yield
礼让线程，让当前正在执行的线程暂停而不是阻塞线程
将线程从运行状态转入就绪状态
让cpu调度器重新调度

public class n {public static void main(String[]args){ test t =new test(); new Thread(t,"a").start(); new Thread(t,"b").start();}}class test implements Runnable{public void run(){ System.out.println(Thread.currentThread().getName()+"-->start"); Thread.yield();//礼让 System.out.println(Thread.currentThread().getName()+"-->end");}}

例2：

public class n {public static void main(String[]args){ new Thread(()-> { for(int i=0;i<5;i++) { System.out.println("a"+i); } }).start(); for(int i=0;i<5;i++) { if(i%2==0) { Thread.yield(); } System.out.println("b"+i); }}}