JAVA两个线程怎么同步_java-两个线程同时执行同步块
以下是Thread输入同步块，等待5秒然后退出的代码。 我同时启动了两个Thread实例。
预期其中一个线程将拥有对同步对象的锁定，而另一个将等待。 5秒后，当锁所有者退出时，将执行等待线程。
但是，实际上，两个线程同时执行同步块，并且同时退出。
预期产量：
Thread-X received the lock.
Thread-X exiting...
Thread-Y received the lock.
Thread-Y exiting...
实际输出：
Thread-X received the lock.
Thread-Y received the lock.
Thread-X exiting...
Thread-Y exiting...
我在这里想念什么吗？
import java.text.SimpleDateFormat;
import java.util.Date;
public class Test2 {
public static void main(String[] args) {
MyRunnable m = new MyRunnable();
Thread t = new Thread(m);
Thread t1 = new Thread(m);
t.start();
t1.start();
}
}
class MyRunnable implements Runnable {
@Override
public void run() {
synchronized (this) {
try {
SimpleDateFormat formatter = new SimpleDateFormat("dd/MM/yyyy HH:mm:ss");
Date date = new Date(System.currentTimeMillis());
System.out.println(Thread.currentThread().getName() + " " + formatter.format(date) + " received the lock.");
wait(5000);
date = new Date(System.currentTimeMillis());
System.out.println(Thread.currentThread().getName() + " " + formatter.format(date) + " exiting...");
} catch(InterruptedException ie) {}
}
}
}
以下是Thread输入同步块，等待5秒然后退出的代码。 我同时启动了两个Thread实例。 预期其中一个线程将拥有对同步对象的锁定，而另一个将等待。 5秒后，当锁所有者退出时，将执行等待线程。 但是，实际上，两个线程同时执行同步块，并且同时退出。 预期产量： Thread-X received the lock. Thread-X exiting... Thread-Y received the lock. Thread-Y exiting... 实际输出： Thread-X received the lock. Thread-Y received the lock. Thread-X exiting... Thread-Y exiting... 我在这里想念什么吗？ import java.text.SimpleDateFormat; import java.util.Date; public class Test2 { public static void main(String[] args) { MyRunnable m = new MyRunnable(); Thread t = new Thread(m); Thread t1 = new Thread(m); t.start(); t1.start(); } } class MyRunnable implements Runnable { @Override public void run() { synchronized (this) { try { SimpleDateFormat formatter = new SimpleDateFormat("dd/MM/yyyy HH:mm:ss"); Date date = new Date(System.currentTimeMillis()); System.out.println(Thread.currentThread().getName() + " " + formatter.format(date) + " received the lock."); wait(5000); date = new Date(System.currentTimeMillis()); System.out.println(Thread.currentThread().getName() + " " + formatter.format(date) + " exiting..."); } catch(InterruptedException ie) {} } } }