SpringBoot2.0 @Cacheable 添加超时策略

SpringBoot2.0 @Cacheable 添加超时策略

　　逻辑比较简单，废话不多说，直接进入正题：

　　需求：SpringBoot 利用注解使缓存支持过期时间 （同@Cacheable @CachePut 等注解用法）

　　第一步：新建注解CacheExpire 

 @Retention(RetentionPolicy.RUNTIME)
 @Target({ElementType.TYPE, ElementType.METHOD})
 public @interface CacheExpire {

     /**
      * 缓存过期时间
      */
     long expire() default 0;

     /**
      * 仅当采用expire字段设置过期时间时生效
      */
     TimeUnit timeUnit() default TimeUnit.SECONDS;

     /**
      * 利用cron设置过期时间
      */
     String cron() default "";

 }

　　

　　第二步：扩展CacheInterceptor拦截器

 public class CacheExpireInterceptor extends CacheInterceptor {

     private final StringRedisTemplate template;

     public CacheExpireInterceptor(StringRedisTemplate template) {
         this.template = template;
     }

     @Override
     public Object invoke(MethodInvocation invocation) throws Throwable {
         Object invoke = super.invoke(invocation);
         setExpire(invocation);
         return invoke;
     }

     public void setExpire(MethodInvocation invocation) {
         try {
             Method method = invocation.getMethod();
             CacheExpire expire = method.getAnnotation(CacheExpire.class);
             if (expire != null && (expire.expire() > 0 || !StringUtils.isEmpty(expire.cron()))) {
                 Cacheable cacheable = method.getAnnotation(Cacheable.class);
                 Object key = getKeyGenerator().generate(invocation.getThis(), method, invocation.getArguments());
                 Set<String> names = new TreeSet<>();
                 names.addAll(Arrays.asList(cacheable.cacheNames()));
                 names.addAll(Arrays.asList(cacheable.value()));
                 for (String name : names) {
                     String tag = name + "::" + key;
                     if (expire.expire() > 0) {
                         template.expire(tag, expire.expire(), expire.timeUnit());
                     } else if (!StringUtils.isEmpty(expire.cron())) {
                         CronTrigger trigger = TriggerBuilder.newTrigger().withSchedule(CronScheduleBuilder.cronSchedule(expire.cron())).build();
                         Date date = new Date();
                         long time = trigger.getFireTimeAfter(date).getTime() - date.getTime();
                         if (time > 0) {
                             template.expire(tag, time, TimeUnit.MILLISECONDS);
                         }
                     }
                 }
             }
         } catch (Exception e) {
             e.printStackTrace();
         }
     }

 }

　　第三步：扩展ProxyCachingConfiguration配置文件

 @Configuration
 public class ProxyCachingExpireConfiguration extends ProxyCachingConfiguration {

     private final StringRedisTemplate template;

     public ProxyCachingExpireConfiguration(StringRedisTemplate template) {
         this.template = template;
     }

     @Bean
     @Override
     public CacheInterceptor cacheInterceptor() {
         CacheInterceptor interceptor = new CacheExpireInterceptor(template);
         interceptor.configure(this.errorHandler, this.keyGenerator, this.cacheResolver, this.cacheManager);
         interceptor.setCacheOperationSource(this.cacheOperationSource());
         return interceptor;
     }
 }

　　第四步：新建Service开始使用

 @Service
 public class TsetService {

     @CacheExpire(expire = 20)
     @Cacheable(value = "test")
     public Object get(Long id) {
         return System.currentTimeMillis();
     }

 }

　　第五步：Postman调用

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