线程---生产消费问题

class Ck{    private char[] rl=new char[8];    private int wp=0;    public synchronized void shengchan(char aa){        while(wp==rl.length){            try{                this.wait();            }catch(Exception e){            }        }            this.notify();//是当前线程处于就绪状态的前提下，叫醒另一个线程            rl[wp]=aa; ++wp;            System.out.println("生产线程正在生产第"+wp+"个产品，该产品是:"+aa);    }    public synchronized void xiaofei(){        char aa;        while(wp==0){            try{                this.wait();            }catch(Exception e){            }        }            this.notify();            aa=rl[wp-1];            System.out.println("消费线程正在消费第"+wp+"个产品，该产品是:"+aa);            --wp;    }}class Sc implements Runnable{    private Ck xc=null;    public Sc(Ck xc){        this.xc=xc;    }    public void run(){        char aa;        for(int i=0;i<26;i++){            aa=(char)('A'+i);            xc.shengchan(aa);        }    }}class Xf implements Runnable{    private Ck xc=null;    public Xf(Ck xc){        this.xc=xc;    }    public void run(){        for(int i=0;i<26;i++){            xc.xiaofei();        }    }}public class L6_9 {    public static void main(String[] args){        Ck ck=new Ck();        Sc sc=new Sc(ck);        Xf xf=new Xf(ck);        Thread xc1=new Thread(sc);        xc1.start();        Thread xc2=new Thread(xf);        xc2.start();    }}