夜光序言：
情话躲在风里
喜欢的人藏在梦里
你还在我心里
正文：
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
public class LockExample {
private static final ReentrantLock queueLock = new ReentrantLock(); //夜光 可重入锁
private static final ReentrantReadWriteLock orderLock = new ReentrantReadWriteLock(); //夜光 可重入读写锁
/**
* 夜光
* 有家奶茶店，点单有时需要排队
* 假设想买奶茶的人如果看到需要排队，就决定不买
* 又假设奶茶店有老板和多名员工，记单方式比较原始，只有一个订单本
* 老板负责写新订单，员工不断地查看订单本得到信息来制作奶茶，在老板写新订单时员工不能看订单本
*
* 夜光 这就是一个读写分离的情况~~
*
* 多个员工可同时看订单本，在员工看时老板不能写新订单
* @param args
* @throws InterruptedException
*/
public static void main(String[] args) throws InterruptedException {
//buyMilkTea();
handleOrder(); //需手动关闭
}
public void tryToBuyMilkTea() throws InterruptedException {
boolean flag = true;
while(flag)
{
if (queueLock.tryLock()) {
//queueLock.lock();
long thinkingTime = (long) (Math.random() * 500);
Thread.sleep(thinkingTime);
System.out.println(Thread.currentThread().getName() + "： 来一杯夜光牌珍珠奶茶，不要珍珠");
flag = false;
queueLock.unlock(); // 夜光 我们把资源释放掉~~
} else {
//System.out.println(Thread.currentThread().getName() + "：" + queueLock.getQueueLength() + "人在排队");
System.out.println(Thread.currentThread().getName() + "： 再等等");
}
if(flag)
{
Thread.sleep(1000);
}
}
}
public void addOrder() throws InterruptedException {
orderLock.writeLock().lock();
long writingTime = (long) (Math.random() * 1000);
Thread.sleep(writingTime);
System.out.println("架构师新加一笔订单");
orderLock.writeLock().unlock();
}
public void viewOrder() throws InterruptedException {
orderLock.readLock().lock();
// 夜光，下面几行代码都可以共享readLock()，不像之前的
long readingTime = (long) (Math.random() * 500);
Thread.sleep(readingTime);
System.out.println(Thread.currentThread().getName() + ": 查看订单本");
orderLock.readLock().unlock();
}
public static void buyMilkTea() throws InterruptedException {
LockExample lockExample = new LockExample();
int STUDENTS_CNT = 10;
Thread[] students = new Thread[STUDENTS_CNT];
// 夜光 下面我们完成了student数组的初始化工作~~
for (int i = 0; i < STUDENTS_CNT; i++) {
students[i] = new Thread(new Runnable() {
@Override
public void run() {
try {
long walkingTime = (long) (Math.random() * 1000);
Thread.sleep(walkingTime);
lockExample.tryToBuyMilkTea();
} catch(InterruptedException e) {
System.out.println(e.getMessage());
}
}
}
);
students[i].start();
}
for (int i = 0; i < STUDENTS_CNT; i++)
students[i].join();
}
public static void handleOrder() throws InterruptedException {
LockExample lockExample = new LockExample();
Thread boss = new Thread(new Runnable() {
@Override
public void run() {
while (true) {
try {
lockExample.addOrder();
long waitingTime = (long) (Math.random() * 1000);
Thread.sleep(waitingTime);
} catch (InterruptedException e) {
System.out.println(e.getMessage());
}
}
}
});
boss.start();
int workerCnt = 3;
Thread[] workers = new Thread[workerCnt];
for (int i = 0; i < workerCnt; i++)
{
workers[i] = new Thread(new Runnable() {
@Override
public void run() {
while (true) {
try {
lockExample.viewOrder();
long workingTime = (long) (Math.random() * 5000);
Thread.sleep(workingTime);
} catch (InterruptedException e) {
System.out.println(e.getMessage());
}
}
}
});
workers[i].start();
}
}
}