Task
1. Complete the user login module by connecting to the database.
2. After successful login, query the contents of a database table; if the login is unsuccessful, return to the login page.
3. There must be verification of null values and illegal characters on the page end.
4. After successful login, add, delete, modify and query data in a table.
code
Database related code
Create database
The name is jdbcHomework and the character encoding is utf8
Database creation table
Student table
DROP TABLE IF EXISTS `student`;
CREATE TABLE `student` (
`Sid` char(11) CHARACTER SET utf8 NOT NULL,
`Sname` char(50) CHARACTER SET utf8 DEFAULT NULL,
`Ssex` char(2) CHARACTER SET utf8 DEFAULT NULL,
`Sclass` char(50) CHARACTER SET utf8 DEFAULT NULL,
`Syuanxi` char(50) CHARACTER SET utf8 DEFAULT NULL,
PRIMARY KEY (`Sid`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 COMMENT='jdbc作业';
user table
DROP TABLE IF EXISTS `user`;
CREATE TABLE `user` (
`Userid` char(11) NOT NULL,
`Username` char(50) DEFAULT NULL,
`Userpwd` varchar(12) DEFAULT NULL,
PRIMARY KEY (`Userid`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='jdbc作业';
Insert data into database table
Student table
INSERT INTO `student` VALUES ('20221104122', '李静静', '女', '计科（专升本）1班', '计算机');
INSERT INTO `student` VALUES ('20221104204', '柯柯', '女', '计科（专升本）2班', '计算机');
INSERT INTO `student` VALUES ('20221104250', 'zyp', '男', '自动化1班', '自动化');
user table
INSERT INTO `user` VALUES ('20221104122', '洛可可', '666666');
INSERT INTO `user` VALUES ('root', '洛可可', 'root');
code in myeclipse
Code in the jdbcHomework package of src
Function: connect to database
1.LinkMysql.java is the code for connecting to mysql, including driver, password, url, and is used for background processing of login interface, login check, addition, deletion, modification and check
2.ConnectionFactory. java is the code for connecting to mysql, including driver, password, and url, which is used to connect to the database through the interface linkMysql.jsp after successful login
3. The method of using the above class in this study is through the id of javaBean Get the link to connect to the database; the method for using the following class is to import the class at the beginning, create a new class in the code and use the "new class name.getConnection();" method to get the link to connect to the database
1．LinkMysql
package jdbcHomework;
import java.sql.*;
public class LinkMysql {
//驱动程序
private String driverName = "com.mysql.jdbc.Driver";
//设置数据库连接URL
private String url = "jdbc:mysql://localhost:3306/jdbcHomework?useUnicode=true&characterEncoding=utf-8";
private String user = "root";//数据库登录用户名
private String password = "root";//数据库登录密码
public String getDriverName() {
return driverName;
}
public void setDriverName(String driverName) {
this.driverName = driverName;
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public String getUser() {
return user;
}
public void setUser(String user) {
this.user = user;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public Connection getConnection() {
try {
Class.forName(driverName);
return DriverManager.getConnection(url, user, password);
} catch (Exception e) {
//e.printStackTrace();
System.out.println("驱动异常");
return null;
}
}
}
2.ConnectionFactory
package jdbcHomework;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class ConnectionFactory {
private String driverClassName = "com.mysql.jdbc.Driver";
private String url = "jdbc:mysql://localhost:3306/jdbcHomework?useUnicode=true&characterEncoding=utf-8";
private String userName = "root";
private String password = "root";
/*
private static ConnectionFactory connectionFactory=null;
private ConnectionFactory() {
try {
Class.forName(driverClassName);
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public ConnectionFactory(){
}
*/
public Connection getConnection() throws SQLException
{
try {
Class.forName(driverClassName);
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
//e.printStackTrace();
System.out.println("驱动异常");
}
return DriverManager.getConnection(url, userName, password);
}
/*
public static ConnectionFactory getInstance()
{
if (null==connectionFactory) {
connectionFactory=new ConnectionFactory();
}
return connectionFactory;
}
*/
}
Code under WebRoot/jdbcHomework
1. Log in to the main interface code
login.jsp
<%@ page language="java" import="java.util.*,java.sql.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP 'login.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
<script type="text/javascript">
function checkForm(){
if (form1.id.value == null || form1.userid.value==""){
alert("请输入学号");
return false ;
}
if (form1.name.value == null || form1.username.value==""){
alert("请输入姓名");
return false ;
}
if (form1.pwd.value == null || form1.pwd.value==""){
alert("请输入密码");
return false;
}
return true;
}
</script>
</head>
<body bgcolor="pink">
<div class="top" align="center">
<h1>欢迎来到洛可可学生管理系统！！</h1>
</div>
<div class="center" align="center">
<table border="1" bgcolor="rgb(248, 169, 182)">
<form name="form1" action="logincheck.jsp" method="post" onsubmit="return checkForm();">
<tr>
<td>学号：</td>
<td><input type="text" name="id" ></td>
</tr>
<tr>
<td>姓名：</td>
<td><input type="text" name="name" ></td>
</tr>
<tr>
<td>密码：</td>
<td width="50"><input type="password" name="pwd"></td>
</tr>
<tr >
<td colspan="2" align="center">
<input type="submit" value="登录"/>
<input type="reset"/>
</td>
</tr>
</form>
</table>
</div>
<div class="bottom" align="center">
</div>
</body>
</html>
2. Log in to check the code
logincheck.jsp
<%@ page language="java" import="java.util.*,java.sql.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP 'logincheck.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<jsp:useBean id="link" class="jdbcHomework.LinkMysql"></jsp:useBean>
<%
/*获取到login.jsp页面登录时学生的学号、姓名、密码*/
request.setCharacterEncoding("utf-8");
String studentId = request.getParameter("id");
String studentName = request.getParameter("name");
String pwd = request.getParameter("pwd");
System.out.println("学号："+studentId+"，姓名："+studentName+"，密码："+pwd); //控制台输出获取到的登录时学生的学号、姓名、密码
/*连接数据库并执行相关操作*/
Connection con=null;
PreparedStatement ps=null;
ResultSet rs=null;
con = link.getConnection();
String sql="select * from user where Userid=? and Username=? and Userpwd=?";
ps=con.prepareStatement(sql);
ps.setString(1,studentId);
ps.setString(2, studentName);
ps.setString(3,pwd);
rs=ps.executeQuery();
if(rs.next()){
System.out.println("登录成功！");
response.sendRedirect("linkMysql-2.jsp");
}
else{
System.out.println("登录失败！");
response.sendRedirect("login.jsp");
out.print("<script type='javascript'> alert('登陆失败,请重新登录！！');window.location='login.jsp';</script>");
}
rs.close();
ps.close();
con.close();
%>
</body>
</html>
3. Login success page code
linkMysql-2.jsp
<%@ page language="java" import="java.util.*, java.sql.*,jdbcHomework.ConnectionFactory" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP 'linkMysql.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<%-- 在浏览器上显示所有学生信息 --%>
<body bgcolor="pink">
<div class="top" align="center" >
<h1>欢迎加入到洛可可学生管理系统</h1>
</div>
<div class="center" align="center">
<table border="1" bgcolor="rgb(248, 169, 182)" align="center">
<tr>
<th width="87" align="center">学号</th>
<th width="87" align="center">姓名</th>
<th width="87" align="center">性别</th>
<th width="87" align="center">班级</th>
<th width="87" align="center">院系</th>
<th width="87" align="center">操作</th>
</tr>
<%
Connection con= null;
Statement stmt=null;
ResultSet rs=null;
//Class.forName("com.mysql.jdbc.Driver");
/*3306为端口号，student为数据库名，url后面加的?useUnicode=true&characterEncoding=gbk是为了处理向数据库中添加数据时出现乱码的问题。*/
//String url="jdbc:mysql://localhost:3306/jdbcHomework?useUnicode=true&characterEncoding=utf-8";
//con=DriverManager.getConnection(url,"root","root");
ConnectionFactory cf = new ConnectionFactory();
con = cf.getConnection();;
int intPageSize; //一页显示的记录数
int intRowCount; //记录总数
int intPageCount; //总页数
int intPage; // 待显示页码
String strPage;
int i;
intPageSize=10; //设置一页显示的记录数
strPage = request.getParameter("page");
if(strPage==null){
//表明page的参数值为空，此时显示第一页数据
intPage = 1;
}else{
//将字符串转换成整型
intPage = java.lang.Integer.parseInt(strPage);
if(intPage<1)
intPage=1;
}
stmt=con.createStatement();
String sql="select * from student";
rs=stmt.executeQuery(sql);
while(rs.next()){
%>
<tr>
<td><%=rs.getString("Sid")%></td>
<td><%=rs.getString("Sname")%></td>
<td><%=rs.getString("Ssex")%></td>
<td><%=rs.getString("Sclass")%></td>
<td><%=rs.getString("Syuanxi")%></td>
<td><a href="deleteStu.jsp?Sid=<%=rs.getString("Sid")%>">删除</a>
<a href="updateStu.jsp?Sid=<%=rs.getString("Sid")%>">修改</a></td>
</tr>
<%}
rs.close();
stmt.close();
con.close();
%>
</table>
</div>
<br>
<div class="bottom" align="center">
<a href="add.jsp">添加学生信息</a>
<a href="login.jsp">登录界面</a>
</div>
</body>
</html>
4. Delete the student information main interface code
deleteStu.jsp
<%@ page language="java" import="java.util.*,java.sql.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP 'deleteStu.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<jsp:useBean id="link" class="jdbcHomework.LinkMysql"></jsp:useBean>
<%
request.setCharacterEncoding("utf-8");
String sid = request.getParameter("Sid");
System.out.println(sid);
Connection con=null;
PreparedStatement ps=null;
//ResultSet rs=null;
con = link.getConnection();
String sql="delete from student where Sid=? ";
ps=con.prepareStatement(sql);
ps.setString(1,sid);
int i=ps.executeUpdate();
if(i>0){
System.out.println("删除成功！");
response.sendRedirect("linkMysql.jsp");
//out.print("<script type='javascript'> alert('删除成功！');window.location='linkMysql.jsp';</script>");
}
else{
System.out.println("删除的学生不存在！");
response.sendRedirect("linkMysql.jsp");
//out.print("<script type='javascript'> alert('删除失败！');window.location='login.jsp';</script>");
}
ps.close();
con.close();
%>
</body>
</html>
5. Modify the student information main interface code
deleteStu.jsp
<%@ page language="java" import="java.util.*, java.sql.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP 'updateStu.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body bgcolor="pink">
<div class="top" align="center">
<h1>欢迎来到洛可可学生系统修改（更新）页面</h1>
</div>
<hr>
<div class="center" align="center">
<jsp:useBean id="link" class="jdbcHomework.LinkMysql"></jsp:useBean>
<%
String sid = request.getParameter("Sid");
System.out.println(sid);
Connection con=null;
PreparedStatement ps=null;
con=link.getConnection();
String sql="select * from student where Sid=? ";
ps=con.prepareStatement(sql);
ps.setString(1,sid);
ResultSet rs=ps.executeQuery();
if(rs.next()){
%>
<form action="doupdate.jsp" method="post" >
<table border="1" bgcolor="rgb(248, 169, 182)" >
<tr>
<th>学号：</th>
<td><%=rs.getString(1) %></td>
</tr>
<tr>
<th>姓名：</th>
<td><input type="text" name="sname" value="<%=rs.getString(2) %>"></td>
</tr>
<tr>
<th>性别：</th>
<td><input type="text" name="ssex" value="<%=rs.getString(3) %>"></td>
</tr>
<tr>
<th>班级：</th>
<td><input type="text" name="banji" value="<%=rs.getString(4) %>"></td>
</tr>
<tr>
<th>院系：</th>
<td><input type="text" name="yuanxi" value="<%=rs.getString(5) %>"></td>
</tr>
</table>
<br>
<input type="submit" value="修改完成">
</form>
<%
//out.print("<script type='javascript'> alert('登陆成功！');window.location='linkMysql.jsp';</script>");
}
else{
System.out.println("学生不存在！");
response.sendRedirect("linkMysql.jsp");
//out.print("<script type='javascript'> alert('登录失败！');</script>");
//out.print("<script type='javascript'> alert('登陆失败！');window.location='login.jsp';</script>");
}
rs.close();
ps.close();
con.close();
%>
</div>
<hr>
<br>
<div class="bottom" align="center">
<a href="linkMysql-2.jsp">返回上一界面</a>
<a href="login.jsp">登录界面</a>
</div>
</body>
</html>
6. Modify the student information background processing code
doupdate.jsp
<%@ page language="java" import="java.util.*,java.sql.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP 'doupdate.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<jsp:useBean id="link" class="jdbcHomework.LinkMysql"></jsp:useBean>
<%
request.setCharacterEncoding("utf-8");
String uid = request.getParameter("sid");
String uname = request.getParameter("sname");
String sex = request.getParameter("ssex");
String banji = request.getParameter("banji");
String yuanxi = request.getParameter("yuanxi");
System.out.println(uid+uname+sex+banji+yuanxi);
Connection con=null;
PreparedStatement ps=null;
con=link.getConnection();
String sql="update student set Sname=?,Ssex=?,Sclass=?,Syuanxi=? where Sid=?";
ps=con.prepareStatement(sql);
ps.setString(1,uname);
ps.setString(2, sex);
ps.setString(3,banji);
ps.setString(4,yuanxi);
ps.setString(5,uid);
int i=ps.executeUpdate();
if(i>0){
System.out.println("修改成功！");
response.sendRedirect("linkMysql.jsp");
//out.print("<script type='javascript'> alert('学生信息修改成功！');window.location='linkMysql.jsp';</script>");
}
else{
System.out.println("修改失败！");
response.sendRedirect("linkMysql.jsp");
//out.print("<script type='javascript'> alert('学生信息修改失败！');window.location='login.jsp';</script>");
}
ps.close();
con.close();
%>
</body>
</html>
6. Add student information main interface code
add.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP 'add.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
<script type="text/javascript">
function checkForm(){
if (form1.id.value == null || form1.userid.value==""){
alert("请输入学号");
return false ;
}
if (form1.name.value == null || form1.username.value==""){
alert("请输入姓名");
return false ;
}
if (form1.sex.value == null || form1.sex.value==""){
alert("请输入性别");
return false;
}
if (form1.banji.value == null || form1.banji.value==""){
alert("请输入班级");
return false;
}
if (form1.yuanxi.value == null || form1.yuanxi.value==""){
alert("请输入院系");
return false;
}
return true;
}
</script>
</head>
<body bgcolor="pink">
<div class="top" align="center">
<h1>欢迎来到洛可可学生系统添加页面</h1>
</div>
<div class="center" align="center">
<table>
<form name="form1" action="doadd.jsp" method="post" onsubmit="return checkForm();">
<tr>
<td>学号：</td>
<td><input type="text" name="id" ></td>
</tr>
<tr>
<td>姓名：</td>
<td><input type="text" name="name" ></td>
</tr>
<tr>
<td>性别：</td>
<td width="50"><input type="text" name="sex"></td>
</tr>
<tr>
<td>班级：</td>
<td width="50"><input type="text" name="banji"></td>
</tr>
<tr>
<td>院系：</td>
<td width="50"><input type="text" name="yuanxi"></td>
</tr>
<tr >
<td colspan="2" align="center">
<input type="submit" value="添加"/>
<input type="reset"/>
</td>
</tr>
</form>
</table>
</div>
<br>
<div align="center">
<a href="linkMysql-2.jsp">返回上一界面</a>
<a href="login.jsp">切换账号</a>
</div>
</body>
</html>
6. Add student information background processing code
doadd.jsp
<%@ page language="java" import="java.util.*,java.sql.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP 'doadd.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<jsp:useBean id="link" class="jdbcHomework.LinkMysql"></jsp:useBean>
<%
request.setCharacterEncoding("utf-8");
String uid = request.getParameter("id");
String uname = request.getParameter("name");
String sex = request.getParameter("sex");
String banji = request.getParameter("banji");
String yuanxi = request.getParameter("yuanxi");
Connection con=null;
PreparedStatement ps=null;
con = link.getConnection();
String sql="insert into student(Sid,Sname,Ssex,Sclass,Syuanxi) values(?,?,?,?,?)";
ps=con.prepareStatement(sql);
ps.setString(1,uid);
ps.setString(2, uname);
ps.setString(3,sex);
ps.setString(4,banji);
ps.setString(5,yuanxi);
int i=ps.executeUpdate();
if(i>0){
System.out.println("添加成功！");
response.sendRedirect("linkMysql.jsp");
//out.print("<script type='javascript'> alert('添加成功！');window.location='linkMysql.jsp';</script>");
}
else{
System.out.println("添加失败！");
response.sendRedirect("linkMysql.jsp");
//out.print("<script type='javascript'> alert('添加失败！');window.location='login.jsp';</script>");
}
ps.close();
con.close();
%>
</body>
</html>
question
1. When the form receiving address of the login.jsq page is jdbcHomework/logincheck.jsp, only the initial login to the main interface will allow you to enter. Entering correct information through the login interface opened by another interface will report a 404 address error.
2. The form receiving address of the login.jsq page is logincheck.jsp. Effect: Only by entering correct information through the login interface opened by other interfaces will the login success interface be entered. When entering correct information on the initial login interface and clicking login, a 404 error will be reported.
Solution
Solution: <one>Write two login interfaces,
The initial login form acceptance address of the main interface is written as jdbcHomework/logincheck.jsp
The login interface address when jumping to other interfaces is written as logincheck.jsp
<Second>The address is written as the absolute address:/项目名/相对于webroot的相对地址
Effect
Run the initial interface
Entering incorrect user information to log in returns to the login page.
Enter the correct user information to log in to the system
After entering the correct student ID, name, and password, the console outputs that the login is successful, and the page jumps to the login success page (displaying the database student information table)
Delete student information function
There is a delete option after each line of information on the main interface. Click to delete the line of information
Before deletion
After deletion
Modify student information function
There is a modification option after each line of information on the main interface. Click to jump to the page for modifying the information of that line. You can modify the information of the line (student number cannot be changed)
Modify information page
Click on each information (name, gender, class, department) to modify. After the modification is completed, click Modification Complete to jump to the login success interface
Click to return to the previous interface, that is, jump Go to the successful login interface
Click the login interface to jump to the login interface
Add student information function
There is an option to add student information behind the information table on the main interface. Click to jump to the student information adding page. Then enter the information and click Add to complete the function of adding student information.
Student information adding page
Enter the information and click Add to complete the function of adding student information
The console shows that the addition is successful
Click Reset to re-enter< a i=3> Click to return to the previous interface and jump to the login success page Click to switch accounts and jump to the login interface
