springboot整合redis+自定义注解+反射+aop实现分布式锁

1.定义注解

import java.lang.annotation.*;
import java.util.concurrent.TimeUnit;

/** @Author: best_liu
 * @Description:
 * @Date: 16:13 2023/9/4
 * @Param 
 * @return 
 **/
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.METHOD})
@Documented
public @interface RedisLock {
    String lockPrefix() default "";

    String lockKey() default "";

    //是否使用自定义过期时间,false->配置文件获取;true->自己指定过期时间
    boolean expireConfig() default true;

    long timeOut() default 30;

    TimeUnit timeUnit() default TimeUnit.SECONDS;
}

2.aop+redis

利用redis 的setIfAbsent()方法获取锁

import lombok.extern.slf4j.Slf4j;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Component;

import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.TimeUnit;

/** @Author: best_liu
 * @Description:
 * @Date: 16:13 2023/9/4
 * @Param 
 * @return 
 **/
@Aspect
@Component
@Slf4j
public class RedisLockAspect {
    private static final Integer Max_RETRY_COUNT = 3;
    private static final String LOCK_PRE_FIX = "lockPreFix";
    private static final String LOCK_KEY = "lockKey";
    private static final String TIME_OUT = "timeOut";
    private static final String EXPIRE_CONFIG = "expireConfig";

    @Value("${schedule.expire}")
    private long timeOut;

    @Autowired
    private RedisTemplate redisTemplate;

    @Pointcut("@annotation(com.mes.dispatch.annotation.redisLock.RedisLock)")
    public void redisLockAspect() {
    }

    @Around("redisLockAspect()")
    public void lockAroundAction(ProceedingJoinPoint proceeding) throws Exception {

        //获取注解中的参数
        Map<String, Object> annotationArgs = this.getAnnotationArgs(proceeding);
        String lockPrefix = (String) annotationArgs.get(LOCK_PRE_FIX);
        String key = (String) annotationArgs.get(LOCK_KEY);
        long expire = (long) annotationArgs.get(TIME_OUT);
        boolean expireConfig = (boolean) annotationArgs.get(EXPIRE_CONFIG);
        //分布式锁
        boolean lock = false;
        try {
            //如果返回true，说明key不存在，获取到锁
            lock = redisTemplate.opsForValue().setIfAbsent(key, lockPrefix);
            log.info("是否获取到锁:" + lock);
            if (lock) {
                log.info("获取到锁，开启定时任务！");
                //设置过期时间
                if (expireConfig) {
                    redisTemplate.expire(key, expire, TimeUnit.SECONDS);
                } else {
                    redisTemplate.expire(key, timeOut, TimeUnit.SECONDS);
                }

                proceeding.proceed();
            } else {
                log.info("其他系统正在执行此项任务");
                return;
            }
        } catch (Exception e) {
            e.printStackTrace();
        } catch (Throwable throwable) {
            throw new RuntimeException("分布式锁执行发生异常" + throwable.getMessage(), throwable);
        }
    }

    /**
     * 获取锁参数
     *
     * @param proceeding
     * @return
     */
    private Map<String, Object> getAnnotationArgs(ProceedingJoinPoint proceeding) {
        Class target = proceeding.getTarget().getClass();
        Method[] methods = target.getMethods();
        String methodName = proceeding.getSignature().getName();
        for (Method method : methods) {
            if (method.getName().equals(methodName)) {
                Map<String, Object> result = new HashMap<String, Object>();
                RedisLock redisLock = method.getAnnotation(RedisLock.class);
                result.put(LOCK_PRE_FIX, redisLock.lockPrefix());
                result.put(LOCK_KEY, redisLock.lockKey());
                result.put(TIME_OUT, redisLock.timeUnit().toSeconds(redisLock.timeOut()));
                result.put(EXPIRE_CONFIG, redisLock.expireConfig());
                return result;
            }
        }
        return null;
    }

}

3.使用