我在下面的代码中有我的线程的骨架。 我使用了一个简单的倒计时锁存器。 我陷入了一种情况，我有线程1取决于线程2来完成。如果没有异常，则代码正常运行。 但例外的可能性更大。 如果在线程2或任何线程中发生异常，我希望所有线程都停止执行。我的独立线程甚至在异常之后继续执行。我还在线程1中使用了一个标志来检查线程2中是否发生了异常 我故意将除以零的异常作为例子来测试异常。 我无法找到解决方案。 请帮我..！
import java.util.concurrent.CountDownLatch;
public class MainThread extends Thread{
static boolean flag=false;
final static CountDownLatch latch1= new CountDownLatch(1);
final static CountDownLatch latch2= new CountDownLatch(1);
final static CountDownLatch latch3= new CountDownLatch(3);
static MainThread t1;
static MainThread t2;
static MainThread t3;
static MainThread t4;
static MainThread t5;
public static void main(String args[]){
t1 = new MainThread(){
public void run(){
System.out.println("Waiting for Thread 2");
try {
System.out.println("THis iss before the thread 2 starts its for loop.");
latch2.countDown();
t3.start();
t4.start();
t5.start();
System.out.println("waiting for thread 2 to countdown");
latch1.await();
if(flag==true){
System.out.println("successful.");
}
else{
System.out.println("error.");
}
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("All the dependencies resolved.");
System.out.println("Waiting for the remaining threads to complete their work.");
try {
latch3.await();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("All the threads have finished doing their work. Exiting now...");
}
};
Thread t2 = new MainThread(){
public void run(){
System.out.println("Before Starting for loop");
try {
System.out.println("waiting for thread 1 to countdown latch2");
latch2.await();
System.out.println("Starting for loop");
for(int i=0;i<5;i++){
System.out.println("iteration: "+i);
try {
Thread.sleep(5);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
int x=1/0;
latch1.countDown();
System.out.println("countdown by thread2 for latch 1 done.");
flag=true;
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
finally{
latch1.countDown();
}
}
};
t3 = new MainThread(){
public void run(){
System.out.println("Running Thread 3");
for(int i=0;i<10;i++){
System.out.println("iteration: "+i+ " "+t3.getName());
try {
Thread.sleep(5);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
latch3.countDown();
}
};
t4 = new MainThread(){
public void run(){
System.out.println("Running Thread 4");
for(int i=0;i<10;i++){
System.out.println("iteration: "+i+ " "+t4.getName());
try {
Thread.sleep(5);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
latch3.countDown();
}
};
t5 = new MainThread(){
public void run(){
System.out.println("Running Thread 5");
for(int i=0;i<10;i++){
System.out.println("iteration: "+i+ " "+t5.getName());
try {
Thread.sleep(5);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
latch3.countDown();
}
};
t1.start();
t2.start();
}
}
我的输出是：
Before Starting for loop
waiting for thread 1 to countdown latch2
Waiting for Thread 2
THis iss before the thread 2 starts its for loop.
Starting for loop
iteration: 0
waiting for thread 2 to countdown
Running Thread 3
iteration: 0 Thread-2
Running Thread 5
iteration: 0 Thread-4
Running Thread 4
iteration: 0 Thread-3
iteration: 1
iteration: 1 Thread-3
iteration: 1 Thread-2
iteration: 1 Thread-4
iteration: 2
iteration: 2 Thread-3
iteration: 2 Thread-2
iteration: 2 Thread-4
iteration: 3
iteration: 3 Thread-3
iteration: 3 Thread-2
iteration: 3 Thread-4
iteration: 4
iteration: 4 Thread-3
iteration: 4 Thread-4
iteration: 4 Thread-2
iteration: 5 Thread-3
error.
All the dependencies resolved.
Waiting for the remaining threads to complete their work.
Exception in thread "Thread-1" java.lang.ArithmeticException: / by zero
at ThreadProjectStructure.MainThread$2.run(MainThread.java:72)
iteration: 5 Thread-4
iteration: 5 Thread-2
iteration: 6 Thread-3
iteration: 6 Thread-4
iteration: 6 Thread-2
iteration: 7 Thread-3
iteration: 7 Thread-2
iteration: 7 Thread-4
iteration: 8 Thread-3
iteration: 8 Thread-2
iteration: 8 Thread-4
iteration: 9 Thread-3
iteration: 9 Thread-4
iteration: 9 Thread-2
All the threads have finished doing their work. Exiting now...
答案 0 :(得分：1)
你有没有想过使用线程池？如果您可以修改使用线程池的要求，如果出现异常，您可以强制关闭池，因此所有线程都将被停止。
答案 1 :(得分：1)
嗯，使用当前代码，您需要正确理解您的观点。请将锁定变量定义为自我解释，否则会让您感到困惑。假设您的要求如下：仅在线程2执行成功时继续执行其他线程。
以下是更新的代码：
import java.util.concurrent.CountDownLatch;
public class MainThread extends Thread{
static boolean flag=false;
final static CountDownLatch waitForThread2ToFinish= new CountDownLatch(1);
final static CountDownLatch waitForStartSignalFromThread1= new CountDownLatch(1);
final static CountDownLatch latchForAllOtherThreads= new CountDownLatch(3);
static MainThread t1;
static MainThread t2;
static MainThread t3;
static MainThread t4;
static MainThread t5;
public static void main(String args[]){
t1 = new MainThread(){
public void run(){
try {
System.out.println("Waiting for Thread 2 to finish");
waitForStartSignalFromThread1.countDown();
waitForThread2ToFinish.await();
if(flag==true){
System.out.println("Successful.");
t3.start();
t4.start();
t5.start();
System.out.println("All the dependencies resolved.");
System.out.println("Waiting for the remaining threads to complete their work.");
try {
latchForAllOtherThreads.await();
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("All the threads have finished doing their work. Exiting now...");
}
else{
System.out.println("Error.");
}
} catch (InterruptedException e) {
e.printStackTrace();
}
}
};
Thread t2 = new MainThread(){
public void run(){
System.out.println("Before Starting for loop");
try {
System.out.println("waiting for thread 1 to countdown latch2");
waitForStartSignalFromThread1.await();
System.out.println("Starting for loop");
for(int i=0;i<5;i++){
System.out.println("iteration: "+i);
try {
Thread.sleep(5);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
int x=1/0;
System.out.println("countdown by thread2 for latch 1 done.");
flag=true;
} catch (Exception e) {
e.printStackTrace();
}
finally{
waitForThread2ToFinish.countDown();
}
}
};
t3 = new MainThread(){
public void run(){
System.out.println("Running Thread 3");
for(int i=0;i<10;i++){
System.out.println("iteration: "+i+ " "+t3.getName());
try {
Thread.sleep(5);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
latchForAllOtherThreads.countDown();
}
};
t4 = new MainThread(){
public void run(){
System.out.println("Running Thread 4");
for(int i=0;i<10;i++){
System.out.println("iteration: "+i+ " "+t4.getName());
try {
Thread.sleep(5);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
latchForAllOtherThreads.countDown();
}
};
t5 = new MainThread(){
public void run(){
System.out.println("Running Thread 5");
for(int i=0;i<10;i++){
System.out.println("iteration: "+i+ " "+t5.getName());
try {
Thread.sleep(5);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
latchForAllOtherThreads.countDown();
}
};
t1.start();
t2.start();
}
}
答案 2 :(得分：0)
Java没有提供任何直接的方法来停止正在运行的线程的执行，但它提供了中断线程的方法。仍然不能保证停止执行线程，它只是将中断标志设置为该线程的true，它依赖于线程来检查标志并抛出中断的异常。这是停止执行线程的唯一优雅方式。 你可以通过调用handle.interrupt（）
来中断其他线程