Spring @Cacheable指定失效时间实例

更新时间:2023-04-04 05:12:25 阅读：评论：0

spring @cacheable指定失效时间

新版本配置

@configuration@enablecachingpublic class rediscacheconfig {    @bean    public rediscachemanagerbuildercustomizer rediscachemanagerbuildercustomizer() {        return (builder) -> {            for (map.entry<string, duration> entry : rediscachename.getcachemap().entryt()) {                builder.withcacheconfiguration(entry.getkey(),                        rediscacheconfiguration.defaultcacheconfig().entryttl(entry.getvalue()));            }        };    }     public static class rediscachename {         public static final string cache_10min = "cache_10min";         @getter        private static final map<string, duration> cachemap;         static {            cachemap = immutablemap.<string, duration>builder().put(cache_10min, duration.ofconds(10l)).build();        }     }  }

老版本配置

interface cachenames{    string cache_15mins = "sssss:cache:15m";        /** 30分钟缓存组 */    string cache_30mins = "sssss:cache:30m";        /** 60分钟缓存组 */    string cache_60mins = "sssss:cache:60m";        /** 180分钟缓存组 */    string cache_180mins = "sssss:cache:180m";} @component public class rediscachecustomizer            implements cachemanagercustomizer<rediscachemanager> {        /** cachemanager缓存自定义初始化比较早，尽量不要@autowired 其他spring 组件 */        @override        public void customize(rediscachemanager cachemanager) {            // 自定义缓存名对应的过期时间            map<string, long> expires = immutablemap.<string, long>builder()                  影视学校  .put(cachenames.cache_15mins, timeunit.minutes.toconds(15))                    .put(cachenames.cache_30mins, timeunit.minutes.toconds(30))                    .put(cachenames.cache_60mins, timeunit.minutes.toconds(60))                    .put(cachenames.cache_180mins, timeunit.minutes.toconds(180)).build();            // spring cache是根据cache name查找缓存过期时长的，如果找不到，则使用默认值            cachemanager.tdefaultexpiration(timeunit.minutes.toconds(30));            cachemanager.texpires(expires);        }    }    @cacheable(key = "key", cachenames = cachenames.cache_15mins)    public string demo2(string key) {        return "abc" + key;  }

@cacheable缓存失效时间策略默认实现及扩展

之前对spring缓存的理解是每次设置缓存之后，重复请求会刷新缓存时间，但是问题排查阅读源码发现，跟自己的理解大相径庭。所有的你以为都仅仅是你以为！！！！

背景

目前项目使用的spring缓存，主要是cachemanager、cache以及@cacheable注解，spring现有的缓存注解暑假里的新鲜事作文无法单独设置每一个注解的失效时间，spring官方给的解释：spring cache是一个抽象而不是一个缓存实现方案。

因此对于缓存失效时间（ttl）的策略依赖于底层缓存中间件，官方给举例：concurrentmap是不支持失效时间的，而redis是支持失效时间的。

spring cache redis实现

spring缓存注解@cacheable底层的cachemanager与cache如果使用redis方案的话，首次设置缓存数据之后，每次重复请求相同方法读取缓存并不会刷新失效时间，这是spring的默认行为（受一些缓存影响，一直以为每次读缓存也会刷新缓存失效时间）。

可以参见源码：

org.springframework.cache.interceptor.cacheaspectsupport#execute(org.springframework.cache.interceptor.cacheoperationinvoker, java.lang.reflect.method, org.springfram并集和交集的区别ework.cache.interceptor.cacheaspectsupport.cacheoperationcontexts)

private object execute(final cacheoperationinvoker invoker, method method, cacheoperationcontexts contexts) {// special handling of synchronized invocationif (contexts.issynchronized()) {cacheoperationcontext context = contexts.get(cacheableoperation.class).iterator().next();if (isconditionpassing(context, cacheoperationexpressionevaluator.no_result)) {object key = generatekey(context, cacheoperationexpressionevaluator.no_result);cache cache = context.getcaches().iterator().next();try {return wrapcachevalue(method, cache.get(key, () -> unwrapreturnvalue(invokeoperation(invoker))));}catch (cache.valueretrievalexception ex) {// the invoker wraps any throwable in a throwablewrapper instance so we// can just make sure that one bubbles up the stack.throw (cacheoperationinvoker.throwablewrapper) ex.getcau();}}el {// no caching required, only call the underlying methodreturn invokeoperation(invoker);}}  // process any early evictionsprocesscacheevicts(contexts.get(cacheevictoperation.class), true,cacheoperationexpressionevaluator.no_result); // check if we have a cached item matching the conditionscache.valuewrapper cachehit = findcacheditem(contexts.get(cacheableoperation.class)); // collect puts from any @cacheable miss, if no cached item is foundlist<cacheputrequest> cacheputrequests = new linkedlist<>();if (cachehit == null) {collectputrequests(contexts.get(cacheableoperation.class),cacheoperationexpressionevaluator.no_result, cacheputrequests);} object cachevalue;object returnvalue; if (cachehit != null && !hascacheput(contexts)) {// if there are no put requests, just u the cache hitcachevalue = cachehit.get();returnvalue = wrapcachevalue(method, cachevalue);}el {// invoke the method if we don't have a cache hitreturnvalue = invokeoperation(invoker);cachevalue = unwrapreturnvalue(returnvalue);} // collect any explicit @cacheputscollectputrequests(contexts.get(cacheputoperation.class), cachevalue, cacheputrequests); // process any collected put requests, either from @cacheput or a @cacheable missfor (cacheputrequest cacheputrequest : cacheputrequests国民教育) {cacheputrequest.apply假如我是武松(cachevalue);} // process any late evictionsprocesscacheevicts(contexts.get(cacheevictoperation.class), fal, cachevalue); return returnvalue;}

因此如果我们需要自行控制缓存失效策略，就可能需要一些开发工作，具体如下。