = new Thread(philosophers[1]);
// p2.start();
Thread p3 = new Thread(philosophers[2]);
// p3.start();
Thread p4 = new Thread(philosophers[3]);
// p4.start();
Thread p5 = new Thread(philosophers[4]);
// p5.start();
// f1.add(obj0);
f1.add(obj);
//btStart = new JButton("Start...", new ImageIcon("image/pause16.png"));
btStart = new JButton("Run", ICON_START);
btPause = new JButton("Pause", ICON_PAUSE);
btPause.setEnabled(false);
// Chạy các tiến trình
btStart.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
t1.start();
p1.start();
p2.start();
p3.start();
p4.start();
p5.start();
isRunning = true;
btStart.setEnabled(false);
btPause.setEnabled(true);
}
});
// Đóng băng các tiến trình đang chạy
btPause.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
// Nếu đóng băng
if (isRunning) {
isRunning = false;
// Thay đổi trên giao diện
btPause.setText("Resume");
btPause.setIcon(ICON_RESUME);
// I want to call the method to pause those threads here
} else {
isRunning = true;
btPause.setText("Pause");
btPause.setIcon(ICON_PAUSE);
// I want to call the method to continue threads here
}
}
});
// f1.add(btStart, BorderLayout.SOUTH);
panelButton = new JPanel();
panelButton.setLayout(new FlowLayout());
panelButton.add(btStart);
panelButton.add(btPause);
f1.add(panelButton, BorderLayout.SOUTH);
f1.validate();
}
public void initializePos() {
chopstick = new Chopstick[5];
chopstick[0] = new Chopstick(0, 270, 330);
chopstick[1] = new Chopstick(1, 200, 200);
chopstick[2] = new Chopstick(2, 350, 120);
chopstick[3] = new Chopstick(3, 500, 210);
chopstick[4] = new Chopstick(4, 430, 330);
}
public void initializePhilosopher() {
philosophers = new Philosopher[5];
philosophers[0] = new Philosopher(0, chopstick[0], chopstick[4]);
philosophers[1] = new Philosopher(1, chopstick[1], chopstick[0]);
philosophers[2] = new Philosopher(2, chopstick[2], chopstick[1]);
philosophers[3] = new Philosopher(3, chopstick[3], chopstick[2]);
philosophers[4] = new Philosopher(4, chopstick[4], chopstick[3]);
}
public static void main(String args[]) {
System.out.println("Simulator is ready, click Start...\n");
new App();
}
}
任何帮助都会有很大的帮助。
答案 0 :(得分：1)
你可以告诉哲学家在run()方法的适当位置等待，然后通知他们恢复：
boolean waitRequested = false;
void requestWait() {
waitRequested = true;
}
void resume() {
synchronized(this) {
notify();
}
}
public void run() {
while( condition ) {
try {
//check if the thread should wait first, if not let it do a full iteration of the loop
if( waitRequested ) {
synchronized( this ) {
wait();
//resuming here so wait wouldn't be requested anymore
waitRequested = false;
}
}
//do whatever a philosopher does
}
catch( InterruptedException e) {
//handle exception
}
}
}
然后在对象上调用requestWait()和resume()。请注意，你只需要在对象上调用notify()，但是你必须用同步块包围它，否则你肯定会得到一个IllegalMonitorStateException，因为正在调用{{1}的线程很可能不是显示器的当前所有者。