课程引言动手动脑
网站系统开发需要掌握的技术
技术内容
HTML语法、CSS语法、JavaScript语法
图像处理
Flash动画创意、GIF动画制作、网页图片处理
后台编程
*数据库:SQLServer设计、MySQL设计、Access设计
*编程语言:ASP、JSP、VBScript、JavaScript、PHP、ASP.net
*编程实例:文章发布系统、留言板、BBS、会员注册系统、在线购物网站
课堂作业:绘制一个登陆界面实现数据库连接。
输入正确的用户密码:
错误的:
不输入:
package com.jaovo.msg.Util; import java.sql.*; public class DBUtil { public static Connection getConnection() { try { //1 加载驱动 Class.forName("com.mysql.jdbc.Driver").newInstance(); } catch (InstantiationException | IllegalAccessException | ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } String user = "root"; String password = "root"; String url = "jdbc:mysql://localhost:3306/jaovo_msg"; Connection connection = null; try { //2 创建链接对象connection connection = DriverManager.getConnection(url,user,password); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return connection; } //关闭资源的方法 public static void close(Connection connection ) { try { if (connection != null) { connection.close(); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } public static void close(PreparedStatement preparedStatement ) { try { if (preparedStatement != null) { preparedStatement.close(); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } public static void close(ResultSet resultSet ) { try { if (resultSet != null) { resultSet.close(); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }
<%@ 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> <title>用户登录界面</title> </head> <body> <form action="add.jsp" method="get"> <%=request.getAttribute("a") %> <table align="center" border="1" width="500"> <tr> <td>用户名:</td> <td> <input type="text" name="username"/> </td> </tr> <tr> <td>输入密码:</td> <td> <input type="password" name="password"/> </td> </tr> <tr align="center"> <td colspan="2"> <input type="submit" value="提交" /> <input type="reset" value="重置" /> </td> </tr> </table> </form>> </body> </html>
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ page import = "com.jaovo.msg.Util.DBUtil" %> <%@ page import = "java.sql.*" %> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <% //接受客户端传递过来的参数 String username = request.getParameter("username"); if(username==null||"".equals(username)) { request.setAttribute("a", "请输入用户名!"); %> <jsp:forward page="addInput.jsp"></jsp:forward> <% } String password = request.getParameter("password"); String sql="select * from t_user1 where username=?"; Connection connection=DBUtil.getConnection(); PreparedStatement preparedStatement=connection.prepareStatement(sql); preparedStatement.setString(1, username); ResultSet resultset=preparedStatement.executeQuery(); boolean flag=false; while(resultset.next()) { flag=true; if(resultset.getString("password").equals(password)) { request.setAttribute("a", "登陆成功!"); %> <%=request.getAttribute("a")%> <% } else { request.setAttribute("a", "登录失败!"); %> <jsp:forward page="addInput.jsp"></jsp:forward> <% } } if(!flag) { request.setAttribute("a","用户不存在!"); %> <jsp:forward page="addInput.jsp"></jsp:forward> <% } %> <body> </body> </html>
我计划每天花费一小时在这个课程上。