Ehcache web cahce 缓存改良版

浏览数：37 / 时间：2015年06月09日

java 代码：

package net.sf.ehcache.constructs.web.filter;

import java.util.Enumeration;

import javax.servlet.FilterChain;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.lang.StringUtils;

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;

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, ",");
    }

    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;
                }
            }
        }
        if(!flag)
        {
           //压缩所有ｊｓ与ｃｓｓ文件及所有静态页
           if(url != null && (url.endsWith(".js") || url.endsWith(".css") || url.endsWith(".html") || url.endsWith(".htm")))
           {
               flag = true;
           }
        }
        // 若是包含我们要缓存的url 就缓存该页面，不然履行正常的页面转向
        if (flag) {
            String query = request.getQueryString();//初始化要缓存的
            if (query != null){
                query = "?" + query;
                log.info("请求被存放缓存：" + url + query);
            }else{
                log.info("请求被存放缓存：" + url);
            }
            super.doFilter(request,response, chain);
        } else {
            chain.doFilter(request, response);
        }
    }

    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紧缩
     */
    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;
    }
}

web.xml配置：

<filter>
    <filter-name>PageEhCacheFilter</filter-name>
    <filter-class>net.sf.ehcache.constructs.web.filter.PageEhCacheFilter</filter-class>
    <init-param>
        <param-name>patterns</param-name>
        
        <param-value>/index.jsp,/index_top.jsp,/index_foot.jsp</param-value>
    </init-param>
</filter>
<filter-mapping>
    <filter-name>PageEhCacheFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

ehcache.xml 配置：