servlet/jsp运行出错，请高手帮帮忙

调试中都没出现错误，但运行却出现一个保存文件的对话框，而没出现客户端和服务器端的IP地址及端口号等，请高手指点一下
servlet代码如下
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Enumeration;import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;public class OutputInfoServlet extends HttpServlet
{
  public void doGet(HttpServletRequest req,HttpServletResponse resp)throws ServletException,IOException
  {
     resp.setContentType("text/html,charset=gb2312");//此行必须放在15行之前才能设置响应的字符编码
     PrintWriter out=resp.getWriter();
     Enumeration headNames=req.getHeaderNames();
     out.println("<html><head>");
     out.println("<title>Info page</title>");
     out.println("</head>");
     out.println("<body><center>");
     out.println("<table border=1 align=center>");
     out.println("caption>Servlet接受到的HTTp消息报头的信息</caption>");
     out.println("<tr bgcolor=#999999>");
     out.println("<th>消息报头的名字</th>");
     out.println("<th>消息报头的值</th>");
     out.println("</tr>");
     
     while(headNames.hasMoreElements())
     {
        String name=(String)headNames.nextElement();
        String value=req.getHeader(name);
        out.println("<tr>");
        out.println("<td>"+name+"</td>");
        out.println("<td>"+value+"</td>");
        out.println("</tr>");
     }  
     out.println("</table><p>");
     out.println("<table border=1 align=center>");
     out.println("<caption>其他访问信息</caption>");
     out.println("<tr>");
     out.println("<td>客户端的IP地址</td>");
     out.println("<td>"+req.getRemoteAddr()+"</td>");
     out.println("</tr>");
     
     out.println("<tr>");
     out.println("<td>客户端的端口号</td>");
     out.println("<td>"+req.getRemotePort()+"</td>");
     out.println("</tr>");
     
     out.println("<tr>");
     out.println("<td>服务器端的IP地址</td>");
     out.println("<td>"+req.getLocalAddr()+"</td>");
     out.println("</tr>");
     
     out.println("<tr>");
     out.println("<td>服务器端的端口号</td>");
     out.println("<td>"+req.getLocalPort()+"</td>");
     out.println("</tr>");
     
     out.println("</table>");
     
     out.println("</center></body></html>");
     out.close();
  }
}
web.xml配置如下
<?xml version="1.0" encoding="ISO-8859-1"?><web-app 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"
   version="2.5"> 
    <servlet>
        <servlet-name>HelloWorld</servlet-name>
        <servlet-class>HelloWorldServlet</servlet-class>
    </servlet>    <servlet-mapping>
        <servlet-name>HelloWorld</servlet-name>
        <url-pattern>/Hello</url-pattern>
    </servlet-mapping>
    <servlet>
        <servlet-name>WelcomeServlet</servlet-name>
        <servlet-class>WelcomeServlet</servlet-class>
        <init-param>
         <param-name>greeting</param-name>
         <param-value>welcome you</param-value>
      </init-param>
    </servlet>    <servlet-mapping>
        <servlet-name>WelcomeServlet</servlet-name>
        <url-pattern>/Welcome</url-pattern>
    </servlet-mapping>
    <servlet>
        <servlet-name>OutputInfoServlet</servlet-name>
        <servlet-class>OutputInfoServlet</servlet-class>
    </servlet>    <servlet-mapping>
        <servlet-name>OutputInfoServlet</servlet-name>
        <url-pattern>/output</url-pattern>
    </servlet-mapping>  
</web-app>