javaweb实现简单的登录注册
昨天用java写了一个简单的web，实现了登录注册，工具是Eclipse，部署在Tomcat，用了一下jsp+servlet，前台页面用了一下bootstrap，数据库用的MySQL，虽然非常简单，但是还是出现了很多错误，主要问题是在前台向后台传输数据、连接数据库和写sql代码，连接数据库要用mysql-connector-java-5.1.7-bin.jar包。直接看代码吧：
界面：bootstrap的包和jquery-1.7.2要引正确，按ctr键，鼠标点击便可进入说明路径正确
<%@ page language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>网络交友</title>
<link rel="stylesheet" type="text/css" href="./css/bootstrap.css">
<link rel="stylesheet" type="text/css" href="./css/bootstrap-theme.css">
<script type="text/javascript" src="./javascript/jquery-1.7.2.js"></script>
<script type="text/javascript" src="./javascript/bootstrap.js"></script>
<style type="text/css">
input.middle {
vertical-align: middle;
}
label {
vertical-align: middle;
}
</style>
</head>
<body>
<div id="Layer"
style="position: absolute; width: 100%; height: 100%; z-index: -1">
<img src="./images/shiChao.png" height="100%" width="100%" />
</div>
<div
style="width: 82px; height: 67px; background-image: url(./images/backGroundIcon.png); position: absolute; top: 11%; left: 53%"></div>
<div
style="font-size: 30px; position: absolute; top: 20%; left: 65%; color: #ffffff; font-family: 微软雅黑">网络交友</div>
<form method="post" action="form">
<table style="position: absolute; top: 33%; left: 61%">
<tr>
<td>
<div class="input-group">
<span class="input-group-addon"><span
class="glyphicon glyphicon-user"></span></span> <input
style="width: 261px; height: 40px" type="text"
class="form-control" name="username" placeholder="用户名">
</div>
<div style="height: 20px"></div>
</td>
</tr>
<tr>
<td>
<div class="input-group">
<span class="input-group-addon"><span
class="glyphicon glyphicon-lock"></span></span> <input
style="width: 261px; height: 40px" type="password"
class="form-control" name="password" placeholder="密码">
</div>
<div style="height: 15px"></div>
</td>
</tr>
<tr>
<td>
<div>
<div style="float: left; font-size: 15; color: #000000">
<input id="checkbox" type="checkbox"><label
style="font-weight: 400" for="checkbox"> 记住密码</label>
</div>
<div style="text-align: right">
<a href="ZhuCe.jsp" style="font-size: 15; color: #000000">注册</a>
</div>
<div style="height: 15px"></div>
</div>
</td>
</tr>
<tr>
<td>
<div>
<button id="submit"
style="width: 300px; height: 40px; background-color: #3162BB;"
type="submit" class="btn btn-primary btn-lg">登 录</button>
</div>
</td>
</tr>
</table>
</form>
</body>
</html>
在web.xml文件里可以设置启动页面，和页面对应的类servlet
注意:类的地址（包名.类名等）
代码：
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0"> <display-name>System01</display-name> <welcome-file-list> <welcome-file>login.jsp</welcome-file> </welcome-file-list> <servlet> <servlet-name>form</servlet-name> <servlet-class>org.system.login.FormServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>form</servlet-name> <url-pattern>/form</url-pattern> </servlet-mapping> </web-app>
处理数据的后台类FormServlet.class
package org.system.login;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class FormServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public static Connection conn = null;
/**
* 重写service方法 处理前台传过来的数据和处理成功后跳转页面
*/
@Override
protected void service(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
// 设置客户端的格式
request.setCharacterEncoding("utf-8");
// 获取Login.Jsp中控件输入的值
String name = request.getParameter("username");
String pwd = request.getParameter("password");
System.out.println("姓名：" + name);
System.out.println("密码：" + pwd);
// 驱动程序名
String driver = "com.mysql.jdbc.Driver";
// URL指向要访问的数据库名study
String url = "jdbc:mysql://127.0.0.1:3306/study";
String user = "root"; // MySQL配置时的用户名
String password = "123456"; // MySQL配置时的密码
try {
// 加载驱动程序
Class.forName(driver);
// 连接数据库
Connection conn = DriverManager.getConnection(url, user, password);
if (!conn.isClosed())
System.out.println("Succeeded connecting to the Database!");
// statement用来执行sql语句
Statement statement = conn.createStatement();
// 写sql一定要注意
String sql = "select * from user where username = " + "'" + name + "'";
System.out.println(sql);
// sql执行的结果集
ResultSet rs = statement.executeQuery(sql);
if (rs.next()) {
String pwdStr = null;
// 选择pwd这列数据
pwdStr = rs.getString("pwd");
System.out.println(pwdStr);
if (rs.getString("pwd").equals(pwd)) {
// 登录成功跳转的页面
response.sendRedirect("./loginSucess.jsp");
}
} else {
String sqlStr = "insert into user(username,pwd) values('" + name + "','" + pwd + "')";
Statement MyStatement;
try {
MyStatement = conn.createStatement();
MyStatement.executeUpdate(sqlStr);
System.out.println("添加成功");
// 注册成功后跳转的页面
response.sendRedirect("./index.jsp");
} catch (Exception e) {
System.out.println("添加失败");
}
}
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
虽然写的又简单又挫，但是还是有一定收获的，加油!
运行结果: bootstrap框架还是比较漂亮的
