SpringBoot使用Redis实现分布式锁

<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>

/**
 * 获取锁
 * @param lockKey 锁
 * @param identity 身份标识（保证锁不会被其他人释放）
 * @param expireTime 锁的过期时间（单位：秒）
 * @return
 */
public boolean lock(String lockKey, String identity, long expireTime){
  boolean lockResult = redisTemplate.opsForValue().setIfAbsent(lockKey, identity, expireTime, TimeUnit.SECONDS);
  return opsForValue;
}

/**
 * 释放锁
 * @param lockKey 锁
 * @param identity 身份标识（保证锁不会被其他人释放）
 * @return
 */
public boolean releaseLock(String lockKey, String identity){
  String luaScript =
    "if " +
    "  redis.call('get', KEYS[1]) == ARGV[1] " +
    "then " +
    "  return redis.call('del', KEYS[1]) " +
    "else " +
    "  return 0 " +
    "end";
  DefaultRedisScript<Boolean> redisScript = new DefaultRedisScript<>();
  redisScript.setResultType(Boolean.class);
  redisScript.setScriptText(luaScript);
  List<String> keys = new ArrayList<>();
  keys.add(lockKey);
  boolean result = redisTemplate.execute(redisScript, keys, identity);
  return result;
}

package com.qixi.lock.demo.lockdemo.controller;

import com.qixi.lock.demo.lockdemo.util.RedisLock;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

/**
 * 测试分布式锁
 * @author ZhengNC
 * @date 2020/5/13 17:27
 */
@RestController
@RequestMapping("test")
public class TestRedisLockController {

  private final String lockKeyName = "testKey";

  @Autowired
  private RedisLock redisLock;

  /**
   * 测试加锁
   * @param id 加锁的资源id
   * @param identity 身份标识
   * @return
   */
  @GetMapping("lock")
  public String lock(@RequestParam("id") String id,
            @RequestParam("identity") String identity){
    String lockKey = lockKeyName+":"+id;
    boolean lockSuccess = redisLock.lock(lockKey, identity, 60);
    String result = "lock failed";
    if (lockSuccess){
      result = "lock success";
    }
    return result;
  }

  /**
   * 测试释放锁
   * @param id 释放锁的资源id
   * @param identity 身份标识
   * @return
   */
  @GetMapping("release")
  public String release(@RequestParam("id") String id,
            @RequestParam("identity") String identity){
    String lockKey = lockKeyName+":"+id;
    boolean releaseSuccess = redisLock.releaseLock(lockKey, identity);
    String result = "release failed";
    if (releaseSuccess){
      result = "release success";
    }
    return result;
  }
}

package com.qixi.lock.demo.lockdemo.util;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Component;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;

/**
 * 分布式锁Redis工具类
 * @author ZhengNC
 * @date 2020/5/13 17:27
 */
@Component
public class RedisLock {

  @Autowired
  private RedisTemplate<String, String> redisTemplate;

  /**
   * 获取锁
   * @param lockKey 锁
   * @param identity 身份标识（保证锁不会被其他人释放）
   * @param expireTime 锁的过期时间（单位：秒）
   * @return
   */
  public boolean lock(String lockKey, String identity, long expireTime){
    boolean lockResult = redisTemplate.opsForValue().setIfAbsent(lockKey, identity, expireTime, TimeUnit.SECONDS);
    return lockResult;
  }

  /**
   * 释放锁
   * @param lockKey 锁
   * @param identity 身份标识（保证锁不会被其他人释放）
   * @return
   */
  public boolean releaseLock(String lockKey, String identity){
    String luaScript =
        "if " +
        "  redis.call('get', KEYS[1]) == ARGV[1] " +
        "then " +
        "  return redis.call('del', KEYS[1]) " +
        "else " +
        "  return 0 " +
        "end";
    DefaultRedisScript<Boolean> redisScript = new DefaultRedisScript<>();
    redisScript.setResultType(Boolean.class);
    redisScript.setScriptText(luaScript);
    List<String> keys = new ArrayList<>();
    keys.add(lockKey);
    boolean result = redisTemplate.execute(redisScript, keys, identity);
    return result;
  }
}