错误：
输入例外报告
messageInternal Server Error
description服务器遇到内部错误，导致无法完成此请求。
例外
org.apache.jasper.JasperException：java.lang.NullPointerException 根本原因
显示java.lang.NullPointerException note备注GlassFish Server Open Source Edition 4.1日志中提供了异常的完整堆栈跟踪及其根本原因。
EmailConfirmation.jsp
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Dentistree</title>
<link rel="stylesheet" type="text/css" href="EmailConfirmation.css">
</head>
<body>
<button id="home" onmouseover="h1()" onmouseout="h2()"><b>HOME</b></button>
<button id="register" onmouseover="r1()" onmouseout="r2()"><b>REGISTER</b></button>
<button id="login" onmouseover="l1()" onmouseout="l2()"><b>LOGIN</b></button>
<button id="appointment" onmouseover="a1()" onmouseout="a2()"><b>APPOINTMENT</b></button>
<button id="map" onmouseover="m1()" onmouseout="m2()"><b>MAP</b></button>
<button id="report" onmouseover="re1()" onmouseout="re2()"><b>REPORT</b></button>
<button id="doctor" onmouseover="d1()" onmouseout="d2()"><b>DOCTOR</b></button>
<%@page import="javax.mail.PasswordAuthentication"%>
<%@page import="java.util.Properties"%>
<%@page import="javax.mail.Message"%>
<%@page import="javax.mail.MessagingException"%>
<%@page import="javax.mail.Session"%>
<%@page import="javax.mail.Transport"%>
<%@page import="javax.mail.internet.InternetAddress"%>
<%@page import="javax.mail.internet.MimeMessage"%>
<%
String name = request.getParameter("nmtxt");
String pwd = request.getParameter("passtxt");
String date = request.getParameter("txtdate");
String address = request.getParameter("txtadd");
String blood = request.getParameter("bloodgrp");
String sex= request.getParameter("sex");
String email=request.getParameter("emailaddtxt");
final String username="a@.com";
final String password="an";
StringBuffer sb=new StringBuffer();
for(int i=0;i<5;i++)
{
sb.append((char)(int)(Math.random()*79+23+7));
}
String cap=new String(sb);
Properties props=new Properties();
props.put("mail.smtp.ssl.trust", "smtp.gmail.com");
props.put("mail.smtp.auth", true);
props.put("mail.smtp.starttls.enable", true);
props.put("mail.smtp.host", "smtp.gmail.com");
props.put("mail.smtp.port", "587");
String emailtxt1=request.getParameter("emailaddtxt");
Session ses=Session.getInstance(props,new javax.mail.Authenticator()
{
protected PasswordAuthentication getPasswordAuthentication()
{
return new PasswordAuthentication(username, password);
}
});
try
{
Message message=new MimeMessage(ses);
message.setFrom(new InternetAddress("a@.com"));
message.setRecipients(Message.RecipientType.TO,InternetAddress.parse(emailtxt1));
message.setContent("<body>"+"Hi "+name+".<br>"+"You have signed to dentistree through email id:<b>"+emailtxt1+"</b><br>Your password is:<b>"+pwd+"</b>Thanks for registering to dentistree.Your unique identification number is<b></br>"+cap+"</b></body>","text/html");
Transport.send(message);
}
catch(MessagingException e)
{
throw new RuntimeException(e);
}
%>
<%@ page import ="java.sql.*" %>
<%
Class.forName("com.mysql.jdbc.Driver");
Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/dentistree","root", "tiger");
Statement st = con.createStatement();
//ResultSet rs;
String s="insert into patient(name,password, birthdate, address, gender,email,unique_key,bloodgroup) values ("+"'"+name+"','"+ pwd+ "','" + date + "','" + address + "','" + sex + "','" + email +"','" + cap + "','" + blood+"')";
try
{
int i = st.executeUpdate(s);
}
catch(Exception e)
{
out.print(e);
}
session.setAttribute("mail", email);
%>
<div id="maindiv">
<h1 id="title"><b>DentisTree</b></h1>
<h3 id="congo" align="center"><b>CONGRATULATIONS!!!</b></h3>
<form name="mailconfo" action="confirm.jsp">
<pre id="para"> You've successfully created Dentistree account. You're account activation is just a step away.
An email has been sent to your email address.It consist of a unique Dentistree key.Enter the key
in the textfield below to activate your account</pre>
<label id='uniquekey'><b>Enter the unique key:</b></label>
<input type='text' id='uniquekeytxt' name="uniquekeytxt" required>
<input type="submit" value="Submit" id="sub">
<form name="mailconfo" action="confirm.jsp">
</div>
</body>
Confirm.jsp
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Dentistree</title>
<link rel="stylesheet" type="text/css" href="confirm.css">
</head>
<body>
<button id="home" onmouseover="h1()" onmouseout="h2()"><b>HOME</b></button>
<button id="register" onmouseover="r1()" onmouseout="r2()"><b>REGISTER</b> </button>
<button id="login" onmouseover="l1()" onmouseout="l2()"><b>LOGIN</b></button>
<button id="appointment" onmouseover="a1()" onmouseout="a2()"><b>APPOINTMENT</b></button>
<button id="map" onmouseover="m1()" onmouseout="m2()"><b>MAP</b></button>
<button id="report" onmouseover="re1()" onmouseout="re2()"><b>REPORT</b></button>
<button id="doctor" onmouseover="d1()" onmouseout="d2()"><b>DOCTOR</b></button>
<div id="maindiv">
<h1 id="title"><b>DentisTree</b></h1>
<%@ page import ="java.sql.*" %>
<form name="mailconfo">
<%
String conf=request.getParameter("uniquekeytxt");
String mail=session.getAttribute("mail").toString();
Class.forName("com.mysql.jdbc.Driver");
Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/dentistree",
"root", "tiger");
Statement st = con.createStatement();
ResultSet rs = st.executeQuery("select unique_key from patient where email='"+mail+"'");
String s="Update patient set verified='yes' where email='"+mail+"'";
try{
if(conf.equals(rs))
{
try
{
int i = st.executeUpdate(s);
}
catch(Exception e)
{
out.print(e);
}
out.print("<h3 align='center'><b>CONGRATULATIONS!!!</b></h1>");
out.print("<p>Your account has been verified</p>");
out.print("<p>Click on the login to login to your account</p>");
}
else
{
response.sendRedirect("EmailConfirmation.jsp");
}}
catch(Exception e)
{
out.print(e);
}
%>
</form>
</div>
</body>
</html>
confirm.jsp中发生错误。我检查了邮件和uniquekeytxt都有数据。
答案 0 :(得分：0)
在try catch块中包含此代码，然后您就可以了解一下。
try
{
String mail=session.getAttribute("mail").toString();
}
catch(NullPointerException e){}