java停止线程和在哪里使用锁
我的问题是在哪里使用这些线程上的锁。当我让我的圈子相互竞争时，当一个人到达终点时，程序应该停止并宣布获胜。相反，它完成了所有的圆到终点线，我相信这是因为它们都共享相同的锁，甚至可能是资源
这是我的三门课。任何帮助都将不胜感激
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JButton;
import java.awt.GridLayout;
public class HorsePanel extends JFrame {
private JPanel panel;
private JButton reset;
private JButton quit;
private JButton run;
private ActionListener listener;
public static final int FRAME_WIDTH = 500;
public static final int FRAME_HEIGHT = 400;
private TrackPane trackPane;
public HorsePanel(TrackPane t) {
trackPane = t;
createPanel();
createRunRace();
createQuit();
setSize(FRAME_WIDTH, FRAME_HEIGHT);
}
public void createRunRace() {
class RunRace implements ActionListener {
public void actionPerformed(ActionEvent rightEvent) {
run.setEnabled(false);
trackPane.start();
}
}
ActionListener a = new RunRace();
this.run.addActionListener(a);
}
public void createQuit() {
class QuitRace implements ActionListener {
public void actionPerformed(ActionEvent rightEvent) {
System.exit(0);
}
}
ActionListener b = new QuitRace();
this.quit.addActionListener(b);
}
public void createReset() {
class ResetRace implements ActionListener {
public void actionPerformed(ActionEvent rightEvent) {
//trackPane.resetCoordinates;
run.setEnabled(true);
}
}
ActionListener c = new ResetRace();
this.reset.addActionListener(c);
}
public void createPanel() {
panel = new JPanel(new BorderLayout());
trackPane = new TrackPane();
this.run = new JButton("Run Race");
this.quit = new JButton("Quit");
this.reset = new JButton("Reset");
JPanel topPanel = new JPanel();
topPanel.setLayout(new GridLayout(1, 3));
topPanel.add(run);
topPanel.add(reset);
topPanel.add(quit);
panel.add(topPanel, BorderLayout.NORTH);
panel.add(trackPane, BorderLayout.CENTER);
add(panel);
}
}
import javax.swing.JFrame;
public class HorseTester {
public static TrackPane t = new TrackPane();
public static void main(String[] args) {
new HorseTester();
}
public HorseTester() {
JFrame frame = new HorsePanel(t);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
}
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
public class HorseThread implements Runnable {
public static final int X_START = 10;
public static final int Y_START = 20;
private boolean RUNNING = true;
public int FINISH_LINE = 450;
private Horse horse;
private int xpos, ypos;
private TrackPane track;
public JFrame frame = new JFrame();
public int id;
public HorseThread(TrackPane track, int offset) {
xpos = X_START;
id = offset;
// Spaces the horses apart
ypos = Y_START * offset * 3;
horse = new Horse(xpos, ypos);
this.track = track;
}
public void paint(Graphics g) {
Graphics2D g2 = (Graphics2D) g;
horse.draw(g2);
}
/**
* Run method that thread executes and makes horses go across the screen
* racing.
*/
public void run() {
while (RUNNING) {
//varying the x position movement
horse.setX(xpos += (int) (Math.random() * 10 + 1), id);
// Sleeping the thread
track.repaint();
try {
Thread.sleep(100);
} catch (InterruptedException e) {
e.printStackTrace();
}
if (xpos >= FINISH_LINE) {
RUNNING = false;
}
}
}
}
public class Horse {
private int xTop, xStart;
private int yTop, yStart;
public static final int RING_WIDTH = 20, FINISH_LINE=450;
public JFrame frame = new JFrame();
public Lock lockThing = new ReentrantLock();
public Horse(int x, int y) {
xTop = x;
yTop = y;
xStart = x;
yStart = y;
}
public void setX(int dx, int id) {
try{
lockThing.lock();
xTop=dx;
if (dx >= FINISH_LINE){
JOptionPane.showMessageDialog(frame, id + " Won");
}
}finally{ lockThing.unlock();}
}
public void draw(Graphics2D g2) {
Ellipse2D.Double horse = new Ellipse2D.Double(xTop, yTop, RING_WIDTH,
RING_WIDTH);
g2.setColor(Color.RED);
g2.fill(horse);
g2.setColor(Color.BLUE);
g2.draw(horse);
}
}
public class TrackPane extends JPanel {
private static final int NUM_OF_HORSES = 5;
private ArrayList<HorseThread> horses = new ArrayList<HorseThread>();
private ArrayList<Thread> threads = new ArrayList<Thread>(25);
public TrackPane() {
setBackground(Color.WHITE);
reset();
}
public void reset() {
// Should dispose of any running threads...
horses.clear();
// Allocating the memory for horses
for (int i = 0; i < NUM_OF_HORSES; i++) {
horses.add(new HorseThread(this, i + 1));
}
}
public void start() {
// Should dispose of any running threads...
threads.clear();
for (int i = 0; i < horses.size(); i++) {
Thread thread = new Thread(horses.get(i));
thread.start();
threads.add(thread);
}
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
for (HorseThread horse : horses) {
horse.paint(g);
}
}
}
# 1 楼答案
您需要在线程之间共享运行变量
最快的方法（但不是最好的方法）是将其更改为静态：
更合适、更幸运的方法是创建一个组件，该组件将在线程之间共享，并负责同步。 另一个乱七八糟的是弹出窗口：
这会阻止一个线程，直到有人关闭它们，这会阻止你的线程将RUNNING设置为false。 将此逻辑移动到运行HorseThread方法，并将其从Horse类的setX方法中删除：