JAVA过滤器

安全过滤器

package com.filter;import java.io.IOException;import javax.servlet.http.*;import javax.servlet.*;public class AnQuanFilter implements Filter{public void destroy() {}public void doFilter(ServletRequest request, ServletResponse response,FilterChain chain) throws IOException, ServletException {HttpServletRequest req=(HttpServletRequest)request;HttpServletResponse res=(HttpServletResponse)response;String str=(String)req.getSession().getAttribute("name");if(str!=null && !str.equals("")){chain.doFilter(request, response);System.out.println("00000000000000000");}else{System.out.println("00000000111111111");res.sendRedirect(application.getContextPath()+"/index.jsp");}}ServletContext application=null;public void init(FilterConfig filterConfig) throws ServletException {application=filterConfig.getServletContext();System.out.println("----------------");}}

字符过滤器

package com.filter;import java.io.IOException;import java.io.UnsupportedEncodingException;import javax.servlet.Filter;import javax.servlet.FilterChain;import javax.servlet.FilterConfig;import javax.servlet.ServletException;import javax.servlet.ServletRequest;import javax.servlet.ServletResponse;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletRequestWrapper;import javax.servlet.http.HttpServletResponse;public class EncodingFilter implements Filter{public void destroy() {}public void doFilter(ServletRequest arg0, ServletResponse arg1,FilterChain arg2) throws IOException, ServletException {HttpServletRequest request=(HttpServletRequest)arg0;HttpServletResponse response=(HttpServletResponse)arg1;request.setCharacterEncoding("utf-8");MyRequest mrequest=new MyRequest(request);arg2.doFilter(mrequest, response);}public void init(FilterConfig arg0) throws ServletException {}}class MyRequest extends HttpServletRequestWrapper{private HttpServletRequest request;public MyRequest(HttpServletRequest request) {super(request);this.request=request;}public String getParameter(String name){String str=request.getParameter(name);if(str==null || str.equals("")){str="";}if(request.getMethod().equalsIgnoreCase("get")){try {str=new String(str.getBytes("ISO-8859-1"),"utf-8");if(str.contains("中国")){str=str.replace("中国", "***");}} catch (UnsupportedEncodingException e) {e.printStackTrace();}}return str;}}

日志过滤器

package com.filter;import java.io.IOException;import javax.servlet.*;import javax.servlet.http.*;public class LogFilter implements Filter{public void destroy() {}public void doFilter(ServletRequest request, ServletResponse response,FilterChain chain) throws IOException, ServletException {application.log(request.getRemoteAddr()+"====="+new java.util.Date().toLocaleString());chain.doFilter(request, response);}ServletContext application=null;public void init(FilterConfig filterConfig) throws ServletException { application=filterConfig.getServletContext();}}

web.xml

<?xml version="1.0" encoding="UTF-8"?><web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">  <welcome-file-list>    <welcome-file>index.jsp</welcome-file>  </welcome-file-list>    <servlet>  <servlet-name>Login</servlet-name>    <servlet-class>com.servlet.Login</servlet-class>  </servlet>  <servlet>    <description>This is the description of my J2EE component</description>    <display-name>This is the display name of my J2EE component</display-name>    <servlet-name>Code</servlet-name>    <servlet-class>com.util.Code</servlet-class>  </servlet>  <filter>  <filter-name>AnQuan</filter-name>  <filter-class>com.filter.AnQuanFilter</filter-class>  </filter>  <filter-mapping>  <filter-name>AnQuan</filter-name>  <url-pattern>/success.jsp</url-pattern>  </filter-mapping>      <filter>  <filter-name>EncodingFilter</filter-name>  <filter-class>com.filter.EncodingFilter</filter-class>  </filter>  <filter-mapping>  <filter-name>EncodingFilter</filter-name>  <url-pattern>/*</url-pattern>  </filter-mapping>      <servlet-mapping>  <servlet-name>Login</servlet-name>  <url-pattern>/Login</url-pattern>  </servlet-mapping>  <servlet-mapping>    <servlet-name>Code</servlet-name>    <url-pattern>/Code</url-pattern>  </servlet-mapping>    <listener>  <listener-class>com.listener.SessionListener</listener-class>  </listener>  </web-app>