优先级priority，调用的概率，建议在start之前设定
.setPriprity(num);可以是数组或下列常量;
取值1到10,
NORM_PRIORITY 5所有线程默认为5
MIN_PRIORITY 1
MAX_PRIORITY 10
.getPriority()获得当前线程优先级

public class n {public static void main(String[]args) throws InterruptedException{ System.out.println(Thread.currentThread().getPriority()); test t=new test(); Thread t1=new Thread(t); Thread t2=new Thread(t); Thread t3=new Thread(t); Thread t4=new Thread(t); Thread t5=new Thread(t); Thread t6=new Thread(t); t1.setPriority(Thread.MAX_PRIORITY); t2.setPriority(Thread.MAX_PRIORITY); t3.setPriority(Thread.MAX_PRIORITY); t4.setPriority(Thread.MIN_PRIORITY); t5.setPriority(Thread.MIN_PRIORITY); t6.setPriority(Thread.MIN_PRIORITY); //设置优先级在启动前 t1.start(); t2.start(); t3.start(); t4.start(); t5.start(); t6.start();}}class test implements Runnable{public void run(){ System.out.println(Thread.currentThread().getName()+"-->"+Thread.currentThread().getPriority()); Thread.yield();}}