关于多线程的问题 - 黑马程序员技术交流社区

class ProduceConsume
{
public static void main(String[] args)
{
Res r=new Res();
new Thread(new Produce(r)).start();
new Thread(new Consume(r)).start();
new Thread(new Produce(r)).start();
new Thread(new Consume(r)).start();
new Thread(new Produce(r)).start();
new Thread(new Consume(r)).start();
new Thread(new Produce(r)).start();
new Thread(new Consume(r)).start();
new Thread(new Produce(r)).start();
new Thread(new Consume(r)).start();
new Thread(new Produce(r)).start();
new Thread(new Consume(r)).start();
//问题是.开启这么多线程就出问题了.打印结果.求解决因为什么??????????????
/*
Thread-0生产商品..244
Thread-7消费.........商品..244
Thread-6生产商品..245
Thread-1消费.........商品..245
Thread-5消费.........商品..245
Thread-4生产商品..246
Thread-5消费.........商品..246
Thread-1消费.........商品..246
Thread-6生产商品..247
Thread-7消费.........商品..247
Thread-0生产商品..248
Thread-8生产商品..249
Thread-9消费.........商品..249
Thread-3消费.........商品..249
*/
}
}
class Res
{
private String name;
private int count;//计数
private boolean flag;//用于判断if是否该执行
public synchronized void set(String name)//存入线程
{
if(flag)//如果是假等待
try
{
this.wait();
}
catch (Exception e)
{
}
this.name=name+".."+count++;//如果是真.赋值并计数打印
System.out.println(Thread.currentThread().getName()+"生产"+this.name);
flag=true;//然后变成真.并把全部线程唤醒
this.notifyAll();
}
public synchronized void out()//打印线程
{
if(!flag)//如果非假开始等待
try
{
this.wait();
}
catch (Exception e)
{
}
//否则就打印.并且改为假.并把全部线程唤醒
System.out.println(Thread.currentThread().getName()+"消费........."+this.name);
flag=false;
this.notifyAll();
}
}
class Produce implements Runnable//存入线程
{
private Res r;//建立对象引用
Produce(Res r)
{
this.r=r;//初始化对象
}
public void run()
{
while(true)//往里存商品.
{
r.set("商品");
}
}
}
class Consume implements Runnable//打印线程
{
private Res r;//建立对象引用
Consume(Res r)
{
this.r=r;
}
public void run()
{
while(true)//打印商品
r.out();
}
}

复制代码

class Resource
{
private String name;
private int count=1;
private boolean flag=false;
public synchronized void set(String name)
{
while(flag) //加上while判断标记
try{this.wait();}catch(Exception e){} //等待
this.name=name+"----"+count++;
System.out.println(Thread.currentThread().getName()+"...生产者..."+this.name);
flag=true;
this.notifyAll();//唤醒全部
}
public synchronized void out()
{
while(!flag)
try{this.wait();}catch(Exception e){}
System.out.println(Thread.currentThread().getName()+"......消费者......"+this.name);
flag=false;
this.notifyAll();
}
}
class Producer implements Runnable
{
private Resource res;
Producer(Resource res)
{
this.res=res;
}
public void run()
{
while(true)
{
res.set("==商品==");
}
}
}
class Consumer implements Runnable
{
private Resource res;
Consumer(Resource res)
{
this.res=res;
}
public void run()
{
while(true)
{
res.out();
}
}
}
class Demo2
{
public static void main(String[] args)
{
Resource r = new Resource();
Producer pro = new Producer(r);
Consumer con = new Consumer(r);
Thread t1 = new Thread(pro);
Thread t2 = new Thread(pro);
Thread t3 = new Thread(con);
Thread t4 = new Thread(con);
t1.start();
t2.start();
t3.start();
t4.start();
}
}

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