(三)多個生產者多個消費者，給包子編號 ,用lock

package com.ProudceCustom;
import java.util.ArrayList;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
public class ProduceCustom2 {
public static void main(String[] args) {
produce2 p1 = new produce2();
produce2 p2 = new produce2();
p1.setName("生產者1");
p2.setName("生產者1");
custom2 c1 = new custom2();
custom2 c2 = new custom2();
c1.setName("消費者1");
c2.setName("消費者2");
p1.start();
p2.start();
c1.start();
c2.start();
}
}
class Baozi2{
//public  int id;//id和i在同一個類時能夠不用靜態或者直接不用id
public  static ArrayList<Baozi> list=new ArrayList<Baozi>();
public static int sum=6;
public static  int i;
public  static Lock lock=new ReentrantLock();
public  static Condition p=lock.newCondition();
public  static Condition c=lock.newCondition();
}
class produce2 extends Thread{
@Override
public void run() {
while(true){
Baozi2.lock.lock();
while(Baozi2.list.size()>=Baozi2.sum){
try {
Baozi2.p.await();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
Baozi bz=new Baozi();
Baozi2.i++;
bz.id=Baozi2.i;
            try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
        // 添加到數組中。
            Baozi2.list.add(bz);
            System.out.println(Thread.currentThread().getName()
+ "生產了一個包子:" + bz.id + "，現有" + Baozi2.list.size());
         // 喚醒對方(生產者)
            Baozi2.c.signal();
            Baozi2.lock.unlock();
}
}
}
class custom2 extends Thread{
@Override
public void run() {
while(true){
Baozi2.lock.lock();
while(Baozi2.list.size()==0){
try {
Baozi2.c.await();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
int index = (int) (Math.random() * Baozi2.list.size());
Baozi baozi2 = Baozi2.list.remove(index);
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println(Thread.currentThread().getName()
+ "消費了一個包子，id爲" + baozi2.id + "，現有"
+ Baozi2.list.size());
//喚醒對方
Baozi2.p.signal();
Baozi2.lock.unlock();
}
}
}