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JSP过滤器Filter配置过滤类型全部汇总

程序员文章站 2023-01-03 23:31:11
一、配置方法 1 映射过滤应用程序中所有资源 loggerfilter

一、配置方法

1 映射过滤应用程序中所有资源

<filter>
  <filter-name>loggerfilter</filter-name>
  <filter-class>myfilter.loggerfilter</filter-class>
</filter>
<filter-mapping>
  <filter-name>loggerfilter</filter-name>
  <url-pattern>/*</url-pattern> //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1 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>
  <filter-name>loggerfilter</filter-name>
  <url-pattern>*.jsp</url-pattern>//访问当前主机,当前应用程序根目录以所有及子目录下的所有jsp文件
</filter-mapping>

方法2 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

<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“/”

二、实例

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>
<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>

自定义的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;
  }

}

以上这篇jsp过滤器filter配置过滤类型全部汇总就是小编分享给大家的全部内容了,希望能给大家一个参考,也希望大家多多支持。