（Java多线程系列六）join()的用法和线程的优先级
join()的用法和线程的优先级
1、join()的用法
join()作用就是让其他线程处于等待状态
先看一个需求：创建一个线程，子线程执行完毕后，主线程才能执行
public class JoinThreadDemo {
public static void main(String[] args) {
Thread thread = new Thread(new Runnable() {
@Override
public void run() {
System.out.println("这里是子线程");
int count = 100;
while (count > 0) {
System.out.println(Thread.currentThread().getName() + "=====" + count);
count--;
}
}
});
thread.start();
try {
thread.join();
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("这里是主线程");
}
}
2、设置线程的优先级
在Java线程中，通过一个
int priority来控制优先级，范围为1-10，其中10最高，默认值为5。
注：设置了优先级，不代表每次都一定会被执行。只是CPU调度会优先分配
class PriorityThread extends Thread {
public PriorityThread(String name) {
this.setName(name);
}
@Override
public void run() {
System.out.println(getName() + "==========" + getId());
}
}
public class PriorityThreadDemo {
public static void main(String[] args) {
PriorityThread priorityThread1 = new PriorityThread("priority_10");
PriorityThread priorityThread2 = new PriorityThread("priority_default");
priorityThread1.setPriority(10);
priorityThread2.start();
priorityThread1.start();
}
}
