一:案例数据 (模拟多线程)
public class ThreadTest {
static Thread t1 = new Thread(new Runnable() {
@Override
public void run() {
System.err.println("t1 执行");
}
});
static Thread t2 = new Thread(new Runnable() {
@Override
public void run() {
System.err.println("t2 执行");
}
});
static Thread t3 = new Thread(new Runnable() {
@Override
public void run() {
System.err.println("t3 执行");
}
});
}
二:解决方案
1)设置线程的执行优先级(此方案不行)
public static void main(String[] args) throws InterruptedException{
//1:设置优先级(不能保证线程的执行顺序,只能加大执行的概率) 不行
t1.setPriority(Thread.MIN_PRIORITY);
t1.start();
t2.start();
t3.start();
}
2)join方法 (主线程阻塞,激活,阻塞,激活去依次执行t1,t2,t3) 可以 (比较基础,join方法是同步方法)
public static void main(String[] args) throws InterruptedException{
t1.start();
t1.join();
t2.start();
t2.join();
t3.start();
t3.join();
}
3)单例线程池 (阻塞队列,先进先出,只有一个核心主线程在执行) 可以,推荐
public static void main(String[] args) throws InterruptedException{
//3:单例线程池 (阻塞队列,先进先出)
ExecutorService executorService = Executors.newSingleThreadExecutor();
executorService.submit(t1);
executorService.submit(t2);
executorService.submit(t3);
executorService.shutdown();
}