jsp条件判断网页转向有关问题_Java Web开发

jsp条件判断网页转向问题

这是 loginok.jsp 网页
<%@ page language="java" import="java.util.*" pageEncoding="gbk"%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title><%=request.getServerName() %></title>
</head>

<body>
<% request.setCharacterEncoding("GBK");
String username=request.getParameter("name");
String password=request.getParameter("pass");
if(username.equals("小鱼")&&password.equals("123456"))
{%><jsp:forward page="clock.jsp"/>
<%}
/*out.println("欢迎"+username+"成功登陆聊天室系统！");*/
else response.sendRedirect("login");

%>

</body>
</html>

这是 clock.jsp 网页
<%@ page language="java" import="java.util.*" pageEncoding="gbk"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title> <%=request.getServerName() %></title>
</head>

<body>
<%out.println("当前时间是："+new Date());
response.setHeader("Refresh","1");
%>
</body>
</html>

为什么会出现
org.apache.jasper.JasperException: An exception occurred processing JSP page /loginok.jsp at line 12

9: <% request.setCharacterEncoding("GBK");
10: String username=request.getParameter("name");
11: String password=request.getParameter("pass");
12: if(username.equals("小鱼")&&password.equals("123456"))
13: {%><jsp:forward page="clock.jsp"/>
14: <%}
15: /*out.println("欢迎"+username+"成功登陆聊天室系统！");*/

Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:553)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:457)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:391)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)

------解决方案--------------------------------------------------------
jsp页面不能编译，你打印下用户名是不是传入到这个页面了，一定要保证参数传过来了
------解决方案--------------------------------------------------------
你没有对username和password判断是否空

HTML code

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>  <title><%=request.getServerName() %></title>  </head>    <body>  <% request.setCharacterEncoding("GBK");  String username=request.getParameter("name");  String password=request.getParameter("pass");  if( null!=username&&null!=password&&username.equals("小鱼")&&password.equals("123456"))  {%><jsp:forward page="clock.jsp"/>  <%}  /*out.println("欢迎"+username+"成功登陆聊天室系统！");*/  else response.sendRedirect("login");   %>    </body></html>