缓存插件 EHCache 页面缓存CachingFilter

CacheManager cacheManager = CacheManager.create();
// 或者
cacheManager = CacheManager.getInstance();
// 或者
cacheManager = CacheManager.create("/config/ehcache.xml");
// 或者
cacheManager = CacheManager.create("http://localhost:8080/test/ehcache.xml");
cacheManager = CacheManager.newInstance("/config/ehcache.xml");
// .......
 
// 获取ehcache配置文件中的一个cache
Cache sample = cacheManager.getCache("sample");
// 获取页面缓存
BlockingCache cache = new BlockingCache(cacheManager.getEhcache("SimplePageCachingFilter"));
// 添加数据到缓存中
Element element = new Element("key", "val");
sample.put(element);
// 获取缓存中的对象，注意添加到cache中对象要序列化 实现Serializable接口
Element result = sample.get("key");
// 删除缓存
sample.remove("key");
sample.removeAll();
 
// 获取缓存管理器中的缓存配置名称
for (String cacheName : cacheManager.getCacheNames()) {
    System.out.println(cacheName);
}
// 获取所有的缓存对象
for (Object key : cache.getKeys()) {
    System.out.println(key);
}
 
// 得到缓存中的对象数
cache.getSize();
// 得到缓存对象占用内存的大小
cache.getMemoryStoreSize();
// 得到缓存读取的命中次数
cache.getStatistics().getCacheHits();
// 得到缓存读取的错失次数
cache.getStatistics().getCacheMisses();

protected boolean acceptsGzipEncoding(HttpServletRequest request) {
　　boolean ie6 = headerContains(request, "User-Agent", "MSIE 6.0");
　　boolean ie7 = headerContains(request, "User-Agent", "MSIE 7.0");
　　return acceptsEncoding(request, "gzip") || ie6 || ie7;
}

<?xml version="1.0" encoding="gbk"?>
<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="ehcache.xsd">
    <diskStore path="java.io.tmpdir"/>
 
    <defaultCache maxElementsInMemory="10000" eternal="false" timeToIdleSeconds="30" timeToLiveSeconds="30" overflowToDisk="false"/>
    <!-- 
        配置自定义缓存
        maxElementsInMemory：缓存中允许创建的最大对象数
        eternal：缓存中对象是否为永久的，如果是，超时设置将被忽略，对象从不过期。
        timeToIdleSeconds：缓存数据的钝化时间，也就是在一个元素消亡之前，
                    两次访问时间的最大时间间隔值，这只能在元素不是永久驻留时有效，
                    如果该值是 0 就意味着元素可以停顿无穷长的时间。
        timeToLiveSeconds：缓存数据的生存时间，也就是一个元素从构建到消亡的最大时间间隔值，
                    这只能在元素不是永久驻留时有效，如果该值是0就意味着元素可以停顿无穷长的时间。
        overflowToDisk：内存不足时，是否启用磁盘缓存。
        memoryStoreEvictionPolicy：缓存满了之后的淘汰算法。
    -->
    <cache name="SimplePageCachingFilter" 
        maxElementsInMemory="10000" 
        eternal="false"
        overflowToDisk="false" 
        timeToIdleSeconds="900" 
        timeToLiveSeconds="1800"
        memoryStoreEvictionPolicy="LFU" />
 
</ehcache>

package com.hoo.ehcache.filter;
 
import java.util.Enumeration;
import javax.servlet.FilterChain;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import net.sf.ehcache.CacheException;
import net.sf.ehcache.constructs.blocking.LockTimeoutException;
import net.sf.ehcache.constructs.web.AlreadyCommittedException;
import net.sf.ehcache.constructs.web.AlreadyGzippedException;
import net.sf.ehcache.constructs.web.filter.FilterNonReentrantException;
import net.sf.ehcache.constructs.web.filter.SimplePageCachingFilter;
import org.apache.commons.lang.StringUtils;
import org.apache.log4j.Logger;
 
/**
 * <b>function:</b> mobile 页面缓存过滤器
 * @author hoojo
 * @createDate 2012-7-4 上午09:34:30
 * @file PageEhCacheFilter.java
 * @package com.hoo.ehcache.filter
 * @project Ehcache
 * @blog http://blog.csdn.net/IBM_hoojo
 * @email hoojo_@126.com
 * @version 1.0
 */
public class PageEhCacheFilter extends SimplePageCachingFilter {
 
    private final static Logger log = Logger.getLogger(PageEhCacheFilter.class);
    
    private final static String FILTER_URL_PATTERNS = "patterns";
    private static String[] cacheURLs;
    
    private void init() throws CacheException {
        String patterns = filterConfig.getInitParameter(FILTER_URL_PATTERNS);
        cacheURLs = StringUtils.split(patterns, ",");
    }
    
    @Override
    protected void doFilter(final HttpServletRequest request,
            final HttpServletResponse response, final FilterChain chain)
            throws AlreadyGzippedException, AlreadyCommittedException,
            FilterNonReentrantException, LockTimeoutException, Exception {
        if (cacheURLs == null) {
            init();
        }
        
        String url = request.getRequestURI();
        boolean flag = false;
        if (cacheURLs != null && cacheURLs.length > 0) {
            for (String cacheURL : cacheURLs) {
                if (url.contains(cacheURL.trim())) {
                    flag = true;
                    break;
                }
            }
        }
        // 如果包含我们要缓存的url 就缓存该页面，否则执行正常的页面转向
        if (flag) {
            String query = request.getQueryString();
            if (query != null) {
                query = "?" + query;
            }
            log.info("当前请求被缓存：" + url + query);
            super.doFilter(request, response, chain);
        } else {
            chain.doFilter(request, response);
        }
    }
    
    @SuppressWarnings("unchecked")
    private boolean headerContains(final HttpServletRequest request, final String header, final String value) {
        logRequestHeaders(request);
        final Enumeration accepted = request.getHeaders(header);
        while (accepted.hasMoreElements()) {
            final String headerValue = (String) accepted.nextElement();
            if (headerValue.indexOf(value) != -1) {
                return true;
            }
        }
        return false;
    }
    
    /**
     * @see net.sf.ehcache.constructs.web.filter.Filter#acceptsGzipEncoding(javax.servlet.http.HttpServletRequest)
     * <b>function:</b> 兼容ie6/7 gzip压缩
     * @author hoojo
     * @createDate 2012-7-4 上午11:07:11
     */
    @Override
    protected boolean acceptsGzipEncoding(HttpServletRequest request) {
        boolean ie6 = headerContains(request, "User-Agent", "MSIE 6.0");
        boolean ie7 = headerContains(request, "User-Agent", "MSIE 7.0");
        return acceptsEncoding(request, "gzip") || ie6 || ie7;
    }
}

<!-- 缓存、gzip压缩核心过滤器 -->
<filter>
    <filter-name>PageEhCacheFilter</filter-name>
    <filter-class>com.hoo.ehcache.filter.PageEhCacheFilter</filter-class>
    <init-param>
        <param-name>patterns</param-name>
        <!-- 配置你需要缓存的url -->
        <param-value>/cache.jsp, product.action, market.action </param-value>
    </init-param>
</filter>
<filter-mapping>
    <filter-name>PageEhCacheFilter</filter-name>
    <url-pattern>*.action</url-pattern>
</filter-mapping>
<filter-mapping>
    <filter-name>PageEhCacheFilter</filter-name>
    <url-pattern>*.jsp</url-pattern>
</filter-mapping>