12.9自习
三小时理解后台应用方式方法
主要学习页面,写了添加用户页面,为每个用户职位设置编号,登录时输入用户密码,后台确认用户职位打开相应页面
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>登录添加</title> <style> .a{ margin-top: 20px; } .b{ font-size: 20px; width: 160px; color: white; background-color: greenyellow; } </style> </head> <body> <% Object message = request.getAttribute("message"); if(message!=null && !"".equals(message)){ %> <script type="text/javascript"> alert("<%=request.getAttribute("message")%>"); </script> <%} %> <div align="center"> <h1 style="color: red;">添加用户</h1> <form action="CEServlet?method=Cadd" method="post" onsubmit="return check()"> <div class="a"> 用户名<input type="text" id="user" name="user"/> </div> <div class="a"> 密码<input type="password" id="passward" name="passward" /> </div> <div class="a"> 类型<input type="text" id="zhiwu" name="zhiwu"/> </div> <div class="a"> <button type="submit" class="b">保 存</button> </div> <div class="a"> <a href="index.jsp" >返回</a> </div> </form> </div> </body> </html>
package ceyan; import java.sql.Connection; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import java.util.ArrayList; import java.util.List; import xuexi.Bill; import xuexi.DBUtil; public class CEDao { public boolean add(users user1) { String sql = "insert into (user,passward,zhiwu) values ('" + user1.getUser() + "','" + user1.getPassward() + "','"+user1.getZhiwu()+"')"; Connection conn = DBUtil.getConn();//调用方法连接数据库 Statement state = null; boolean f = false; int a = 0 ; try { //监视大括号内的代码 state = conn.createStatement(); a = state.executeUpdate(sql); } catch (Exception e) { //捕获错误 e.printStackTrace(); } finally { //关闭z 连接 DBUtil.close(state, conn); } if (a > 0) { f = true; } return f; } } //DBUtil.java package ceyan; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class CEConnection { public static String db_url = "jdbc:mysql://localhost:3306 /roo1?useSSL=false&serverTimezone=GMT"; public static String db_user = "root";//账号 public static String db_pass = "123456";//密码 public static Connection getConn () { Connection conn = null; try { Class.forName("com.mysql.cj.jdbc.Driver"); conn = DriverManager.getConnection(db_url, db_user, db_pass); } catch (Exception e) { e.printStackTrace(); } return conn; } public static void close (Statement state, Connection conn) { if (state != null) { try { state.close(); } catch (SQLException e) { e.printStackTrace(); } } if (conn != null) { try { conn.close(); } catch (SQLException e) { e.printStackTrace(); } } } public static void close (ResultSet rs, Statement state, Connection conn) { if (rs != null) { try { rs.close(); } catch (SQLException e) { e.printStackTrace(); } } if (state != null) { try { state.close(); } catch (SQLException e) { e.printStackTrace(); } } if (conn != null) { try { conn.close(); } catch (SQLException e) { e.printStackTrace(); } } } }