needforsynchronizationdemo.java

java 多线程同步

//NeedForSynchronizedDemo.java
import java.io.*;
class NeedForSynchronizationDemo
{
	public static void main(String[] args)
	{
		FinTrans ft = new FinTrans();
		TransThread tt1=new TransThread(ft,"Deposit Thread");
		TransThread tt2=new TransThread(ft,"Withdrawl Thread");
		tt1.start();
		tt2.start();
	}
}
class FinTrans
{
	public static String transName;
	public static double amount;
}
class TransThread extends Thread
{
	private FinTrans ft;
	TransThread(FinTrans ft,String name)
	{
		super(name);
		this.ft=ft;
	}
	public void run()
	{
		for(int i=0;i<100;i++)
		{
			if(getName().equals("Deposit Thread"))
			//Start of deposit thread's critical code section
			{
				ft.transName="Deposit";
				try
				{
					Thread.sleep((int)(Math.random()*1000));
				}
				catch(InterruptedException e)
				{}
				ft.amount=2000.0;
				System.out.println(ft.transName+" "+ft.amount);
				//the end of deposit section
			}
			else
			{
				//the start of withdrawl"
				ft.transName="Withdrawl";
				try
				{
					Thread.sleep((int)(Math.random()*1000));
				}
				catch(InterruptedException e)
				{}
				ft.amount=250.0;
				System.out.println(ft.transName+" "+ft.amount);
				//the end of withdrawl section
			}
		}
	}
}