JSP+Servlet实现注册登录功能
JSP是表现层，显示出要注册的内容。用表单提交进行数据转发，表单提交给Servlet进行处理，进行数据库连接
将数据写入数据库，写入成功，返回成功注册信息。具体代码如下:
JSP代码负责显示，充当显示层。与用户进行交互，将用户提交数据转发给服务器处理的功能。
<%@ page language="java" contentType="text/html" pageEncoding="GBK"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>用户注册</title>
<style type="text/css">
body{
margin: 0px;font-size: 12px;
}
.box{
border: 1px solid #D1DEB2; width: 150px; height: 20px;
}
.div1{
background-image: url(images/bg.jpg);
height: 600px;
width: 803px;
padding-left:20px;
padding-top:220px;
text-align:left;
}
</style>
<script type="text/javascript">
function reg(form){
if(form.username.value == ""){
alert("用户不能为空！");
return false;
}
if(form.password.value == ""){
alert("密码不能为空！");
return false;
}
if(form.repassword.value == ""){
alert("确认密码不能为空！");
return false;
}
if(form.password.value != form.repassword.value){
alert("两次密码输入不一致！");
return false;
}
if(form.question.value == ""){
alert("密码找回问题不能为空！");
return false;
}
if(form.answer.value == ""){
alert("密码找回答案不能为空！");
return false;
}
if(form.email.value == ""){
alert("电子邮箱不能为空！");
return false;
}
}
</script>
</head>
<body>
<div align="center">
<div class="div1">
<form action="RegServlet" method="post" onsubmit="return reg(this);">
<table align="center" border="0" width="500">
<tr>
<td align="right" width="30%">用户名：</td>
<td><input type="text" name="username" class="box"></td>
</tr>
<tr>
<td align="right">密 码：</td>
<td><input type="password" name="password" class="box"></td>
</tr>
<tr>
<td align="right">确认密码：</td>
<td><input type="password" name="repassword" class="box"></td>
</tr>
<tr>
<td align="right">性 别：</td>
<td>
<input type="radio" name="sex" value="男" checked="checked">男
<input type="radio" name="sex" value="女">女
</td>
</tr>
<tr>
<td align="right">密码找回问题：</td>
<td><input type="text" name="question" class="box"></td>
</tr>
<tr>
<td align="right">密码找回答案：</td>
<td><input type="text" name="answer" class="box"></td>
</tr>
<tr>
<td align="right">邮 箱：</td>
<td><input type="text" name="email" class="box"></td>
</tr>
<tr>
<td colspan="2" align="center" height="40">
<input type="submit" value="注 册">
<input type="reset" value="重 置">
</td>
</tr>
</table>
</form>
</div>
</div>
</body>
</html>
Servlet负责处理业务逻辑，将提交的数据进行处理同。例如，进行数据验证，身份验证等等。具体业务处理代码如下:
package com.lyq;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class RegServlet extends HttpServlet {
private static final long serialVersionUID = 1789481329876401944L;
// 数据库连接Connection
private Connection conn;
// 初始化方法
public void init() throws ServletException {
super.init();
try {
// 加载驱动
Class.forName("com.mysql.jdbc.Driver");
// 数据库连接url
String url = "jdbc:mysql://localhost:3306/registersystem";
// 获取数据库连接
conn = DriverManager.getConnection(url, "root", "123");
System.out.println("数据库连接成功!");
} catch (Exception e) {
e.printStackTrace();
}
}
// doPost()方法处理注册请求
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// 设置request与response的编码
response.setContentType("text/html");
request.setCharacterEncoding("GBK");
response.setCharacterEncoding("GBK");
// 获取表单中属性值
String username = request.getParameter("username");
String password = request.getParameter("password");
String sex = request.getParameter("sex");
String question = request.getParameter("question");
String answer = request.getParameter("answer");
String email = request.getParameter("email");
// 判断数据库中否连接成功
if (conn != null) {
try {
// 插入注册信息的SQL语句(使用?占位符)
String sql = "insert into tb_user(username,sex,question,answer,email,password) "
+ "values(?,?,?,?,?,?)";
// 创建PreparedStatement对象
PreparedStatement ps = conn.prepareStatement(sql);
// 对SQL语句中的参数动态赋值
ps.setString(1, username);
ps.setString(2, password);
ps.setString(3, sex);
ps.setString(4, question);
ps.setString(5, answer);
ps.setString(6, email);
// 执行更新操作
ps.executeUpdate();
// 获取PrintWriter对象
PrintWriter out = response.getWriter();
// 输出注册结果信息
out.print("<h1 aling='center'>");
out.print(username + "注册成功！");
out.print("</h1>");
out.flush();
out.close();
} catch (Exception e) {
e.printStackTrace();
}
} else {
// 发送数据库连接错误提示信息
response.sendError(500, "数据库连接错误！");
}
}
}
虽然这个业务比较简单，重要的是思想。将表现层与业务处理层进行分离处理，MVC思想的具体表现。将在以后的项目中 更加重要。