【java web】过滤器filter

<!-- 编码处理过滤器 -->

   <filter>

      <filter-name>encodingFilter</filter-name>

      <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>

      <init-param>

         <param-name>encoding</param-name>

         <param-value>utf-8</param-value>

      </init-param>

      <init-param>

         <param-name>forceEncoding</param-name>

         <param-value>true</param-value>

      </init-param>

    </filter>   

    <filter-mapping>

       <filter-name>encodingFilter</filter-name>

       <url-pattern>*.do</url-pattern>

    </filter-mapping>

@Override

   protected void doFilterInternal(

         HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)

         throws ServletException, IOException {

 

      if (this.encoding != null && (this.forceEncoding || request.getCharacterEncoding() == null)) {

         request.setCharacterEncoding(this.encoding);

         if (this.forceEncoding) {

            response.setCharacterEncoding(this.encoding);

         }

      }

      filterChain.doFilter(request, response);

   }

package com.my.dm.filter;

import java.io.IOException;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.springframework.web.filter.OncePerRequestFilter;

public class TestFilter extends OncePerRequestFilter{
    
    private Logger logger =LogManager.getLogger(TestFilter.class);
    private String demo;   
    
    

    /**
     * @return the demo
     */
    public String getDemo() {
        return demo;
    }

    /**
     * @param demo the demo to set
     */
    public void setDemo(String demo) {
        this.demo = demo;
    }

    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
            throws ServletException, IOException {
        // TODO Auto-generated method stub
        // 请求的uri
        
        String url = request.getRequestURI();
        
        String hoString = request.getRemoteHost();
        
        String ip  = getIPAddress(request);
        logger.info("url : " + url);
        logger.info("ip : " + ip);    
        
        logger.info("demo : " + demo);    
        
        // 将请求转发到目的地 
        filterChain.doFilter(request, response);        
    }
      
     public void destroy() {
       
     }
     
     public void init(){
         
     }
    
    
    //获取真实ip
    public static String getIPAddress(HttpServletRequest request) {
        String ip = null;

        //X-Forwarded-For：Squid 服务代理
        String ipAddresses = request.getHeader("X-Forwarded-For");
    if (ipAddresses == null || ipAddresses.length() == 0 || "unknown".equalsIgnoreCase(ipAddresses)) {
            //Proxy-Client-IP：apache 服务代理
            ipAddresses = request.getHeader("Proxy-Client-IP");
        }
    if (ipAddresses == null || ipAddresses.length() == 0 || "unknown".equalsIgnoreCase(ipAddresses)) {
            //WL-Proxy-Client-IP：weblogic 服务代理
            ipAddresses = request.getHeader("WL-Proxy-Client-IP");
        }
    if (ipAddresses == null || ipAddresses.length() == 0 || "unknown".equalsIgnoreCase(ipAddresses)) {
            //HTTP_CLIENT_IP：有些代理服务器
            ipAddresses = request.getHeader("HTTP_CLIENT_IP");
        }
    if (ipAddresses == null || ipAddresses.length() == 0 || "unknown".equalsIgnoreCase(ipAddresses)) {
            //X-Real-IP：nginx服务代理
            ipAddresses = request.getHeader("X-Real-IP");
        }

        //有些网络通过多层代理，那么获取到的ip就会有多个，一般都是通过逗号（,）分割开来，并且第一个ip为客户端的真实IP
        if (ipAddresses != null && ipAddresses.length() != 0) {
            ip = ipAddresses.split(",")[0];
        }

        //还是不能获取到，最后再通过request.getRemoteAddr();获取
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ipAddresses)) {
            ip = request.getRemoteAddr();
        }
        return ip.equals("0:0:0:0:0:0:0:1")?"127.0.0.1":ip;
    }

}

<!-- 获取登陆者信息 -->
    <filter>
        <filter-name>testFilter</filter-name>
        <filter-class>com.my.dm.filter.TestFilter</filter-class>
    
        <init-param>
            <param-name>demo</param-name>
            <param-value>112.2.36</param-value>
        </init-param>
        </filter>
    <filter-mapping>
        <filter-name>testFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>