<%@ page language="java" import="java.util.*" pageEncoding="gb2312"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP 'Login.jsp' starting page</title>
</head>
<body>
<form action="Login.jsp" method="post">
<tr>
<td>用户名 :</td>
<td><input type="text" name ="logname"></td>
</tr>
<tr>
<td>密码 :</td>
<td><input type="password" name ="password"></td>
</tr>
<tr>
<td colspan="2"><input type="submit" value="提交 "></td>
</tr>
</form>
<%
String logname = request.getParameter("logname");
String password= request.getParameter("password");
if(logname.equals("admin")&&password.equals("root"))
{
response.sendRedirect("success.jsp");
}else{
response.sendRedirect("fault.jsp");
}
%>
</body>
</html>
这是我写的简单的JSP登录代码程序,若输入账号为:admin 密码为:root则跳转到success.jsp,若错误,则跳转到fault.jsp页面
下面是报错信息
org.apache.jasper.JasperException: Exception in JSP: /Login.jsp:39
36: <%
37: String logname = request.getParameter("logname");
38: String password= request.getParameter("password");
39: if(logname.equals("admin")&&password.equals("root"))
40:
41: {
42: response.sendRedirect("success.jsp");
Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:451)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:373)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
root cause
java.lang.NullPointerException
org.apache.jsp.Login_jsp._jspService(Login_jsp.java:82)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:331)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)