我想制作一个银行管理系统，所以我编写了所有代码，但最后一个代码（使用带有jdbc数据库活动的html表）不起作用，所以我的程序不起作用，这是我的代码
Userdb.java =
public class Userdb {
public ArrayList<User> getAllUser() throws SQLException{
ArrayList<User> users = new ArrayList<User>();
String query = "Select firstName,password from login";
DbHelper db = new DbHelper();
try {
Connection connection = db.getConnection();
PreparedStatement statement = connection.prepareStatement(query);
ResultSet resultSet = statement.executeQuery();
while(resultSet.next()) {
int id = resultSet.getInt("id");
String name = resultSet.getString("name");
String surname = resultSet.getString("surname");
String username = resultSet.getString("username");
String password = resultSet.getString("password");
String email = resultSet.getString("email");
User user = new User(id,name,surname,username,password,email);
users.add(user);
}
}catch(SQLException e) {
db.getErrorMessages(e);
}
return users;
}
DbHelper.java =
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class DbHelper {
public Connection getConnection() throws SQLException{
String dbUrl = "jdbc:mysql://localhost:3306/classicmodels";
String name = "root";
String password = "1234";
return DriverManager.getConnection(dbUrl,name,password);
}
public void getErrorMessages(SQLException e) {
System.out.println("Error Code : "+e.getErrorCode());
System.out.println("Error Messages : "+e.getMessage());
}
}
用户.java =
public class User {
private int id;
private String name;
private String surname;
private String username;
private String password;
private String email;
public User() {
}
public User(int id,String name,String surname,String username,String password,String email) {
this.setId(id);
this.setName(name);
this.setSurname(surname);
this.setUsername(username);
this.setPassword(password);
this.setEmail(email);
}
public void setId(int id) {
this.id = id;
}
public void setName(String name) {
this.name = name;
}
public void setSurname(String surname) {
this.surname = surname;
}
public void setUsername(String username) {
this.username = username;
}
public void setPassword(String password) {
this.password = password;
}
public void setEmail(String email) {
this.email = email;
}
public int getId() {
return id;
}
public String getName() {
return name;
}
public String getSurname() {
return surname;
}
public String getUsername() {
return username;
}
public String getEmail() {
return email;
}
public String getPassword() {
return password;
}
}
登录成功管理.jsp =
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%@ page import="java.util.*" %>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Admin Panel</title>
<!-- Bootstrap CSS -->
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css">
<!-- Font Awesome -->
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.15.1/css/all.min.css">
<style>
table {
border-collapse: collapse;
width: 100%;
}
th, td {
border: 1px solid #dddddd;
text-align: left;
padding: 8px;
}
th {
background-color: #f2f2f2;
}
</style>
</head>
<body>
<!-- Navbar -->
<nav class="navbar navbar-expand-lg navbar-dark bg-dark">
<a class="navbar-brand" href="#">Admin Panel</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav"
aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarNav">
<ul class="navbar-nav ml-auto">
<li class="nav-item">
<a class="nav-link" href="loginPage.jsp"><i class="fas fa-sign-out-alt fa-lg"></i> Logout</a>
</li>
</ul>
</div>
</nav>
<!-- Orta Alan -->
<div class="container-fluid d-flex justify-content-center align-items-center h-100">
<div class="row">
<h1>User List</h1>
<form action="AdminServlet" method="post">
<table class="table">
<thead>
<tr>
<th>ID</th>
<th>Name</th>
<th>Surname</th>
<th>Username</th>
<th>Email</th>
</tr>
</thead>
<tbody>
<%
Userdb userdb = new Userdb();
ArrayList<User> users = userdb.getAllUser();
for (User user : users) {
%>
<tr>
<td><%= user.getId() %></td>
<td><%= user.getName() %></td>
<td><%= user.getSurname() %></td>
<td><%= user.getUsername() %></td>
<td><%= user.getEmail() %></td>
</tr>
<% } %>
</tbody>
</table>
</form>
</div>
</div>
<!-- Bootstrap JS ve jQuery -->
<script src="https://code.jquery.com/jquery-3.5.1.slim.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/@popperjs/[email protected]/dist/umd/popper.min.js"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js"></script>
</body>
</html>
我保证我的数据库工作完美，问题不是由数据库引起的，你们有什么建议给我吗？
JSP 代码无法编译，因为您没有通过
UserdbUser@page import第二个问题是在方法
UserdbgetAllUser()ConnectionAutoClosableStatementResultSettry (Connection connection = db.getConnection();) {
//your code here
}catch(SQLException e) {
db.getErrorMessages(e);
}