分布式锁解决方案_基于Redisson实现的分布式锁实现

Redisson介绍： https://github.com/redisson/redisson/wiki

Redisson - 是一个高级的分布式协调Redis客服端，能帮助用户在分布式环境中轻松实现一些Java的对象，Redisson、Jedis、Lettuce是三个不同的操作 Redis 的客户端，Jedis、Lettuce 的 API 更侧重对Reids 数据库的CRUD（增删改查），而Redisson API 侧重于分布式开发。

在pom.xml中加入相关依赖：


<dependency>
    <groupId>org.redisson</groupId>
    <artifactId>redisson-spring-boot-starter</artifactId>
    <version>3.17.2</version>
</dependency>

编写Redis分布式锁工具类

创建包utils并创建工具类RedissonLockUtils

package com.ss.demo.utils;
import lombok.extern.slf4j.Slf4j;
import org.redisson.Redisson;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import java.util.concurrent.TimeUnit;
/**
* 分布式所
*/
@Slf4j
@Component
public class RedissonLockUtils {
    @Autowired
    private RedissonClient redissonClient;
    /**
     * 上锁
     * @param lockName
     * @return
     */
    public Boolean lock(String lockName) {
        //判断客户端是否存在
        if(redissonClient == null) {
            log.info("RedissonLock is null");
            return false;
        }
        try {
            //加锁
            RLock lock = redissonClient.getLock(lockName);
            //过期时间为10秒钟
            //这里无需手动解锁,到10秒钟会自动解锁
            lock.lock(10, TimeUnit.SECONDS);
            return true;
        }catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }
    /**
     * 解锁
     * @param lockName
     * @return
     */
    public Boolean unLock(String lockName) {
        //判断客户端是否存在
        if(redissonClient == null) {
            log.info("RedissonLock is null");
            return false;
        }
        try {
            //获得那把锁
            RLock lock = redissonClient.getLock(lockName);
            lock.unlock();    //解锁
            return true;
        }catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }
}

然后修改service的接口ITOrderService

package com.ss.demo.service;
import com.baomidou.mybatisplus.extension.service.IService;
import com.ss.demo.domain.TOrder;

/**
* <p>
* 服务类
* </p>
*/
public interface ITOrderService extends IService<TOrder> {
    /**
     * 创建订单方法
     * @param productId
     * @param count
     * @return
     */
    String createOrder(Integer productId, Integer count);
    /**
     * 使用悲观锁进行实现
     * @param productId
     * @param count
     * @return
     */
    String createOrderPessimisticlock(Integer productId, Integer count);
    /**
     * 乐观锁
     * @param productId
     * @param count
     * @return
     */
    String createOrderOptmisticlock(Integer productId, Integer count);
    /**
     * Redis操作
     * @param productId
     * @param count
     * @return
     */
    String createOrderRedis(Integer productId, Integer count);
    /**
     * Redisson操作
     * @param productId
     * @param count
     * @return
     */
    String createOrderRedisson(Integer productId, Integer count);
}

修改service的实现类TOrderServiceImpl

//引入redisson工具类进行上锁和解锁的操作
@Autowired
private RedissionUtils redissonLockUtils;/*** redisson* @param productId* @param count* @return*/
@Override
public String createOrderRedisson(Integer productId, Integer count) {//加锁操作String  key = "lock:";Boolean lock = redissonLockUtils.lock(key + productId);  //上锁//是否获得了锁if(!lock) {   //如果未获得锁return "未获得锁";}try {//根据商品id获取商品信息Product product = productMapper.selectById(productId);if(product == null) {throw new RuntimeException("购买商品不存在");}log.info(Thread.currentThread().getName() +"库存数量" + product.getCount());//校验库存if(count > product.getCount()) {throw new RuntimeException("库存不足");}//更新库存product.setCount(product.getCount() - count);//更新操作productMapper.updateById(product);//创建订单操作TOrder order = new TOrder();order.setOrderStatus(1);order.setReceiverName("张三");order.setReceiverMobile("12345678765");//设置订单价格【商品单价*商品数量】order.setOrderAmount(product.getPrice().multiply(new BigDecimal(count)));orderMapper.insert(order);  //插入订单操作//创建订单商品表的操作OrderItem orderItem = new OrderItem();orderItem.setOrderId(order.getId());     //订单IdorderItem.setProduceId(product.getId());  //商品IdorderItem.setPurchasePrice(product.getPrice()); //购买价格orderItem.setPurchaseNum(count);   //购买数量orderItemMapper.insert(orderItem);return order.getId();} catch (Exception e) {e.printStackTrace();} finally {redissonLockUtils.unlock(key + productId);}return "失败";
}

修改controller：TOrderController

package com.ss.demo.controller;
import com.ss.demo.service.ITOrderService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.AutoConfigureOrder;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
/**
* <p>
* 前端控制器
* </p>
*/
@RestController
@RequestMapping("/order")
public class TOrderController {
    @Autowired
    private ITOrderService orderService;

    @PostMapping("/create")
    public String createOrder(Integer productId, Integer count) {
        //return orderService.createOrder(productId, count);
        //return orderService.createOrderRedis(productId,count);
        return orderService.createOrderRedisson(productId, count);
    }
}