Jsp过滤器Filter配置过滤类型汇总 filter 过滤器 不过滤

<filter>
<filter-name>loggerfilter</filter-name>
<filter-class>myfilter.LoggerFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>loggerfilter</filter-name>
<url-pattern>/*</url-pattern>//访问当前主机，当前应用程序根下的所有文件包括多级子目录下的所有文件，注意这里*前有“/”
</filter-mapping>

2.过滤指定的类型文件资源

<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>//访问当前主机，当前应用程序根目录下的所有html文件，注意：*.html前没有“/”,否则错误

</filter-mapping>

其中*.html要过滤jsp那么就改*.html为*.jsp,但是注意没有“/”斜杠

如果要同时过滤多种类型资源：

方法一：url-pattern分开写

<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>

方法二、将url-pattern 合并

<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两类型之间用分号“；”间隔

3.过滤指定的目录下的所有文件

<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>//访问当前主机，当前应用程序根目录下的folder_name子目录（可以是多级子目录）下所有文件

</filter-mapping>

4.过滤指定的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.过滤指定文件（即单一文件）

<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、过滤指定目录下的指定类型的所有文件

这种情况下，在web.xml中无法一次性配置完成，需要结合filter的实现类

首先，在web.xml中配置过滤指定目录下的所有文件（如上3）

<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>

然后，在filter的实现类中的doFilter方法中获取请求的uri或者url，判断uri或者url中是否包含指定文件类型的字符串，决定是否过滤

//获得用户请求的uri
String uri =request.getRequestURI();

if(uri.contains(".jsp")||uri.contains(".html"))
{
System.out.println("开始过滤"+url);
}

7、过滤指定目录下指定类型的单一文件

<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杠“/”
###############使用filter缓存js、css、图片等文件###############

在web.xml中配置如下信息

<!--不缓存文件 -->

<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>

<!--缓存文件一周 -->

<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>

自定义的filter如下：

public classResponseHeaderFilter implementsFilter {
FilterConfigfc;

public voiddoFilter(ServletRequest req, ServletResponse res,
FilterChain chain) throws IOException, ServletException {
HttpServletResponse response = (HttpServletResponse) res;
// set the provided HTTP response parameters
for (Enumeration e = fc.getInitParameterNames();e.hasMoreElements();) {
String headerName = (String) e.nextElement();
response.addHeader(headerName,fc.getInitParameter(headerName));
}
// pass the request/response on
chain.doFilter(req, response);
}

public voidinit(FilterConfig filterConfig) {
this.fc = filterConfig;
}

public voiddestroy() {
this.fc = null;
}

}

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