springboot：自定义缓存注解，实现生存时间需求

package com.test.entity.util.annotation.cache;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 MyCacheable { /**
* 缓存key
*
* @return
*/
String key(); /**
* 是否缓存空值
*
* @return
*/
boolean cacheNull() default false; /**
* 生存时间，单位是秒，默认为-1(永不过期)
*
* @return
*/
int ttl() default -1; /**
* 生存状态
*
* true:每访问一次，将刷新存活时间
*
* false:不刷新存活时间，时间一到就清除
*
* @return
*/
boolean state() default true;
}

package com.test.service.aop;import java.lang.reflect.Method;import org.apache.commons.lang3.StringUtils;
import org.aspectj.lang.JoinPoint;
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.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cache.annotation.CacheConfig;
import org.springframework.context.annotation.Lazy;
import org.springframework.expression.Expression;
import org.springframework.expression.ExpressionParser;
import org.springframework.expression.spel.standard.SpelExpressionParser;
import org.springframework.expression.spel.support.StandardEvaluationContext;
import org.springframework.stereotype.Component;import com.test.entity.util.annotation.cache.MyCacheable;
import com.test.util.redis.RedisUtil;@Aspect
@Component
@Lazy(false)
public class AspectCacheable { private Logger log = LoggerFactory.getLogger(AspectCacheable.class); @Autowired
private RedisUtil redisUtil; /**
* 定义切入点
*/
@Pointcut("@annotation(com.test.entity.util.annotation.cache.MyCacheable)")
private void cut() {
// do nothing
} /**
* 环绕通知
*/
@Around("cut()")
public Object around(ProceedingJoinPoint joinPoint) throws Throwable {
// 读取缓存注解
MyCacheable myCacheable = this.getMethodAnnotation(joinPoint);
// 读取类注解
CacheConfig cacheConfig = this.getClassAnnotation(joinPoint);
// 获取方法传入参数
Object[] params = joinPoint.getArgs();
// 获得解释之后的key
String strKey = this.getKey(cacheConfig, myCacheable, params);
log.debug("解释之后的key:{}", strKey);
// 在方法执行前判断是否存在缓存
Object object = this.getCache(strKey, myCacheable.state(), myCacheable.ttl());
if (object == null) {
// 创建缓存
object = this.createCache(joinPoint, strKey, myCacheable);
}
return object;
} /**
* 获取方法中声明的注解
*
* @param joinPoint
* @return
* @throws NoSuchMethodException
*/
private MyCacheable getMethodAnnotation(JoinPoint joinPoint) throws NoSuchMethodException {
// 获取方法名
String methodName = joinPoint.getSignature().getName();
// 反射获取目标类
Class<?> targetClass = joinPoint.getTarget().getClass();
// 拿到方法对应的参数类型
Class<?>[] parameterTypes = ((MethodSignature) joinPoint.getSignature()).getParameterTypes();
// 根据类、方法、参数类型（重载）获取到方法的具体信息
Method objMethod = targetClass.getMethod(methodName, parameterTypes);
// 拿到方法定义的注解信息
return objMethod.getDeclaredAnnotation(MyCacheable.class);
} /**
* 获取类中声明的注解
*
* @param joinPoint
* @return
* @throws NoSuchMethodException
*/
private CacheConfig getClassAnnotation(JoinPoint joinPoint) throws NoSuchMethodException {
// 反射获取目标类
Class<?> targetClass = joinPoint.getTarget().getClass();
return targetClass.getDeclaredAnnotation(CacheConfig.class);
} /**
* 读取现有缓存
*
* @param key
* 实际key,非key表达式
* @param state
* 是否刷新存活时间
* @return
*/
private Object getCache(String key, boolean state, int ttl) {
Object obj = redisUtil.get(key);
if (obj != null && state && ttl != -1) {
// 存在缓存&每次访问重置TTL&非永不过期
// 每次访问后重新刷新TTL，还原为原来值
redisUtil.expire(key, ttl);
}
return obj;
} /**
* 解析key表达式，得到实际的key
*
* @param myCacheable
* @param params
* @return
*/
private String getKey(CacheConfig cacheConfig, MyCacheable myCacheable, Object[] params) {
ExpressionParser parser = new SpelExpressionParser();
StandardEvaluationContext ctx = new StandardEvaluationContext();
// 获得原始key的表达式
String strSourceKey = myCacheable.key();
int intSeq = -1;
String strSearchSeq = null;
int intStartPos = 0;
// 用SPEL解析表达式
while (++intSeq < params.length) {
strSearchSeq = "#p" + intSeq;
intStartPos = StringUtils.indexOf(strSourceKey, strSearchSeq, intStartPos);
if (intStartPos < 0) {
break;
} else {
ctx.setVariable("p" + intSeq, params[intSeq]);
}
}
// 执行表达式
Expression expression = parser.parseExpression(strSourceKey);
String strKey = expression.getValue(ctx).toString();
// 拼接上缓存名称,spring cache会加上前缀,是在CacheConfig中配置的。
if (cacheConfig != null) {
strKey = cacheConfig.cacheNames()[0] + ":" + strKey;
}
return strKey;
} /**
* 创建缓存
*
* @param joinPoint
* @param strKey
* @param myCacheable
* @return
* @throws Throwable
*/
private Object createCache(ProceedingJoinPoint joinPoint, String strKey, MyCacheable myCacheable) throws Throwable {
// 没有缓存则执行目标方法
// 获取目标方法的名称
String methodName = joinPoint.getSignature().getName();
log.debug("目标执行方法:{}", methodName);
// 执行源方法
Object object = joinPoint.proceed();
if (object != null) {
// 设置缓存
redisUtil.set(strKey, object);
redisUtil.expire(strKey, myCacheable.ttl());
} else {
// 判断是否缓存null
if (myCacheable.cacheNull()) {
redisUtil.set(strKey, object);
}
}
return object;
}
}

@Service
@Transactional
public class ServiceImplCoach implements ServiceCoach { private Logger log = LoggerFactory.getLogger(ServiceImplCoach.class); @Autowired
private DaoCoach daoCoach;

@MyCacheable(key = "'coachnum:'+#p0", ttl = 3600, state = false)

@Override
public EntityCoach select(String coachnum) {
EntityCoach entityCoach = null;
if (StringUtils.isNotBlank(coachnum)) {
try {
entityCoach = daoCoach.selectByPrimaryKey(coachnum);
} catch (Exception e) {
log.error("查询教练员发生错误:{}", e);
}
} else {
log.info("查询教练员,输入不符合要求");
}
return entityCoach;
} @CacheEvict(key = "'coachnum:'+#p0")
@Override
public EntityRes delete(String coachnum) throws Exception {
EntityRes entityRes = new EntityRes();
log.debug("删除教练员,id={}", coachnum);
if (StringUtils.isBlank(coachnum)) {
log.info("删除教练员，输入不符合要求。");
entityRes.setErrorcode(INVALID);
} else {
daoCoach.deleteByPrimaryKey(coachnum);
entityRes.setErrorcode(CODE_SUCC);
}
return entityRes;
}}