JAVA 4个线程依次输出1 2 3 4

迈不过友情╰ 2022-08-14 03:50 127阅读 0赞

public class Test {
    
    	int task = 1;
    
    	public static void main(String[] args) {
    		Test t = new Test();
    		Thread a = new ThreadA(t);
    		Thread b = new ThreadB(t);
    		Thread c = new ThreadC(t);
    		Thread d = new ThreadD(t);
    		b.start();
    		c.start();
    		d.start();
    		a.start();
    	}
    
    }
    
    class ThreadA extends Thread {
    
    	private Test t;
    
    	public ThreadA(Test t) {
    		this.t = t;
    	}
    
    	@Override
    	public void run() {
    
    		while (true) {
    			System.out.println("thread A");
    			synchronized (t) {
    				if (t.task == 1) {
    					try {
    						t.wait();
    					} catch (InterruptedException e) {
    						e.printStackTrace();
    					}
    					System.out.println(t.task);
    					t.task = 2;
    					break;
    				}
    				t.notify();
    			}
    		}
    	}
    }
    
    class ThreadB extends Thread {
    
    	private Test t;
    
    	public ThreadB(Test t) {
    		this.t = t;
    	}
    
    	@Override
    	public void run() {
    		while (true) {
    			synchronized (t) {
    				if (t.task == 2) {
    					try {
    						t.wait();
    					} catch (InterruptedException e) {
    						e.printStackTrace();
    					}
    					System.out.println(t.task);
    					t.task = 3;
    					break;
    				}
    				t.notify();
    			}
    		}
    	}
    }
    
    class ThreadC extends Thread {
    
    	private Test t;
    
    	public ThreadC(Test t) {
    		this.t = t;
    	}
    
    	@Override
    	public void run() {
    		while (true) {
    			synchronized (t) {
    
    				if (t.task == 3) {
    					try {
    						t.wait();
    					} catch (InterruptedException e) {
    						e.printStackTrace();
    					}
    					System.out.println(t.task);
    					t.task = 4;
    					break;
    				}
    				t.notify();
    			}
    		}
    	}
    }
    
    class ThreadD extends Thread {
    
    	private Test t;
    
    	public ThreadD(Test t) {
    		this.t = t;
    	}
    
    	@Override
    	public void run() {
    		while (true) {
    			synchronized (t) {
    
    				if (t.task == 4) {
    					System.out.println(t.task);
    					break;
    				}
    				t.notify();
    			}
    		}
    	}
    }