目录Redisson简介Redisson实现分布式锁步骤引入依赖application.ymlRedisson

Redis

是世界上最流行注意没有说“最好”的编程语言之一。

虽然两者看起来很自然地在一起“工作”但是要知道Redis

其实并没有对

dependencygroupIdorg.redisson/groupIdartifactIdredisson/artifactIdversion3.6.5/version/dependencydependencygroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter-data-redis/artifactId/dependencyapplication.yml

server:port:

com.service.redis.servicespringbootredisdemo;import

import

org.springframework.boot.SpringApplication;

import

org.springframework.boot.autoconfigure.SpringBootApplication;

import

org.springframework.context.annotation.Bean;SpringBootApplication

public

ServiceSpringbootRedisDemoApplication

{public

{SpringApplication.run(ServiceSpringbootRedisDemoApplication.class,

args);}Beanpublic

Config();config.useSingleServer().setAddress(redis://127.0.0.1:6379).setDatabase(0);

config.useCustomServers().;return

(Redisson)

org.redisson.api.RedissonClient;

import

org.springframework.beans.factory.annotation.Value;

import

org.springframework.context.annotation.Bean;

import

org.springframework.context.annotation.Configuration;import

java.io.IOException;Configuration

public

{Value(${spring.redis.host})private

String

host;Value(${spring.redis.port})private

String

port;//Value(${spring.redis.password})//private

String

IOException*/Bean(destroyMethod

shutdown)public

Config();//config.useSingleServer().setAddress(redis://

host

port).setPassword(password);config.useSingleServer().setAddress(redis://

host

com.service.redis.servicespringbootredisdemo.test;import

import

org.springframework.beans.factory.annotation.Autowired;

import

org.springframework.data.redis.core.StringRedisTemplate;

import

org.springframework.web.bind.annotation.RequestMapping;

import

org.springframework.web.bind.annotation.RestController;import

java.util.UUID;

java.util.concurrent.TimeUnit;RestController

public

LoggerFactory.getLogger(TestController.class);Autowiredprivate

Redisson

stringRedisTemplate;RequestMapping(deductStock1)public

String

{//加锁,实现锁续命功能redissonLock.lock();//尝试加锁,最大等待时间300毫秒上锁30毫秒自动解锁//if

(redissonLock.tryLock(300,30,TimeUnit.MILLISECONDS)){//你自己的业务啊随便写int

stock

Integer.parseInt(stringRedisTemplate.opsForValue().get(stock));if

(stock

1;stringRedisTemplate.opsForValue().set(stock,

realStock

{System.out.println(扣减失败);}//}}

catch

{//解锁redissonLock.unlock();}return

end;}

tryLock一般用于特定满足需求的场合但不建议作为一般需求的分布式锁一般分布式锁建议用void

lock(long

unit)。

因为从性能上考虑在高并发情况下后者效率是前者的好几倍。

tryLock(long

在源码中出现leaseTime时间判断的有2个分支实际上就是加锁时是否设置过期时间未设置过期时间-1时则会有watchDog的锁续约注册了加锁事件的续约任务。

package

com.service.redis.servicespringbootredisdemo.test;import

import

org.springframework.beans.factory.annotation.Autowired;

import

org.springframework.data.redis.core.StringRedisTemplate;

import

org.springframework.web.bind.annotation.RequestMapping;

import

org.springframework.web.bind.annotation.RestController;import

java.util.UUID;

java.util.concurrent.TimeUnit;RestController

public

LoggerFactory.getLogger(TestController.class);Autowiredprivate

Redisson

stringRedisTemplate;RequestMapping(deductStock)public

String

UUID.randomUUID().toString();try

{//下面这行代码相当于jedis.setnx(key,value);

Boolean

stringRedisTemplate.opsForValue().setIfAbsent(lockKey,

stringRedisTemplate.expire(lockKey,10,

不管是30还是多少有的线程执行多有的少.缺少一个自动续期。

Boolean

result

stringRedisTemplate.opsForValue().setIfAbsent(lockKey,

uuid,

{System.out.println(取锁失败请稍后重试。

);//这里也可以处理自己的业务。

返回错误码什么的、return

error;}int

Integer.parseInt(stringRedisTemplate.opsForValue().get(stock));if

(stock

1;stringRedisTemplate.opsForValue().set(stock,

realStock

(uuid.equals(stringRedisTemplate.opsForValue().get(lockKey)))//保证每个线程只删自己的。

stringRedisTemplate.delete(lockKey);}return

end;}}