Java註解如何基於Redission實現分散式鎖
阿新 • • 發佈:2020-01-16
這篇文章主要介紹了Java註解如何基於Redission實現分散式鎖,文中通過示例程式碼介紹的非常詳細,對大家的學習或者工作具有一定的參考學習價值,需要的朋友可以參考下
1、定義註解類
@Target({ ElementType.METHOD }) @Retention(RetentionPolicy.RUNTIME) @Documented public @interface DistributedLock { //鎖名稱 String lockName() default ""; //釋放時間 long releaseTime() default 5*1000; //時間單位 TimeUnit timeUnit() default TimeUnit.MILLISECONDS; }
2、定義切面攔截 DistributedLock 註解
@Aspect @Component @Slf4j public class DistributedLockAspect { @Autowired private RedissonClient redissonClient; //這裡需要修改對應的包名 @Pointcut("@annotation(com.utils.annotation.DistributedLock)") public void RlockAspect() { } @Around("RlockAspect()") public Object arround(ProceedingJoinPoint proceedingJoinPoint) throws Throwable { Object object = null; RLock lock = null; log.info("rlockAspect start "); try { DistributedLock rlockInfo = getRlockInfo(proceedingJoinPoint); String lockKey = getLocalKey(proceedingJoinPoint,rlockInfo); lock = redissonClient.getLock(lockKey); if (lock != null) { final boolean status = lock.tryLock(rlockInfo.releaseTime(),rlockInfo.timeUnit()); if (status) { object = proceedingJoinPoint.proceed(); } } else { log.info("未獲取到鎖:{}",lockKey); } } finally { // 當前執行緒獲取到鎖再釋放鎖 if (lock != null && lock.isHeldByCurrentThread()) { lock.unlock(); } } return object; } public DistributedLock getRlockInfo(ProceedingJoinPoint proceedingJoinPoint) { MethodSignature methodSignature = (MethodSignature) proceedingJoinPoint.getSignature(); return methodSignature.getMethod().getAnnotation(DistributedLock.class); } /** * 獲取redis lock key * * @param proceedingJoinPoint * @return */ public String getLocalKey(ProceedingJoinPoint proceedingJoinPoint,DistributedLock rlockInfo) { StringBuilder localKey = new StringBuilder("Rlock"); final Object[] args = proceedingJoinPoint.getArgs(); String businessNo = ""; // 如果沒有設定鎖值 if (StringUtils.isNotEmpty(rlockInfo.lockName())) { businessNo = rlockInfo.lockName(); } else { MethodSignature methodSignature = (MethodSignature) proceedingJoinPoint.getSignature(); Class[] parameters = methodSignature.getParameterTypes(); String methodName = methodSignature.getMethod().getName(); if (parameters != null) { for (int i = 0; i < parameters.length; i++) { Class parameter = parameters[i]; if (parameter.getSimpleName().equals("NDevice")) { NDevice de = (NDevice) args[i]; businessNo = de.getUuid() + methodName; } if (parameter.getSimpleName().equals("FrameBean")) { FrameBean de = (FrameBean) args[i]; businessNo = de.getColumn1() + methodName; } } // 如果沒有獲取到業務編號,則使用方法簽名 if (StringUtils.isEmpty(businessNo)) { businessNo = methodName; } } } return businessNo; } }
3、使用方法:在需要用分散式鎖的方法上面加 @DistributedLock 註解即可
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