Servlet跳转进入JSP页面什么都不显示？

servlet代码：public class TestServlet extends HttpServlet {

private static final long serialVersionUID = 5222793251610509039L; public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
request.setCharacterEncoding("UTF-8");

} public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request,response);
}

}JSP代码：
<%@ page language="java" import="java.util.*" contentType="text/html;charset=UTF-8" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">    
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<script>
window.onload=function(){
alert("");
}
</script>
  </head>
  <body>
用户名：<input type="text" id="username" onblur=""/><label id="msg"></label>
  </body>
</html>加入小脚本就可以显示，但加入js和html代码都无法显示，怎么会这样呢？