获取客户端计算机的ip地址的方法

1.过滤器

package cn.com.dzqc.interceptor;
import java.io.IOException;
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.HttpServletResponse;
import javax.servlet.http.HttpSession;
/**
 * 获取客户端计算机的ip地址的方法
 * @author Administrator
 *
 */
public class IpFilter implements Filter {
	/**
	 * 销毁方法
	 */
	public void destroy() {
		// TODO Auto-generated method stub
	}

	/**
	 * 过滤方法
	 */
	public void doFilter(ServletRequest sreq, ServletResponse sresp, FilterChain chain)
			throws IOException, ServletException {
		if (!(sreq instanceof HttpServletRequest) || !(sresp instanceof HttpServletResponse)) {
			throw new ServletException("OncePerRequestFilter just supports HTTP requests");
		}
		HttpServletRequest httpRequest = (HttpServletRequest) sreq;
		HttpSession session = httpRequest.getSession();
		
		if(session.isNew()) {
			System.out.println("第一次进入");
			String ip=getIpAddr(httpRequest);
			System.out.println(ip);
		}
		chain.doFilter(sreq, sresp);
	}
	
	/**
	 * 初始化方法
	 */
	public void init(FilterConfig config) throws ServletException {
		// TODO Auto-generated method stub
	}
	/***
	 * 获取客户端计算机的ip地址
	 * @param request
	 * @return
	 */
	public String getIpAddr(HttpServletRequest request) {
       String ip = request.getHeader("x-forwarded-for");
       if(ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
           ip = request.getHeader("Proxy-Client-IP");
       }
       if(ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
           ip = request.getHeader("WL-Proxy-Client-IP");
       }
       if(ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
           ip = request.getRemoteAddr();
       }
       return ip;
	}
	
}

通过HttpSession 对象的isNew方法判断session是不是新创建的

2.web.xml文件的配置

        <filter>
		<filter-name>WmsFilter</filter-name>
		<filter-class>cn.com.dzqc.interceptor.IpFilter</filter-class>
		<async-supported>true</async-supported>
	</filter>
	<filter-mapping>
		<filter-name>WmsFilter</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>