1.引入依賴包
<dependency>
<groupId>net.sf.ehcache</groupId>
<artifactId>ehcache-core</artifactId>
<version>2.5.1</version>
</dependency>
2.配置
以下配置是用spring自定義的一個簡單的緩存管理器
<cache:annotation-driven/>
<!-- generic cache manager -->
<bean id="cacheManager"
class="org.springframework.cache.support.SimpleCacheManager">
<property name="caches">
<set>
<bean
class="org.springframework.cache.concurrent.ConcurrentMapCacheFactoryBean"
p:name="default" />
<bean
class="org.springframework.cache.concurrent.ConcurrentMapCacheFactoryBean"
p:name="nurseCache" />
</set>
</property>
</bean>
可以用第三方的 如ehcache ehcache.xml配置
<?xml version="1.0"?>
<ehcache xmlms:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="ehcache.xsd">
<diskStore path="cache" />
<!-- <defaultCache maxElementsInMemory="10000" eternal="false" -->
<!-- timeToIdleSeconds="30" timeToLiveSeconds="30" overflowToDisk="false" /> -->
<cache name="nurseCache" maxElementsInMemory="10000" eternal="false"
timeToIdleSeconds="300" timeToLiveSeconds="10" overflowToDisk="false"
memoryStoreEvictionPolicy="LFU" />
<cache name="bdHospitalCache" maxElementsInMemory="10000" eternal="false"
timeToIdleSeconds="300" timeToLiveSeconds="10" overflowToDisk="false"
memoryStoreEvictionPolicy="LFU" />
<cache name="dicCache" maxElementsInMemory="10000" eternal="false"
timeToIdleSeconds="300" timeToLiveSeconds="360000" overflowToDisk="false"
memoryStoreEvictionPolicy="LFU" />
<cache name="bannerCache" maxElementsInMemory="10000" eternal="false"
timeToIdleSeconds="300" timeToLiveSeconds="36000" overflowToDisk="false"
memoryStoreEvictionPolicy="LFU" />
<cache name="dicItemCache" maxElementsInMemory="10000" eternal="false"
timeToIdleSeconds="300" timeToLiveSeconds="10" overflowToDisk="false"
memoryStoreEvictionPolicy="LFU" />
<cache name="queryDicById" maxElementsInMemory="10000" eternal="false"
timeToIdleSeconds="300" timeToLiveSeconds="10" overflowToDisk="false"
memoryStoreEvictionPolicy="LFU" />
<cache name="getCustomerInfo" maxElementsInMemory="10000" eternal="false"
timeToIdleSeconds="300" timeToLiveSeconds="10" overflowToDisk="false"
memoryStoreEvictionPolicy="LFU" />
</ehcache>
spring文件配置
<cache:annotation-driven cache-manager="ehcacheManager"/>
<!-- cacheManager工廠類,指定ehcache.xml的位置 -->
<bean id="ehcacheManagerFactory" class="org.springframework.cache.ehcache.EhCacheManagerFactoryBean">
<property name="configLocation" value="classpath:ehcache.xml" />
</bean>
<!-- 聲明cacheManager -->
<bean id="ehcacheManager" class="org.springframework.cache.ehcache.EhCacheCacheManager">
<property name="cacheManager" ref="ehcacheManagerFactory" />
</bean>
3.編碼
//存到緩存中的key值是查詢參數
@Cacheable(value="nurseCache",key="#idItems")
public List<Nurse> queryNurseListByIdCol(String idItems) {
System.out.println("查詢數據庫");
System.out.println(idItems);
if(idItems == null || "".equals(idItems)){
return null;
}
String url = apiQueryNursesByIds+"?idItems="+idItems;
String result = HttpUtil.sendGet(url, "utf-8");
System.out.println(result);
HttpNurseListResult resultList = JSON.parseObject(result, HttpNurseListResult.class);
if(resultList == null){
return null;
}
int success = resultList.getSuccess();
if(success != 1){
return null;
}
return resultList.getData();
}
多值組合key,比如下面例子代碼中的bannerDtoRpc對象中的city屬性與position屬性聯合組成key
@Cacheable(value="bannerCache",key="#bannerDtoRpc.city.concat(T(String).valueOf(#bannerDtoRpc.position))")
public List<BannerRpc> queryCustomerBanners(BannerDtoRpc bannerDtoRpc) {
System.out.println("實際查詢");
return bannerRpcDao.queryCustomerBanners(bannerDtoRpc);
}
在使用緩存時,如果我們對數據增,刪,改操作時,這個時候需要及時的清理相應key裏面的緩存,
在spring中可以直接用 @CacheEvict 註解,因爲我們的緩存並沒有獨立開來,例如用redis來管理緩存
這個時候對數據的增,刪,改可能在其他系統操作,則不能用這個註解,可以通過編碼的方式對外提供緩存
清理的接口
private CacheManager ehcacheManager;
@Override
public ResponseVoRpc clearCache(@Param("cacheName")String cacheName,@Param("request")HttpServletRequest request) {
ResponseVoRpc resp = new ResponseVoRpc();
ServletContext servletContext = request.getServletContext();
WebApplicationContext ctx = WebApplicationContextUtils.getWebApplicationContext(servletContext);
ehcacheManager = (CacheManager)ctx.getBean("ehcacheManager" );
Cache cache = ehcacheManager.getCache(cacheName);
if(cache==null){
resp.setCode(ResponseVoRpc.CODE_COMMON_SUCCESS);
resp.setCodeMsg(ResponseVoRpc.CODE_MAP.get(ResponseVoRpc.CODE_COMMON_SUCCESS));
return resp;
}
cache.clear();
resp.setCode(ResponseVoRpc.CODE_COMMON_SUCCESS);
resp.setCodeMsg(ResponseVoRpc.CODE_MAP.get(ResponseVoRpc.CODE_COMMON_SUCCESS));
return resp;
}
注意: