jsp、css、js等静态文件清缓存

小鱼儿 2022-09-03 05:12 247阅读 0赞

ssm项目维护中遇到缓存严重，修改后无法及时加载，需要强制刷新浏览器来清除缓存，因此写了个过滤器来处理。

*  jsp清除缓存
 *  js、css添加时间戳

import org.apache.commons.lang3.StringUtils;
    
    import javax.servlet.*;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import java.io.IOException;
    import java.util.Date;
    
    /** * @className: CleanFrontCacheFilter * @description: * @author: chenlf */
    public class CleanFrontCacheFilter implements Filter { 
        /** 静态资源 为防止缓存，加上时间戳标志 */
        public static final String STATIC_TAIL = "__eval_t=";
    
        @Override
        public void init(FilterConfig filterConfig) throws ServletException { 
        }
    
        @Override
        public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { 
            HttpServletRequest req = (HttpServletRequest)request;
            HttpServletResponse res = (HttpServletResponse)response;
    
            String requestURL = req.getRequestURL().toString();
            String queryStr = req.getQueryString();
    
            //.jsp 清除缓存
            if(requestURL != null && (requestURL.endsWith(".jsp"))){ 
                res.setHeader("Expires", "-1");
                res.setHeader("Cache-Control", "no-cache");
                res.setHeader("Param", "no-cache");
            }
    
            // .js、.css 添加时间戳
            if(requestURL != null && (requestURL.endsWith(".js") || requestURL.endsWith(".css"))) {   // static resource
                String newURL = null;
                if (StringUtils.isNotBlank(queryStr) && queryStr.trim().indexOf(STATIC_TAIL) == -1) { 
                    newURL = requestURL + "?" + queryStr + "&" + STATIC_TAIL + new Date().getTime();
                    res.sendRedirect(newURL);
                    return;
                }
                if (StringUtils.isBlank(queryStr)) { 
                    newURL = requestURL + "?" + STATIC_TAIL + new Date().getTime();
                    res.sendRedirect(newURL);
                    return;
                }
    
                try { 
                    chain.doFilter(request, response);
                } catch (Exception e) { 
                    e.printStackTrace();
                }
            }
        }
    
        @Override
        public void destroy() { 
        }
    }

web.xml

<filter>
    		<filter-name>cleanFrontCacheFilter</filter-name>
    		<filter-class>com.verification.global.filter.CleanFrontCacheFilter</filter-class>
    	</filter>
    	<filter-mapping>
    		<filter-name>cleanFrontCacheFilter</filter-name>
    		<url-pattern>*.jsp</url-pattern>
    		<url-pattern>*.js</url-pattern>
    		<url-pattern>*.css</url-pattern>
    	</filter-mapping>
    	<filter-mapping>
    		<filter-name>cleanFrontCacheFilter</filter-name>
    		<url-pattern>/servlet/*</url-pattern>
    	</filter-mapping>