多线程理解,线程

   最近在玩安卓,要提到多线程, 总感觉那东西有点不明白,总是有那些停止,暂停,销毁,启动什么的,总是执行那些程序,先后,快慢,说实话,不知道那是什么意思的,
   个人感觉多线程并不是什么情况下都适用的,一般用在定时功能,用得最好的只有播放器,听音乐的这些软件了, 有快进,有慢,有暂停,关闭这些都是多线程的,多线程的意义不在于共同执行一个任务或者是一段代码什么的, 他的意义在于,控制多个线程来完成一个任务,有选择的来完成,
   不知道理解错了没有,也就是自己的理解吧,确实不太明白

贴出多线程例子,看意思代码分析


package com.pu.gc;

public class TestThread{

    public static void main(String[] args) { 
         
        //创建饼的实例 
        Bing b = new Bing(); 
        //创建同步的吃饼和烙饼实例 
        GongNeng g = new GongNeng(b); 
        //创建线程两个消费者两个生产者 
        ChuShi c1 = new ChuShi(g); 
        ChuShi c2 = new ChuShi(g); 
        XiaoFei x1 = new XiaoFei(g); 
        XiaoFei x2 = new XiaoFei(g); 
         
        //启动线程 
        c1.start(); 
        c2.start(); 
        x1.start(); 
        x2.start(); 
    }
}

class ChuShi extends Thread{
   
    private GongNeng g; 
    public ChuShi(GongNeng g){
        this.g = g; 
    } 
     
    public void run(){ 
        for(;;){ 
            g.lao(); 
             
        } 
    } 
} 

class XiaoFei extends Thread{ 
    private GongNeng g; 
    public XiaoFei(GongNeng g){ 
        this.g = g; 
    } 
    public void run(){ 
        for(;;){ 
            g.chi(); 
        } 
    } 
} 

class GongNeng {
    private Bing b; 
    public GongNeng(Bing b){     
        this.b = b;  
    } 
    public synchronized void lao(){ 
        if(b.getBing()<10){ 
            try { 
                Thread.sleep(1500); 
            } catch (InterruptedException e) { 
                // TODO Auto-generated catch block 
                e.printStackTrace(); 
            } 
            System.out.println(Thread.currentThread()+ 
            ":厨师烙了一张饼，盘里还剩"+(b.getBing()+1)+"张饼"); 
            b.setBing(b.getBing()+1); 
        } 
    } 
     
    public synchronized void chi(){ 
        if(b.getBing()>0){ 
            try { 
                Thread.sleep(2000); 
            } catch (InterruptedException e) { 
                e.printStackTrace(); 
            } 
            System.out.println(Thread.currentThread()+ 
            ":消费者吃了一张饼，盘里还剩"+(b.getBing()-1)+"张饼"); 
            b.setBing(b.getBing()-1); 
        } 
    } 
} 

class Bing { 
    private int bing = 10; 
    public int getBing() { 
        return bing; 
    } 
    public void setBing(int bing) { 
        this.bing = bing; 
    } 
     
}