Java ReEntrantLock 之 Condition条件（Java代码实战-002）详解编程语言

import java.util.LinkedList; 
import java.util.concurrent.locks.Condition; 
import java.util.concurrent.locks.Lock; 
import java.util.concurrent.locks.ReentrantLock; 
 
/** 
 * ConditionTest 
 * 一个测试类，用Condition实现的生产者消费者问题 
 */ 
public class ConditionTest { 
    /* 定义一个容器（链表、队列） */ 
    private LinkedList<String> buffer; 
    /* 容器可以容纳元素的最大数量，通过构造函数来初始化 */ 
    private int maxSize; 
    private Lock lock; 
    private Condition fullCondition; 
    private Condition notFullCondition; 
 
    ConditionTest(int maxSize) { 
        this.maxSize = maxSize; 
        buffer = new LinkedList<String>(); 
        lock = new ReentrantLock(); 
        fullCondition = lock.newCondition(); 
        notFullCondition = lock.newCondition(); 
    } 
 
    /** 
     * 向容器中放入Element 
     */ 
    public void set(String string) throws InterruptedException { 
        // 获取锁 
        lock.lock(); 
        try { 
            while (maxSize == buffer.size()) { 
                // 满了，添加的线程进入等待状态 
                notFullCondition.await(); 
            } 
            buffer.add(string); 
 
            // 容器不为空时，则给等待的读取的线程发送信号以便唤醒这些线程进行读取 
            fullCondition.signal(); 
        } finally { 
            lock.unlock(); 
        } 
    } 
 
    /** 
     * 从容器中获取Element 
     */ 
    public String get() throws InterruptedException { 
        String string; 
        lock.lock(); 
        try { 
            while (buffer.size() == 0) { 
                // 如果容器为空，则读取的线程进入等待状态 
                fullCondition.await(); 
            } 
            string = buffer.poll(); 
 
            // 给写入的线程发送信号以便唤醒这些线程来往容器中写入 
            notFullCondition.signal(); 
        } finally { 
            lock.unlock(); 
        } 
        return string; 
    } 
}