java速度入五._多线程编程基础

首先是线程的创建和jion（）方法的使用。

class Sleeper extends Thread
{
private int sleeptime;
public Sleeper(String name,int sleepTime)
{
super(name);
sleeptime=sleepTime;
start();
}
public void run()
{
try
{
for(int i=0;i<5;i++)
{
System.out.println(getName()+"print"+i);
sleep(sleeptime);
}
}catch(InterruptedException e)
{
System.out.println(getName()+"interrupted");
}
System.out.println(getName()+" over");
}
}
class Joiner extends Thread
{
private Sleeper sleeper;
public Joiner(String name,Sleeper sleeper)
{
super(name);
this.sleeper=sleeper;
start();
}
public void run()
{
try
{
System.out.println(getName()+" Begin");
System.out.println(sleeper.getName()+"begin jion()....");
sleeper.join();
for(int i=5;i>0;i--)
{
System.out.println(getName()+"print:"+i);
}
}catch(Exception e)
{
e.printStackTrace();
}
System.out.println(getName()+"Over!");
}
}
public class SimpleJoin {

public static void main(String[] args)
{
Sleeper sleeper1=new Sleeper("Tread A sleeper1",1500),
sleeper2=new Sleeper("Tread A sleeper2",1000);
Joiner joiner=new Joiner("ThreadB",sleeper2);
sleeper1.interrupt();
//System.out.println("Hello");
}

}
创建三个Tread，第三个jion了第二个。
运行结果：
Tread A sleeper1print0
Tread A sleeper2print0
Tread A sleeper1interrupted
Tread A sleeper1 over
ThreadB Begin
Tread A sleeper2begin jion()....
Tread A sleeper2print1
Tread A sleeper2print2
Tread A sleeper2print3
Tread A sleeper2print4
Tread A sleeper2 over
ThreadBprint:5
ThreadBprint:4
ThreadBprint:3
ThreadBprint:2
ThreadBprint:1
ThreadBOver!
第二个是线程的共享与互斥问题 class Water { static Object pool=new Object(); static int total=6; //the volumn of the pool static int in=3; //the number of water which pool have static int out=0; //the water drain away } class ThreadA extends Thread//drain water class { void drain() { synchronized(Water.pool) { System.out.println("Empty or not?"+isEmpty()); if(isEmpty()) { try { Water.pool.wait(); }catch(InterruptedException e) { e.printStackTrace(); } } else { Water.out++; System.out.println("Drain out water:"+Water.out); } } } public void run(){ while(Water.in<Water.total){ if(isEmpty()) System.out.println("Empty"); System.out.println("Drain out water now!"); drain(); try{ sleep(1000); }catch(InterruptedException e){ e.printStackTrace(); } } } public boolean isEmpty() { return Water.in==Water.out?true:false; } } class ThreadB extends Thread{ void jswork(){ synchronized(Water.pool){ Water.in++; Water.pool.notify(); System.out.println("In :"+Water.in); } } public void run(){ while(Water.in<Water.total){ System.out.println("Empty"); jswork(); try{ sleep(3000); }catch(InterruptedException e){ e.printStackTrace(); } } } } public class pool { public static void main(String[] args) { ThreadA threadA=new ThreadA(); ThreadB threadB=new ThreadB(); threadB.start(); threadA.start(); //System.out.println("Hello!"); } } java中线程的同步有两种方法。 1.同步方法 synchronized void fun(){} 标记为synchronized的方法，在它执行完之前，其他标记为synchronized的方法都将被阻塞。 2.同步块 synchronized(someobject) {} 只有拥有运行代码权限的线程才能运行同步块内的代码。 java中的线程通信 主要用到wait()和notify()方法，和操作系统里的p，v操作类似，interrupt()用于终止进程。 例子说明：池塘的类，两个线程，排水和进水，当排水量和进水量相同时，排水量被挂起，直到进水进程注水完成后，才通知排水进程排水。