worker.java

java2应用开发指南第一版

【代码9-5-1】
//Worker.java
class Worker extends Thread 
{
    private int count;
    private boolean done = false;
    private boolean suspended = false;
	//同步方法
synchronized void safeStop()
{
        System.out.println("stopped");
        done = true;
}
//同步方法
synchronized void safeSuspend()
{
        System.out.println("suspended");
        suspended = true;
    }
//同步方法
synchronized void safeResume()
{
        System.out.println("resumed");
        suspended = false;
        notify();
}
//判断标志变量
synchronized boolean ok()
{
        return (!done);
}
//线程实际执行的方法
synchronized void doWork()
{
        if (!suspended)
{
            // do something useful
            ++count;
        }
else
{
while (suspended)
{
                try
{
                    wait();
                }
catch (InterruptedException e)
{
                }
            }
        }
}
//线程的run方法
public void run()
{
        while (ok())
{
            doWork();
        }
    }
}