生成唯一性订单约束的四种方式锁（对象锁，类锁、分布式redis锁，分布式Zookeeper锁）

1.对象锁

package com.peopleyun.lock;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

/**
* Created by Administrator on 2018/1/3.
*/
public class ObjectLock {
public static int num = 0;
static ExecutorService executorService = Executors.newFixedThreadPool(2);

public static void main(String[] args) {

final OrderLock orderLock = new OrderLock();
executorService.execute(new Runnable() {
@Override
public void run() {

for (int i = 0; i < 100000 ; i ++ ){
System.out.println(Thread.currentThread().getName() + " " + orderLock.setInCrease());
}
}
});

executorService.execute(new Runnable() {
@Override
public void run() {

for (int i = 0; i < 100000 ; i ++ ){
System.out.println(Thread.currentThread().getName() + " " + orderLock.setInCrease());
}
}
});

try {
executorService.shutdown();
executorService.awaitTermination(100, TimeUnit.MILLISECONDS);
} catch (InterruptedException e) {
e.printStackTrace();
}

System.out.println(num);
}

static class OrderLock{
public synchronized String setInCrease(){
num ++;
return getStringDateShort() + num; //返回订单ID
}
}

public static String getStringDateShort() {
Date currentTime = new Date();
SimpleDateFormat formatter = new SimpleDateFormat("yyyyMMddHHmmss");
String dateString = formatter.format(currentTime);
return dateString;
}
}


2.类锁生成唯一性ID
package com.peopleyun.lock;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

/**
* Created by Administrator on 2018/1/3.
*/
public class ObjectLock {
public static int num = 0;
static ExecutorService executorService = Executors.newFixedThreadPool(2);

public static void main(String[] args) {

executorService.execute(new Runnable() {
@Override
public void run() {
OrderLock orderLock = new OrderLock();
for (int i = 0; i < 100000 ; i ++ ){
System.out.println(Thread.currentThread().getName() + " " + orderLock.setInCrease());
}
}
});

executorService.execute(new Runnable() {
@Override
public void run() {
OrderLock orderLock = new OrderLock();
for (int i = 0; i < 100000 ; i ++ ){
System.out.println(Thread.currentThread().getName() + " " + orderLock.setInCrease());
}
}
});

try {
executorService.shutdown();
executorService.awaitTermination(100, TimeUnit.MILLISECONDS);
} catch (InterruptedException e) {
e.printStackTrace();
}

System.out.println(num);
}

static class OrderLock{
public static synchronized String setInCrease(){
num ++;
return getStringDateShort() + num; //返回订单ID
}
}

public static String getStringDateShort() {
Date currentTime = new Date();
SimpleDateFormat formatter = new SimpleDateFormat("yyyyMMddHHmmss");
String dateString = formatter.format(currentTime);
return dateString;
}
}


3.  分布式Redis锁
package com.peopleyun.redisLock;

import redis.clients.jedis.Jedis;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Random;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

/**
* Created by Administrator on 2017/12/6.
*/
public class RedisLock {
public static int num = 0;
static ExecutorService executorService = Executors.newFixedThreadPool(2);
private static String ip = "10.1.15.53";
private static int port = 6379;
private static Jedis jedis;
private static String lock = "lock";
private static String lockvalue = "lockvalue";

public static void main(String[] args) {

executorService.execute(new Runnable() {
@Override
public void run() {
Jedis jedis = new Jedis(ip ,port,3000);
JedisLock jedisLock = new JedisLock(jedis);
for (int i = 0; i < 100000 ; i ++ ){
if(jedisLock.lock(10000,1)){
num++;
System.out.println(Thread.currentThread().getName() + " " + getStringDateShort() + " " + num);
}
jedisLock.unlock();
}
}
});

executorService.execute(new Runnable() {
@Override
public void run() {
Jedis jedis = new Jedis(ip ,port,3000);
JedisLock jedisLock = new JedisLock(jedis);
for (int i = 0; i < 100000 ; i ++ ){
if(jedisLock.lock(10000,1)){
num++;
System.out.println(Thread.currentThread().getName() + " " + getStringDateShort() + " "+ num);
}
jedisLock.unlock();
}
}
});

try {
executorService.shutdown();
executorService.awaitTermination(100, TimeUnit.MILLISECONDS);
} catch (InterruptedException e) {
e.printStackTrace();
}

}

static class JedisLock{

Jedis jedis;
JedisLock(Jedis jedis){
this.jedis = jedis;
jedis.del(lock);//直接删除
}
/* 加锁
* 使用方式为：
* lock();
* try{
* executeMethod();
* }finally{
* unlock();
* }
*
* @param expire 设置锁超时时间
* @return 成功 or 失败
*/
public boolean lock(long timeout,int expire){
long nanoTime = System.nanoTime();

try {
//在timeout的时间范围内不断轮询锁
while (true) {
//锁不存在的话，设置锁并设置锁过期时间，即加锁
if (jedis.setnx(lock, lockvalue) == 1L) {
jedis.expire(lock, expire);//设置锁过期时间是为了在没有释放
//锁的情况下锁过期后消失，不会造成永久阻塞
break;
}else {
System.out.println("出现锁等待");
//短暂休眠，避免可能的活锁
Thread.sleep(10);
}

}

} catch (Exception e) {
jedis = new Jedis(ip ,port,3000);
e.printStackTrace();
throw new RuntimeException("locking error",e);
}
return true;
}

public void unlock(){
try {
jedis.del(lock);//直接删除
} catch (Exception e) {
e.printStackTrace();
}
}
}

public static String getStringDateShort() {
Date currentTime = new Date();
SimpleDateFormat formatter = new SimpleDateFormat("yyyyMMddHHmmss");
String dateString = formatter.format(currentTime);
return dateString;
}
}


4.  Zookeeper分布式锁

package com.peopleyun.lock;

import org.I0Itec.zkclient.ZkClient;
import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.ZooDefs;
import org.apache.zookeeper.ZooKeeper;
import redis.clients.jedis.Jedis;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

/**
* Created by Administrator on 2017/12/6.
*/
public class ZkClientLock {

private static String lock = "/lock/lock33";

private static ZkClient zkClient;

private static CountDownLatch countDownLatch ;
public static int num = 0;
static ExecutorService executorService = Executors.newFixedThreadPool(2);

static {
zkClient = new ZkClient("10.1.15.53:2181");
ZkClientLock.unlock();
}

public static void lock(){
try {
zkClient.createEphemeral(lock);
}catch (Exception e){
try {
System.out.println("重新加锁。。。");
Thread.sleep(10);
lock();
} catch (InterruptedException e1) {
e1.printStackTrace();
}
}

}

public static void unlock(){
zkClient.delete(lock);
}

public static void main(String[] args) {
executorService.execute(new Runnable() {
@Override
public void run() {

for (int i = 0; i < 100000 ; i ++ ){
ZkClientLock.lock();
num++;
System.out.println(Thread.currentThread().getName() + " " + getStringDateShort() + " " + num);
ZkClientLock.unlock();
}
}
});

executorService.execute(new Runnable() {
@Override
public void run() {

for (int i = 0; i < 100000 ; i ++ ){
ZkClientLock.lock();
num++;
System.out.println(Thread.currentThread().getName() + " " + getStringDateShort() + " " + num);
ZkClientLock.unlock();
}
}
});

try {
executorService.shutdown();
executorService.awaitTermination(100, TimeUnit.MILLISECONDS);
} catch (InterruptedException e) {
e.printStackTrace();
}
}

public static String getStringDateShort() {
Date currentTime = new Date();
SimpleDateFormat formatter = new SimpleDateFormat("yyyyMMddHHmmss");
String dateString = formatter.format(currentTime);
return dateString;
}

}