手写redis@Cacheable注解 支持过期时间设置

• 原理解释 

友情链接  手写redis @ Cacheable注解参数java对象作为键值 

@Cacheable注解作用，将带有该注解方法的返回值存放到redis的的中;

使用方法在方法上使用@Cacheable（键=“测试+＃P0 + P1＃…”）

表示键值为测试+方法第一个参数+方法第二个参数，值为该方法的返回值。

以下源代码表示获取人员列表，Redis的中存放的关键值为’领袖’+ leaderGroupId + UUID + yearDetailId

 @Override @Cacheable(key="'leader'+#p0+#p1+#p2",value="leader") public List 
  
    listLeaders(String leaderGroupId, String uuid, String yearDetailId) { return sysIndexMapper.listLeaders(leaderGroupId, uuid, yearDetailId); } 
  

等同于

 @Override public List 
  
    listLeaders(String leaderGroupId, String uuid, String yearDetailId) { String key = "leader" + leaderGroupId + uuid + yearDetailId; // 判断缓存是否存在redis中 boolean hasKey = redisUtil.hasKey(key); if (hasKey) { //如果存在 返还redis中的值 Object leadersList = redisUtil.get(key); return (List 
   
     ) leadersList; } else { List 
    
      leadersQuotaDetailList = sysIndexMapper.listLeaders(leaderGroupId, uuid, yearDetailId); //将查询结果存放在redis中 redisUtil.set(key, leadersQuotaDetailList); return leadersQuotaDetailList; } } 
     
    
  

说白了就是在原方法的前面判断的关键值是否存在的Redis的中，如果存在就取内存中的值，如果不存在就查询数据库，将查询结果存放在Redis的的中。

• 实现方法

1. 使用代理模式，在方法执行前和执行后可以添加其他处理程序，本文采用springAOP +注解方式。
2. 集成redis，封装Redis工具类
3. 原版本不支持 过期时间 设置，本文将实现

• 源代码

缓存配置类RedisConfig

package com.huajie.config; import org.springframework.beans.factory.annotation.Value; import org.springframework.cache.CacheManager; import org.springframework.cache.annotation.CachingConfigurerSupport; import org.springframework.cache.annotation.EnableCaching; import org.springframework.cache.interceptor.KeyGenerator; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.data.redis.cache.RedisCacheManager; import org.springframework.data.redis.connection.RedisConnectionFactory; import org.springframework.data.redis.core.RedisTemplate; import org.springframework.data.redis.core.StringRedisTemplate; import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer; import org.springframework.data.redis.serializer.StringRedisSerializer; import com.fasterxml.jackson.annotation.JsonAutoDetect; import com.fasterxml.jackson.annotation.PropertyAccessor; import com.fasterxml.jackson.databind.ObjectMapper; / * Redis缓存配置类 */ @Configuration @EnableCaching public class RedisConfig extends CachingConfigurerSupport { @Value("${spring.redis.host}") private String host; @Value("${spring.redis.port}") private int port; @Value("${spring.redis.timeout}") private int timeout; // 自定义缓存key生成策略 @Bean public KeyGenerator keyGenerator() { return new KeyGenerator() { @Override public Object generate(Object target, java.lang.reflect.Method method, Object... params) { StringBuffer sb = new StringBuffer(); sb.append(target.getClass().getName()); sb.append(method.getName()); for (Object obj : params) { sb.append(obj.toString()); } return sb.toString(); } }; } // 缓存管理器 @Bean public CacheManager cacheManager(@SuppressWarnings("rawtypes") RedisTemplate redisTemplate) { RedisCacheManager cacheManager = new RedisCacheManager(redisTemplate); // 设置缓存过期时间 cacheManager.setDefaultExpiration(10000); return cacheManager; } @Bean public RedisTemplate 
  
    redisTemplate(RedisConnectionFactory factory) { RedisTemplate 
   
     template = new RedisTemplate 
    
      (); template.setConnectionFactory(factory); Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class); ObjectMapper om = new ObjectMapper(); om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY); om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL); jackson2JsonRedisSerializer.setObjectMapper(om); StringRedisSerializer stringRedisSerializer = new StringRedisSerializer(); // key采用String的序列化方式 template.setKeySerializer(stringRedisSerializer); // hash的key也采用String的序列化方式 template.setHashKeySerializer(stringRedisSerializer); // value序列化方式采用jackson template.setValueSerializer(jackson2JsonRedisSerializer); // hash的value序列化方式采用jackson template.setHashValueSerializer(jackson2JsonRedisSerializer); template.afterPropertiesSet(); return template; } private void setSerializer(StringRedisTemplate template) { @SuppressWarnings({ "rawtypes", "unchecked" }) Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class); ObjectMapper om = new ObjectMapper(); om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY); om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL); jackson2JsonRedisSerializer.setObjectMapper(om); template.setValueSerializer(jackson2JsonRedisSerializer); } } 
     
    
  

Redis的依赖引入，配置文件，工具类RedisUtil，网上几个版本都类似，本文参考以下版本传送门

https://www.cnblogs.com/zeng1994/p/03303c805731afc9aa9c60dbbd32a323.html

准备工作做好之后开始正式编写注解@Cacheable nextkey（）用做二级缓存本文中不会用到

nextKey用法详情> 设计模式（实战） – 责任链模式 <

创建的Java的注解@ExtCacheable  

package com.huajie.annotation; import java.lang.annotation.ElementType; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target; @Target({ ElementType.METHOD }) @Retention(RetentionPolicy.RUNTIME) public @interface ExtCacheable { String key() default ""; String nextKey() default ""; int expireTime() default 1800;//30分钟 } 

SpringAop切面CacheableAspect

package com.huajie.aspect; import java.lang.reflect.Method; import java.util.ArrayList; import java.util.List; 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.aspectj.lang.reflect.MethodSignature; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Component; import com.huajie.annotation.ExtCacheable; import com.huajie.utils.RedisUtil; / * redis缓存处理 * 不适用与内部方法调用(this.)或者private */ @Component @Aspect public class CacheableAspect { @Autowired private RedisUtil redisUtil; @Pointcut("@annotation(com.huajie.annotation.ExtCacheable)") public void annotationPointcut() { } @Around("annotationPointcut()") public Object doAround(ProceedingJoinPoint joinPoint) throws Throwable { // 获得当前访问的class Class 
   className = joinPoint.getTarget().getClass(); // 获得访问的方法名 String methodName = joinPoint.getSignature().getName(); // 得到方法的参数的类型 Class 
  [] argClass = ((MethodSignature) joinPoint.getSignature()).getParameterTypes(); Object[] args = joinPoint.getArgs(); String key = ""; int expireTime = 1800; try { // 得到访问的方法对象 Method method = className.getMethod(methodName, argClass); method.setAccessible(true); // 判断是否存在@ExtCacheable注解 if (method.isAnnotationPresent(ExtCacheable.class)) { ExtCacheable annotation = method.getAnnotation(ExtCacheable.class); key = getRedisKey(args,annotation); expireTime = getExpireTime(annotation); } } catch (Exception e) { throw new RuntimeException("redis缓存注解参数异常", e); } // 获取缓存是否存在 boolean hasKey = redisUtil.hasKey(key); if (hasKey) { return redisUtil.get(key); } else { //执行原方法（java反射执行method获取结果） Object res = joinPoint.proceed(); //设置缓存 redisUtil.set(key, res); //设置过期时间 redisUtil.expire(key, expireTime); return res; } } private int getExpireTime(ExtCacheable annotation) { return annotation.expireTime(); } private String getRedisKey(Object[] args,ExtCacheable annotation) { String primalKey = annotation.key(); //获取#p0...集合 List 
  
    keyList = getKeyParsList(primalKey); for (String keyName : keyList) { int keyIndex = Integer.parseInt(keyName.toLowerCase().replace("#p", "")); Object parValue = args[keyIndex]; primalKey = primalKey.replace(keyName, String.valueOf(parValue)); } return primalKey.replace("+","").replace("'",""); } // 获取key中#p0中的参数名称 private static List 
   
     getKeyParsList(String key) { List 
    
      ListPar = new ArrayList 
     
       (); if (key.indexOf("#") >= 0) { int plusIndex = key.substring(key.indexOf("#")).indexOf("+"); int indexNext = 0; String parName = ""; int indexPre = key.indexOf("#"); if(plusIndex>0){ indexNext = key.indexOf("#") + key.substring(key.indexOf("#")).indexOf("+"); parName = key.substring(indexPre, indexNext); }else{ parName = key.substring(indexPre); } ListPar.add(parName.trim()); key = key.substring(indexNext + 1); if (key.indexOf("#") >= 0) { ListPar.addAll(getKeyParsList(key)); } } return ListPar; } } 
      
     
    
  

业务模块使用方法

@Override @ExtCacheable(key = "Leaders+#p0+#p1+#p2") // 手机端获取领导人员列表 public List 
  
    listLeaders(String leaderGroupId, String uuid, String yearDetailId) { List 
   
     leadersQuotaDetailList = sysIndexMapper.listLeaders(leaderGroupId, uuid, yearDetailId); return leadersQuotaDetailList; } 
    
  

业务模块过期时间使用方法，5分钟过期

@Override @ExtCacheable(key = "mobileCacheFlag", expireTime = 60 * 5) public int cacheFlag() { int mobileCacheFlag = 1; mobileCacheFlag = sysIndexMapper.cacheFlag(); return mobileCacheFlag; }

Redis的的截图