手寫redis@Cacheable註解 支持過期時間設置方式
原理解釋
友情鏈接 手寫redis @ Cacheable註解參數java對象作為鍵值
@Cacheable註解作用,將帶有該註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(鍵=“測試+#P0 + P1#…”)
表示鍵值為測試+方法第一個參數+方法第二個參數,值為該方法的返回值。
以下源代碼表示獲取人員列表,Redis的中存放的關鍵值為'領袖'+ leaderGroupId + UUID + yearDetailId
@Override @Cacheable(key="'leader'+#p0+#p1+#p2",value="leader") public List<Leader> listLeaders(String leaderGroupId, String uuid, String yearDetailId) { return sysIndexMapper.listLeaders(leaderGroupId, uuid, yearDetailId); }
等同於
@Override public List<Leader> listLeaders(String leaderGroupId, String uuid, String yearDetailId) { String key = "leader" + leaderGroupId + uuid + yearDetailId; // 判斷緩存是否存在redis中 boolean hasKey = redisUtil.hasKey(key); if (hasKey) { //如果存在 返還redis中的值 Object leadersList = redisUtil.get(key); return (List<Leader>) leadersList; } else { List<Leader> leadersQuotaDetailList = sysIndexMapper.listLeaders(leaderGroupId, uuid, yearDetailId); //將查詢結果存放在redis中 redisUtil.set(key, leadersQuotaDetailList); return leadersQuotaDetailList; } }
說白瞭就是在原方法的前面判斷的關鍵值是否存在的Redis的中,如果存在就取內存中的值,如果不存在就查詢數據庫,將查詢結果存放在Redis的的中。
實現方法
- 使用代理模式,在方法執行前和執行後可以添加其他處理程序,本文采用springAOP +註解方式。
- 集成redis,封裝Redis工具類
- 原版本不支持 過期時間 設置,本文將實現
源代碼
緩存配置類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緩存配置類 */ @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; // 自定義緩存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(); } }; } // 緩存管理器 @Bean public CacheManager cacheManager(@SuppressWarnings("rawtypes") RedisTemplate redisTemplate) { RedisCacheManager cacheManager = new RedisCacheManager(redisTemplate); // 設置緩存過期時間 cacheManager.setDefaultExpiration(10000); return cacheManager; } @Bean public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) { RedisTemplate<String, Object> template = new RedisTemplate<String, Object>(); 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的依賴引入,配置文件,工具類RedisUtil,網上幾個版本都類似,本文參考以下版本傳送門
https://www.jb51.net/article/233562.htm
準備工作做好之後開始正式編寫註解@Cacheable nextkey()用做二級緩存本文中不會用到
nextKey用法詳情> 設計模式(實戰) – 責任鏈模式 <
創建的Java的註解@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分鐘 }
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緩存處理 * 不適用與內部方法調用(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 { // 獲得當前訪問的class Class<?> className = joinPoint.getTarget().getClass(); // 獲得訪問的方法名 String methodName = joinPoint.getSignature().getName(); // 得到方法的參數的類型 Class<?>[] argClass = ((MethodSignature) joinPoint.getSignature()).getParameterTypes(); Object[] args = joinPoint.getArgs(); String key = ""; int expireTime = 1800; try { // 得到訪問的方法對象 Method method = className.getMethod(methodName, argClass); method.setAccessible(true); // 判斷是否存在@ExtCacheable註解 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緩存註解參數異常", e); } // 獲取緩存是否存在 boolean hasKey = redisUtil.hasKey(key); if (hasKey) { return redisUtil.get(key); } else { //執行原方法(java反射執行method獲取結果) Object res = joinPoint.proceed(); //設置緩存 redisUtil.set(key, res); //設置過期時間 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(); //獲取#p0...集合 List<String> 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("'",""); } // 獲取key中#p0中的參數名稱 private static List<String> getKeyParsList(String key) { List<String> ListPar = new ArrayList<String>(); 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; } }
業務模塊使用方法
@Override @ExtCacheable(key = "Leaders+#p0+#p1+#p2") // 手機端獲取領導人員列表 public List<Leader> listLeaders(String leaderGroupId, String uuid, String yearDetailId) { List<Leader> leadersQuotaDetailList = sysIndexMapper.listLeaders(leaderGroupId, uuid, yearDetailId); return leadersQuotaDetailList; }
業務模塊過期時間使用方法,5分鐘過期
@Override @ExtCacheable(key = "mobileCacheFlag", expireTime = 60 * 5) public int cacheFlag() { int mobileCacheFlag = 1; mobileCacheFlag = sysIndexMapper.cacheFlag(); return mobileCacheFlag; }
Redis的的截圖
以上為個人經驗,希望能給大傢一個參考,也希望大傢多多支持WalkonNet。
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