spring boot 自定义注解 实现本地锁

「爱情、让人受尽委屈。」 2022-12-19 16:17 264阅读 0赞

技术点

  1. AOP
  2. 注解声明
  3. 自动配置

声明注解

  1. import java.lang.annotation.*;
  3. @Target(ElementType.METHOD)
  4. @Retention(RetentionPolicy.RUNTIME)
  5. @Documented
  6. @Inherited
  7. public @interface LocalLock { 
  8.     String key() default "";
  9. }

key为锁标识

AOP 实现注解

  1. import cn.hutool.cache.Cache;
  2. import cn.hutool.cache.CacheUtil;
  3. import cn.hutool.core.date.DateUnit;
  4. import cn.hutool.core.util.NumberUtil;
  5. import cn.hutool.core.util.ReflectUtil;
  6. import cn.hutool.core.util.StrUtil;
  7. import com.alibaba.fastjson.JSON;
  8. import com.guodun.aiosign.tools.lock.LocalLock;
  9. import lombok.extern.slf4j.Slf4j;
  10. import org.aspectj.lang.ProceedingJoinPoint;
  11. import org.aspectj.lang.annotation.Around;
  12. import org.aspectj.lang.annotation.Aspect;
  13. import org.aspectj.lang.reflect.MethodSignature;
  14. import org.springframework.context.annotation.Configuration;
  15. import org.springframework.util.StringUtils;
  17. import java.lang.reflect.Method;
  19. @Aspect
  20. @Configuration
  21. @Slf4j
  22. public class LocalLockInterceptor { 
  23.     private static Cache<String, String> lockCache = CacheUtil.newLFUCache(200, DateUnit.SECOND.getMillis() * 10);
  24.     @Around("@annotation(com.guodun.aiosign.tools.lock.LocalLock)")
  25.     public Object interceptor(ProceedingJoinPoint pjp) { 
  26.         MethodSignature signature = (MethodSignature) pjp.getSignature();
  27.         Method method = signature.getMethod();
  28.         LocalLock localLock = method.getAnnotation(LocalLock.class);
  29.         String key = getKey(localLock.key(), pjp.getArgs());
  30.         if (!StringUtils.isEmpty(key)) { 
  31.             if (lockCache.containsKey(key)) { 
  32.                 log.debug("发生死锁 ： {} ",key);
  33.                 checkLock(key);
  34.             }else { 
  35.                 lockCache.put(key, key);
  36.             }
  37.         }
  38.         try { 
  39.             return pjp.proceed();
  40.         } catch (Throwable throwable) { 
  41.             throw new RuntimeException("服务器异常");
  42.         } finally { 
  43.             // 请求结束后解除锁
  44.            if (!StringUtils.isEmpty(key)) lockCache.remove(key);
  45.         }
  46.     }
  47.     private void checkLock(String key)  { 
  48.         try { 
  49.             for (int i = 0; i < 20; i++) { 
  50.                 if (!lockCache.containsKey(key)) return;
  51.                 Thread.sleep(500);
  52.             }
  53.         }catch (InterruptedException e) { 
  54.             e.printStackTrace();
  55.         }
  56.         if (lockCache.containsKey(key))  throw new RuntimeException("请勿重复请求");
  57.     }
  58.     private String getKey(String keyExpress, Object[] args) { 
  59.         String[] keys = StrUtil.splitToArray(keyExpress,'.');
  60.         log.debug("参数 {} ", JSON.toJSONString(keys));
  61.         if (keys.length>0&&args.length>0){ 
  62.             String args_str = keys[0];
  63.             if(!NumberUtil.isInteger(args_str)) return null;
  64.             int args_index = Integer.valueOf(args_str);
  65.             if (args_index>args.length)return null;
  66.             if(keys.length<2) { 
  67.                 log.info("value : {} ",args[args_index-1].toString());
  68.                 return args[args_index-1].toString();
  69.             }
  70.             Object value = ReflectUtil.getFieldValue(args[args_index-1],keys[1]);
  71.             log.info("value : {} ",value.toString());
  72.             return value.toString();
  73.         }
  74.         return null;
  75.     }
  76. }

自动配置（spring boot）

在这里插入图片描述

  1. #配置自定义Starter的自动化配置
  2. org.springframework.boot.autoconfigure.EnableAutoConfiguration=com.keepgoon.tools.lock.local.LocalLockInterceptor

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