线程类算法题记录

一.线程类

1.使用多线程交替打印0-99。

使用Callable

public class MyCallable{
	public static void main(String[] args){
		MyCallable2 myCallable1=new MyCallable2();
		FutureTask fk1=new FutureTask(myCallable1);
		Thread t3=new Thread(fk1);
		MyCallable2 myCallable2=new MyCallable2();
		FutureTask fk2=new FutureTask(myCallable2);
		Thread t4=new Thread(fk2);
		t3.start();
		t4.start();
		try{
			String str1=(String)fk1.get();
			String str2=(String)fk2.get();
			System.out.println(str1);
			System.out.println(str2);
		}catch(ExeutionException e){
			e.printStackTrace();
		}catch(InterruptedException e){
			e.printStackTrace();
		}
	}
}

class MyCallable2 implements Callable{
	private static int i=0;
	private static Object lock=new Object();
	@Override
	public Object call() throws Exception{
		while(true){
			synchronized(lock){
				lock.notify();
				if(i>100){
					break;
				}
				System.out.println(Thread.currentThread()+" i="+i++);
				try{
					lock.wait();
				}catch(InterruptedException e){
					e.printStackTrace();
				}
			}
		}
		System.out.println(Thread.currentThread()+" finished");
		return "hello world "+Thread.currentThread();
	}
}

使用Runnable

public class MyThread{
	public static void main(String[] args){
		MyRunnable myRunnable=new MyRunnable();
		Thread thread1=new Thread(myRunnable);
		Thread thread2=new Thread(myRunnable);
		thread1.start();
		thread2.start();
	}
}

class MyRunnable implements Runnable{
	private static int i=0;
	@Override
	public void run(this){
		notify();
		if(i>=100){
			break;
		}
		try{
			System.out.println(Thread.currentThread()+" i="+i++);
			wait();
		}catch(InterruptedException e){
			e.printStackTrace();
		}
	}
	System.out.println(Thread.currentThread().getName()+"执行完毕");
}

使用Thread

//匿名内部类实现
public class MyThread2{
	static int i=0;
	static Object lock=new Object();
	public static void main(String[] args){
		Thread t1=new Thread(new Runnable(){
			@Override
			public void run(){
				System.out.println(Thread.currentThread().getName());
				while(true){
					synchronized(lock){
						lock.notify();
						if(i>=100){
							break;
						}
						try{
							System.out.println(Thread.currentThread()+" i="+i++);
							lock.wait();
						}catch(Exception e){
							e.printStackTrace();
						}
					}
				}
			}
		});
		Thread t2=new Thread(new Runnable(){
			@Override
			public void run(){
				System.out.println(Thread.currentThread().getName());
				while(true){
					synchronized(lock){
						lock.notify();
						if(i>=100){
							break;
						}
						try{
							System.out.println(Thread.currentThread()+" i="+i++);
							lock.wait();
						}catch(Exception e){
							e.printStackTrace();
						}
					}
				}
			}
		});
		t1.start();
		t2.start();
	}
}

//重写Thread的run方法
public class PrintNumThread extends Thread{
	static int num=0;
	static Object object=new Object();

	@Override
	public void run(){
		while(true){
			synchronized(object){
				//唤醒等待的线程 必须在同步代码块中
				object.notify();
				if(num<100){
					num++;
					System.out.println(Thread.currentThread().getName()+":"+num);
				}else{
					break;
				}
				try{
					/*
					 wait() 必须在同步代码块中使用，
					 		必须是使用同步锁调用wait()
					 		wait()调用后，锁会释放
					 		必须要通过其他线程来唤醒
					*/
					object.wait();
				}catch(InterruptedException e){
					e.printStackTrace();
				}
			}
		}
	}
	public static void main(String[] args){
		PrintNumThread p1=new PrintNumThread();
		PrintNumThread p2=new PrintNumThread();
		p1.start();
		p2.start();
	}
}