一、配置方法
1 映射過濾應用程序中所有資源
<filter> <filter-name>loggerfilter</filter-name> <filter-class>myfilter.LoggerFilter</filter-class> </filter> <filter-mapping> <filter-name>loggerfilter</filter-name> <url-pattern>/*</url-pattern> //訪問當前主機，當前應用程序根下的所有文件包括多級子目錄下的所有文件，注意這裡*前有“/” </filter-mapping>
2 過濾指定的類型文件資源
<filter> <filter-name>loggerfilter</filter-name> <filter-class>myfilter.LoggerFilter</filter-class> </filter> <filter-mapping> <filter-name>loggerfilter</filter-name> <url-pattern>*.html</url-pattern> //訪問當前主機，當前應用程序根目錄下的所有html文件，注意：*.html前沒有“/”,否則錯誤 </filter-mapping>
其中*.html要過濾jsp那麼就改*.html為*.jsp，但是注意沒有“/”斜槓。如果要同時過濾多種類型資源：
方法1 url-pattern 分開寫
<filter> <filter-name>loggerfilter</filter-name> <filter-class>myfilter.LoggerFilter</filter-class> </filter> <filter-mapping> <filter-name>loggerfilter</filter-name> <url-pattern>*.html</url-pattern> </filter-mapping> <filter-mapping> <filter-name>loggerfilter</filter-name> <url-pattern>*.jsp</url-pattern>//訪問當前主機，當前應用程序根目錄以所有及子目錄下的所有jsp文件 </filter-mapping>
方法2 將url-pattern合並
<filter> <filter-name>loggerfilter</filter-name> <filter-class>myfilter.LoggerFilter</filter-class> </filter> <filter-mapping> <filter-name>loggerfilter</filter-name> <url-pattern>*.html;*.jsp</url-pattern> </filter-mapping>//*.html;*.jsp兩類型之間用分號;間隔
3 過濾指定的目錄下的所有文件
<filter> <filter-name>loggerfilter</filter-name> <filter-class>myfilter.LoggerFilter</filter-class> </filter> <filter-mapping> <filter-name>loggerfilter</filter-name> <url-pattern>/folder_name/*</url-pattern>//訪問當前主機，當前應用程序根目錄下的folder_name子目錄（可是多級子目錄）下所有文件 </filter-mapping>
4 過濾指定的servlet
<filter> <filter-name>loggerfilter</filter-name> <filter-class>myfilter.LoggerFilter</filter-class> </filter> <filter-mapping> <filter-name>loggerfilter</filter-name> <servlet-name>loggerservlet</servlet-name> </filter-mapping> <servlet> <servlet-name>loggerservlet</servlet-name> <servlet-class>myfilter.LoggerServlet</servlet-class> </servlet>
5 過濾指定文件（即單一文件）
<filter> <filter-name>loggerfilter</filter-name> <filter-class>myfilter.LoggerFilter</filter-class> </filter> <filter-mapping> <filter-name>loggerfilter</filter-name> <url-pattern>/simplefilter.html</url-pattern> </filter-mapping>
6 過濾指定目錄下的指定類型的所有文件
這種情況下在web.xml中無法一次性配置完成，需要結合filter的實現類
首先在web.xml中配置過濾指定目錄下的所有文件
<filter> <filter-name>loggerfilter</filter-name> <filter-class>myfilter.LoggerFilter</filter-class> </filter> <filter-mapping> <filter-name>loggerfilter</filter-name> <url-pattern>/dir_name/*</url-pattern> </filter-mapping>
然後在filter的實現類中的doFilter方法中獲取請求的uri或者url，判斷uri或者url中是否包含指定文件類型的字符串，決定是否過濾
//獲得用戶請求的uri
String uri = request.getRequestURI();
if(uri.contains(".jsp")||uri.contains(".html"))
System.out.println("開始過濾"+url);
7 過濾指定目錄下指定類型的單一文件
<filter> <filter-name>loggerfilter</filter-name> <filter-class>myfilter.LoggerFilter</filter-class> </filter> <filter-mapping> <filter-name>loggerfilter</filter-name> <url-pattern>/dir_name/index.jsp</url-pattern> </filter-mapping>
以上都要注意是否有斜槓“/”
二、實例
不緩存文件
<filter>
<filter-name>NoCache</filter-name>
<filter-class>com.sys.common.Filters.ResponseHeaderFilter
</filter-class>
<init-param>
<param-name>Cache-Control</param-name>
<param-value>no-cache, must-revalidate</param-value>
</init-param>
</filter>
緩存文件一周
<filter>
<filter-name>CacheForWeek</filter-name>
<filter-class>com.sys.common.Filters.ResponseHeaderFilter
</filter-class>
<init-param>
<param-name>Cache-Control</param-name>
<param-value>max-age=604800, public</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>CacheForWeek</filter-name>
<url-pattern>/images/*</url-pattern>
</filter-mapping>
<filter-mapping>
<filter-name>CacheForWeek</filter-name>
<url-pattern>*.js</url-pattern>
</filter-mapping>
<filter-mapping>
<filter-name>CacheForWeek</filter-name>
<url-pattern>*.css</url-pattern>
</filter-mapping>
自定義的filter：
public class ResponseHeaderFilter implements Filter {
FilterConfig fc;
public void doFilter(ServletRequest req, ServletResponse res,FilterChain chain) throws IOException, ServletException {
HttpServletResponse response = (HttpServletResponse) res;
for (Enumeration e = fc.getInitParameterNames(); e.hasMoreElements();) {
String headerName = (String) e.nextElement();
response.addHeader(headerName, fc.getInitParameter(headerName));
}
chain.doFilter(req, response);
}
public void init(FilterConfig filterConfig) {
this.fc = filterConfig;
}
public void destroy() {
this.fc = null;
}
}
以上這篇JSP過濾器Filter配置過濾類型全部匯總就是小編分享給大家的全部內容了，希望能給大家一個參考，也希望大家多多支持。
