需要产生很多线程。每个线程都执行一样的任务，比如调用某种资源。不过不是每个线程都能顺利执行至结束的，所以没有成功的线程我想把它放到一个队列Queue里(比如用linkedlist来实现)，然后按照固定的时间，比如每5秒钟后，从队列里拿出最前面的那个线程再去执行当时失败的任务。具体如何做才能实现这个过程那？开始想到需要把失败的线程暂停，然后把线程对象放到队列里，等队列中前面的都执行完了，再重新激活这个线程再去尝试执行原来的任务。可是发现线程的suspend等都不能用。那我可以在线程的RUN部分的代码里，如果发现执行失败，就在退出线程代码前加上 queue.addLast(this)么？这样能把这个线程对象加到队列里来么，等到再取出来时，会执行一样的功能？或者有更好的解决方案？谢谢！
import java.awt.AWTEvent;
import java.awt.Container;
import java.awt.EventQueue;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;public class EventQueuePanel extends JPanel implements ActionListener {
EventQueuePanel() {
JButton button = new JButton("Draw line");
add(button);
button.addActionListener(this);
} public void actionPerformed(ActionEvent evt) {
Graphics g = getGraphics(); displayPrompt(g, "Click to chooose the first point");
Point p = getClick();
g.drawOval(p.x - 2, p.y - 2, 4, 4);
displayPrompt(g, "Click to choose the second point");
Point q = getClick();
g.drawOval(q.x - 2, q.y - 2, 4, 4);
g.drawLine(p.x, p.y, q.x, q.y);
displayPrompt(g, "Done! Press button the start again.");
g.dispose();
} public void displayPrompt(Graphics g, String s) {
y += 20;
g.drawString(s, 0, y);
} public Point getClick() {
EventQueue eq = Toolkit.getDefaultToolkit().getSystemEventQueue();
while (true) {
try {
AWTEvent evt = eq.getNextEvent();
if (evt.getID() == MouseEvent.MOUSE_PRESSED) {
MouseEvent mevt = (MouseEvent) evt;
Point p = mevt.getPoint();
Point top = getRootPane().getLocation();
p.x -= top.x;
p.y -= top.y;
return p;
}
} catch (InterruptedException e) {
}
}
} private int y = 60;
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setTitle("EventQueueTest");
frame.setSize(300, 200);
frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
}); Container contentPane = frame.getContentPane();
contentPane.add(new EventQueuePanel()); frame.show();
}}
public class Queue {
private int maxSize; private long[] queArray; private int front; private int rear; private int nItems; public Queue(int s) {
maxSize = s;
queArray = new long[maxSize];
front = 0;
rear = -1;
nItems = 0;
} // put item at end of a queue
public void insert(long j) {
if (rear == maxSize - 1) // deal with wraparound
rear = -1;
queArray[++rear] = j; // increment rear and insert
nItems++;
} // take item from front of queue
public long remove() {
long temp = queArray[front++]; // get value and incr front
if (front == maxSize) // deal with wraparound
front = 0;
nItems--; // one less item
return temp;
} public long peekFront() {
return queArray[front];
} public boolean isEmpty() {
return (nItems == 0);
} public boolean isFull() {
return (nItems == maxSize);
} public int size() {
return nItems;
} public static void main(String[] args) {
Queue theQueue = new Queue(5); // queue holds 5 items theQueue.insert(10);
theQueue.insert(20);
theQueue.insert(30);
theQueue.insert(40); theQueue.remove();
theQueue.remove();
theQueue.remove(); theQueue.insert(50);
theQueue.insert(60); // (wraps around)
theQueue.insert(70);
theQueue.insert(80); while (!theQueue.isEmpty()) {
long n = theQueue.remove(); // (40, 50, 60, 70, 80)
System.out.print(n);
System.out.print(" ");
}
System.out.println("");
}
}
如果返回了，你对这个线程再调用.start()也是没有的，线程不会再次被启动。
public static void main(String args[]) {
SimpleOne so = new SimpleOne("bzwm");
ThreadImpOne tio = new ThreadImpOne(so);
new Thread(tio).start();
}
}class SimpleOne {
private transient int count = 0; private String name = null; public SimpleOne() {
} public SimpleOne(String n) {
setName(n);
} public int getCount() {
return count;
} public void setCount(int count) {
this.count = count;
} public String getName() {
return name;
} public void setName(String name) {
this.name = name;
} public void test() throws Exception {
//这里模拟任务失败，即第一次执行时失败。
if (count == 0) {
count++;
throw new Exception();
} else {
System.out.println("hello " + name);
}
}
}class ThreadImpOne implements Runnable { SimpleOne so = null; public ThreadImpOne(SimpleOne s) {
so = s;
} public void run() {
try {
//如果test方法抛出异常，则认为任务失败了。
so.test();
} catch (Exception e) {
try {
synchronized (so) {
so.wait(3000);
}
//这里继续执行run(),直到可以成功，但在失败的时候，并没有让run方法返回
run();
} catch (InterruptedException e1) { }
}
}
}