J2EE 缓存使用

最新推荐文章于 2021-02-23 23:37:13 发布

anghlq

最新推荐文章于 2021-02-23 23:37:13 发布

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分类专栏： java 文章标签： object null string class cache exception

本文链接：https://blog.youkuaiyun.com/anghlq/article/details/7366337

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3 篇文章

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1. 编程方式

get-and-set，可以针对到每条缓存的存放时间

import net.sf.ehcache.Cache;
import net.sf.ehcache.Element;

import java.util.concurrent.Callable;

public class CacheWrap {
	private Cache ehcache;
	public void set(String key, Object value, int expire) {		
		Element elem = new Element(key, value);
		if (expire!=0)
		{
			elem.setTimeToLive(expire);
		}
		getEhcache().put(elem, true);
	}
	public Object get(String key) {
		Element elem = getEhcache().get(key);
		return (null != elem) ? elem.getObjectValue() : null;
	}
	public Object get(String key, Callable refreshSource, int expire) { 

		Element elem = getEhcache().get(key);
		Object value = (null != elem) ? elem.getObjectValue() : null;
		if (null == value && null != refreshSource) {
			try {
				value = refreshSource.call();
				if (null != value) {
					Element newElem = new Element(key, value);
					newElem.setTimeToLive(expire);
					getEhcache().put(newElem, true);
				} 
			} catch (Exception ex) { 
				
			}
		}
		return value;
	}
	public Cache getEhcache() {
		return ehcache;
	}
	public void setEhcache(Cache ehcache) {
		this.ehcache = ehcache;
	}
}

2. 注解方式

所有的缓存的时间都是根据配置决定

org.springframework.cache.annotation.Cacheable;

@Cacheable(value="tyacCache",key="'srvlist_'+#user_id+'_'+#appName")
public List<Tyacservice> getList(final Long user_id, String appName)....

3. 对应的spring和ehcache配置

ehcache.xml

<?xml version="1.0" encoding="UTF-8"?>
<ehcache>
<defaultCache maxElementsInMemory="10000" eternal="false" timeToIdleSeconds="600"
timeToLiveSeconds="600" overflowToDisk="false" memoryStoreEvictionPolicy="LRU"/>
<cache name="tyacCache" maxElementsInMemory="10000" eternal="false"
overflowToDisk="false" timeToIdleSeconds="60" timeToLiveSeconds="60"
memoryStoreEvictionPolicy="LRU"/>
</ehcache>

applicationContext.xml

#1相关

<bean id="ehCache" class="org.springframework.cache.ehcache.EhCacheFactoryBean">
<property name="cacheManager">
<ref local="cacheManagerFactory"/>
</property>
<property name="cacheName">
<value>tyacCache</value>
</property>
</bean>

#2相关