JUC并发编程1

什么是juc

在java的java.util.concurrent包下的工具。

锁

传统的synchronize

public class SealTicket {int total = 50;public synchronized void seal() {if (total > 0) {System.out.println(Thread.currentThread().getName()+ "卖出第"+ (total--)+ "张，剩余：" + total);}}
}

JUC 的锁

public class SealTicket {int total = 50;Lock lock = new ReentrantLock();public void seal() {lock.lock();if (total > 0) {System.out.println(Thread.currentThread().getName()+ "卖出第"+ (total--)+ "张，剩余：" + total);}lock.unlock();}
}

Synchronize 和 Lock的区别

生产者和消费者问题

版本 synchronize

public class Data {int i = 0;public synchronized void add() throws InterruptedException {if (i != 0) {this.wait();}i++;System.out.println(Thread.currentThread().getName() + "=="+ i);this.notifyAll();}public synchronized void remove() throws InterruptedException {if (i == 0) {this.wait();}i--;System.out.println(Thread.currentThread().getName() + "=="+ i);this.notifyAll();}
}public class Producer {public static void main(String[] args) {Data data = new Data();new Thread(() -> {for (int i = 0; i < 60; i++) {try {data.add();} catch (InterruptedException e) {throw new RuntimeException(e);}}}, "a").start();new Thread(() -> {for (int i = 0; i < 60; i++) {try {data.remove();} catch (InterruptedException e) {throw new RuntimeException(e);}}}, "b").start();//        new Thread(() -> {
//            for (int i = 0; i < 60; i++) {
//                sealTicket.seal();
//            }
//        }, "c").start();}
}

版本 Lock

8锁问题

锁是什么，锁锁的是谁？