Condition 的使用

场景：一个线程因为某个condition不满足被挂起，直到该Condition被满足了，作用类似Object的wait/notify。

使用Condition完成似消费者生产者模型

package com.hts;


import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

class ConditionTest {
    final Lock lock = new ReentrantLock();
    final Condition notFull     = lock.newCondition();
    final Condition notEmpty = lock.newCondition();

    int maxSize;
    List<Object> dataList=Collections.synchronizedList(new ArrayList<>());


    public ConditionTest(int maxSize){
        this.maxSize = maxSize;
    }
    public void put(String product) throws InterruptedException {
        lock.lock();
        try {
            while (maxSize == dataList.size())
                notFull.await();
            dataList.add(new Object());
            System.out.println(product+"生产一个产品，当前大小："+dataList.size());
            notEmpty.signal();
        } finally {
            lock.unlock();
        }
    }

    public void take(String consumer) throws InterruptedException {
        lock.lock();
        try {
            while (dataList.size() == 0)
                notEmpty.await();
            dataList.remove(0);
            System.out.println(consumer+"消费一个产品当前大小："+dataList.size());
            notFull.signal();
        } finally {
            lock.unlock();
        }
    }

    public static void main(String[] args) {
        ConditionTest conditionTest = new ConditionTest(100);
        for(int i = 0;i<1000;i++){
            int id = i+1;
            new Thread(new Runnable() {
                @Override
                public void run() {
                    try {
                        conditionTest.put("生产者"+id);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }).start();
            new Thread(new Runnable() {
                @Override
                public void run() {
                    try {
                        conditionTest.take("消费者"+id);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }).start();
        }
    }
}