各位大侠帮帮忙啊

这个问题我搞了很久了 还是不行。真是恼火啊。
在Eclipse中新建了一个tomcat project  命名为lijun在WEB-IF/SRC 下建有测试文件HelloWord.java，
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class HelloWord extends HttpServlet
{
    public void doGet(HttpServletRequest req,HttpServletResponse res)throws ServletException,IOException
    {
res.setContentType("text/html");
PrintWriter out=res.getWriter();
out.println("<html><head><title>helloword</title></head><body>");
out.println("helloword");
out.println("</body></html>");
out.close();

    }
}
在WEB-INF下建有 web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="2.4" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee   http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
  <servlet>
    <servlet-name>HelloWord</servlet-name>
    <servlet-class>HelloWord</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>HelloWord</servlet-name>
    <url-pattern>/HelloWord</url-pattern>
  </servlet-mapping>
</web-app>但在http://localhost:8090/lijun/HelloWord中却访问不了  说找不到所要求的资源，还请大家帮忙解决啊