使用 MySQL 數據庫登錄 Java
[英]Java login with MySQL database
問題描述
您好，目前我無法使用 SQL 語句登錄 MySQL 數據庫並打開下一個 MenuForm。 不知道有什么問題。 沒有錯誤。 我添加了額外的 if "//if(password.contains("123") && username.contains("test")) {" 來檢查它是否有效，它確實有效，但仍然無法與 MySQL 進行比較。
private void jButton_LoginActionPerformed(java.awt.event.ActionEvent evt) {
PreparedStatement st;
ResultSet rs;
// get the username & password
String username = jTextField_Username.getText();
String password = String.valueOf(jPasswordField.getPassword());
//create a select query to check if the username and the password exist in the database
String query = "SELECT * FROM users_db.users WHERE 'username' = ? and 'password' = ?";
try {
st = My_CNX.getConnection().prepareStatement(query);
st.setString(1, username);
st.setString(2, password);
rs = st.executeQuery();
//if(password.contains("123") && username.contains("test")) {
if(rs.next()){
// show a new form
MenuForm form = new MenuForm();
form.setVisible(true);
form.pack(); // rozmiarem ma się zająć automatycznie manager rozmiaru? druga opcja to ustalenie romziaru x i y, za pomocą innej funkcji
form.setLocationRelativeTo(null);
//close the current form(login form)
form.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.dispose();
}else{
// error message
JOptionPane.showMessageDialog(null, "Invalid Username or Password", "Login Error",2);
}
} catch (SQLException ex) {
Logger.getLogger(Login_Form.class.getName()).log(Level.SEVERE, null, ex);
}
}
我在這里添加了完整的代碼。 我在下面包含了整個登錄表單。
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package Login_register_design;
import java.awt.Color;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.swing.border.Border;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JOptionPane;
/**
*
* @author tomas
*/
public class Login_Form extends javax.swing.JFrame {
/**
* Creates new form Login_Form
*/
public Login_Form() {
initComponents();
/* - Downalod The Connector For Java & MySQL database*/
/* Link -> https://dev.mysql.com/downloads/connector/j/ */
/* OPEN */
/*Create a connection with the database */
// Center the form
this.setLocationRelativeTo(null);
// create a yellow border for the panel_title
// 0 border in the top
Border jpanel_title_border = BorderFactory.createMatteBorder(1, 1, 1, 1, Color.blue);
// set the border to the jpanel_title
jPanel_title.setBorder(jpanel_title_border);
// create a orange border for the global panel
Border global_panel_border = BorderFactory.createMatteBorder(1, 1, 1, 1, Color.orange);
jPanel5.setBorder(global_panel_border);
// create a black border for the close & minimize jlables
Border label_border = BorderFactory.createMatteBorder(1, 1, 1, 1, Color.black);
jLabel_minimize.setBorder(label_border);
jLabel_close.setBorder(label_border);
// create border for the username and password field
Border field_border = BorderFactory.createMatteBorder(1, 5, 1, 1, Color.white);
jTextField_Username.setBorder(field_border);
jPasswordField.setBorder(field_border);
}
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jPanel1 = new javax.swing.JPanel();
jPanel5 = new javax.swing.JPanel();
jPanel2 = new javax.swing.JPanel();
jPanel4 = new javax.swing.JPanel();
jLabel_username = new javax.swing.JLabel();
jLabel_password = new javax.swing.JLabel();
jTextField_Username = new javax.swing.JTextField();
jPasswordField = new javax.swing.JPasswordField();
jButton_Login = new javax.swing.JButton();
jPanel3 = new javax.swing.JPanel();
jLabel_minimize = new javax.swing.JLabel();
jLabel_close = new javax.swing.JLabel();
jPanel_title = new javax.swing.JPanel();
jLabel3 = new javax.swing.JLabel();
jPanel1.setForeground(new java.awt.Color(0, 255, 153));
javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
jPanel1.setLayout(jPanel1Layout);
jPanel1Layout.setHorizontalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 462, Short.MAX_VALUE)
);
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 330, Short.MAX_VALUE)
);
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setUndecorated(true);
jPanel2.setBackground(new java.awt.Color(0, 204, 204));
jLabel_username.setIcon(new javax.swing.ImageIcon(getClass().getResource("/grafika/Loginemail-100px.png"))); // NOI18N
jLabel_password.setIcon(new javax.swing.ImageIcon(getClass().getResource("/grafika/Hasło-100px.png"))); // NOI18N
jTextField_Username.setFont(new java.awt.Font("Tahoma", 0, 18)); // NOI18N
jTextField_Username.setForeground(new java.awt.Color(153, 153, 153));
jTextField_Username.setText("username");
jTextField_Username.addFocusListener(new java.awt.event.FocusAdapter() {
public void focusGained(java.awt.event.FocusEvent evt) {
jTextField_UsernameFocusGained(evt);
}
public void focusLost(java.awt.event.FocusEvent evt) {
jTextField_UsernameFocusLost(evt);
}
});
jTextField_Username.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jTextField_UsernameActionPerformed(evt);
}
});
jPasswordField.setFont(new java.awt.Font("Tahoma", 0, 18)); // NOI18N
jPasswordField.setForeground(new java.awt.Color(153, 153, 153));
jPasswordField.setText("password");
jPasswordField.addFocusListener(new java.awt.event.FocusAdapter() {
public void focusGained(java.awt.event.FocusEvent evt) {
jPasswordFieldFocusGained(evt);
}
public void focusLost(java.awt.event.FocusEvent evt) {
jPasswordFieldFocusLost(evt);
}
});
jButton_Login.setBackground(new java.awt.Color(0, 84, 140));
jButton_Login.setFont(new java.awt.Font("Microsoft Sans Serif", 0, 24)); // NOI18N
jButton_Login.setForeground(new java.awt.Color(255, 255, 255));
jButton_Login.setText("Login");
jButton_Login.setCursor(new java.awt.Cursor(java.awt.Cursor.HAND_CURSOR));
jButton_Login.addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseEntered(java.awt.event.MouseEvent evt) {
jButton_LoginMouseEntered(evt);
}
public void mouseExited(java.awt.event.MouseEvent evt) {
jButton_LoginMouseExited(evt);
}
});
jButton_Login.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton_LoginActionPerformed(evt);
}
});
jPanel3.setBackground(new java.awt.Color(0, 153, 153));
javax.swing.GroupLayout jPanel3Layout = new javax.swing.GroupLayout(jPanel3);
jPanel3.setLayout(jPanel3Layout);
jPanel3Layout.setHorizontalGroup(
jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 0, Short.MAX_VALUE)
);
jPanel3Layout.setVerticalGroup(
jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 0, Short.MAX_VALUE)
);
javax.swing.GroupLayout jPanel4Layout = new javax.swing.GroupLayout(jPanel4);
jPanel4.setLayout(jPanel4Layout);
jPanel4Layout.setHorizontalGroup(
jPanel4Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel4Layout.createSequentialGroup()
.addGap(24, 24, 24)
.addGroup(jPanel4Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(jButton_Login, javax.swing.GroupLayout.PREFERRED_SIZE, 382, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGroup(jPanel4Layout.createSequentialGroup()
.addComponent(jLabel_password)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jPasswordField, javax.swing.GroupLayout.PREFERRED_SIZE, 278, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(jPanel4Layout.createSequentialGroup()
.addComponent(jLabel_username)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jTextField_Username, javax.swing.GroupLayout.PREFERRED_SIZE, 279, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addContainerGap(24, Short.MAX_VALUE))
.addGroup(jPanel4Layout.createSequentialGroup()
.addGap(174, 174, 174)
.addComponent(jPanel3, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addContainerGap())
);
jPanel4Layout.setVerticalGroup(
jPanel4Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel4Layout.createSequentialGroup()
.addGap(45, 45, 45)
.addGroup(jPanel4Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(jTextField_Username)
.addComponent(jLabel_username, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jPanel3, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(jPanel4Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(jLabel_password, javax.swing.GroupLayout.PREFERRED_SIZE, 47, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jPasswordField))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jButton_Login, javax.swing.GroupLayout.PREFERRED_SIZE, 46, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(53, Short.MAX_VALUE))
);
// set icon to the jlabel
// set icon to the jlabel
jLabel_minimize.setFont(new java.awt.Font("Tahoma", 1, 24)); // NOI18N
jLabel_minimize.setText("-");
jLabel_minimize.setCursor(new java.awt.Cursor(java.awt.Cursor.HAND_CURSOR));
jLabel_minimize.setPreferredSize(new java.awt.Dimension(17, 29));
jLabel_minimize.addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseClicked(java.awt.event.MouseEvent evt) {
jLabel_minimizeMouseClicked(evt);
}
public void mouseEntered(java.awt.event.MouseEvent evt) {
jLabel_minimizeMouseEntered(evt);
}
public void mouseExited(java.awt.event.MouseEvent evt) {
jLabel_minimizeMouseExited(evt);
}
});
jLabel_close.setFont(new java.awt.Font("Arial", 1, 18)); // NOI18N
jLabel_close.setText("X");
jLabel_close.setCursor(new java.awt.Cursor(java.awt.Cursor.HAND_CURSOR));
jLabel_close.addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseClicked(java.awt.event.MouseEvent evt) {
jLabel_closeMouseClicked(evt);
}
public void mouseEntered(java.awt.event.MouseEvent evt) {
jLabel_closeMouseEntered(evt);
}
public void mouseExited(java.awt.event.MouseEvent evt) {
jLabel_closeMouseExited(evt);
}
});
jPanel_title.setBackground(new java.awt.Color(51, 153, 255));
jLabel3.setBackground(new java.awt.Color(51, 153, 255));
jLabel3.setFont(new java.awt.Font("Arial", 1, 48)); // NOI18N
jLabel3.setForeground(new java.awt.Color(255, 255, 255));
jLabel3.setText("Login");
javax.swing.GroupLayout jPanel_titleLayout = new javax.swing.GroupLayout(jPanel_title);
jPanel_title.setLayout(jPanel_titleLayout);
jPanel_titleLayout.setHorizontalGroup(
jPanel_titleLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel_titleLayout.createSequentialGroup()
.addGap(40, 40, 40)
.addComponent(jLabel3)
.addContainerGap(42, Short.MAX_VALUE))
);
jPanel_titleLayout.setVerticalGroup(
jPanel_titleLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel_titleLayout.createSequentialGroup()
.addComponent(jLabel3, javax.swing.GroupLayout.PREFERRED_SIZE, 52, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(0, 10, Short.MAX_VALUE))
);
javax.swing.GroupLayout jPanel2Layout = new javax.swing.GroupLayout(jPanel2);
jPanel2.setLayout(jPanel2Layout);
jPanel2Layout.setHorizontalGroup(
jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel2Layout.createSequentialGroup()
.addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel2Layout.createSequentialGroup()
.addGap(118, 118, 118)
.addComponent(jPanel_title, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(57, 57, 57)
.addComponent(jLabel_minimize, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jLabel_close))
.addGroup(jPanel2Layout.createSequentialGroup()
.addContainerGap()
.addComponent(jPanel4, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addContainerGap(14, Short.MAX_VALUE))
);
jPanel2Layout.setVerticalGroup(
jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel2Layout.createSequentialGroup()
.addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel2Layout.createSequentialGroup()
.addGap(11, 11, 11)
.addComponent(jPanel_title, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(jPanel2Layout.createSequentialGroup()
.addGap(18, 18, 18)
.addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel_close)
.addComponent(jLabel_minimize, javax.swing.GroupLayout.PREFERRED_SIZE, 22, javax.swing.GroupLayout.PREFERRED_SIZE))))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 31, Short.MAX_VALUE)
.addComponent(jPanel4, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap())
);
javax.swing.GroupLayout jPanel5Layout = new javax.swing.GroupLayout(jPanel5);
jPanel5.setLayout(jPanel5Layout);
jPanel5Layout.setHorizontalGroup(
jPanel5Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel5Layout.createSequentialGroup()
.addGap(22, 22, 22)
.addComponent(jPanel2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(23, Short.MAX_VALUE))
);
jPanel5Layout.setVerticalGroup(
jPanel5Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel5Layout.createSequentialGroup()
.addGap(20, 20, 20)
.addComponent(jPanel2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(19, Short.MAX_VALUE))
);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jPanel5, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jPanel5, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
);
pack();
}// </editor-fold>
private void jLabel_minimizeMouseEntered(java.awt.event.MouseEvent evt) {
Border label_border = BorderFactory.createMatteBorder(1, 1, 1, 1, Color.white);
jLabel_minimize.setBorder(label_border);
jLabel_minimize.setForeground(Color.white);
}
private void jLabel_minimizeMouseExited(java.awt.event.MouseEvent evt) {
Border label_border = BorderFactory.createMatteBorder(1, 1, 1, 1, Color.black);
jLabel_minimize.setBorder(label_border);
jLabel_minimize.setForeground(Color.black);
}
private void jLabel_closeMouseEntered(java.awt.event.MouseEvent evt) {
Border label_border = BorderFactory.createMatteBorder(1, 1, 1, 1, Color.white);
jLabel_close.setBorder(label_border);
jLabel_close.setForeground(Color.white);
}
private void jLabel_closeMouseExited(java.awt.event.MouseEvent evt) {
Border label_border = BorderFactory.createMatteBorder(1, 1, 1, 1, Color.black);
jLabel_close.setBorder(label_border);
jLabel_close.setForeground(Color.black);
}
private void jTextField_UsernameFocusGained(java.awt.event.FocusEvent evt) {
// clear the testfield on focus if the text is "username"
if(jTextField_Username.getText().trim().toLowerCase().equals("username"));
{
jTextField_Username.setText("");
jTextField_Username.setForeground(Color.black);
}
Border jpanel_icon = BorderFactory.createMatteBorder(1, 1, 1, 1, Color.blue);
jLabel_username.setBorder(jpanel_icon);
}
private void jTextField_UsernameFocusLost(java.awt.event.FocusEvent evt) {
// if the text field is equal to username or empty
// we will set the "username" text in the field on
// on focus lost event
if(jTextField_Username.getText().trim().equals("") ||
jTextField_Username.getText().trim().toLowerCase().equals("username"))
{
jTextField_Username.setText("username");
jTextField_Username.setForeground(new Color(153,153,153));
}
// create a border with the color of the parent jpanel for the icons label to remove the move
Border label_icons_border = BorderFactory.createMatteBorder(1, 1, 1, 1, new Color(153,153,153));
jLabel_username.setBorder(label_icons_border);
}
private void jPasswordFieldFocusGained(java.awt.event.FocusEvent evt) {
// clear the password on focus if the text is "password"
// get the password text
String pass = String.valueOf(jPasswordField.getPassword());
if(pass.trim().toLowerCase().equals("password"));
{
jPasswordField.setText("");
jPasswordField.setForeground(Color.black);
}
// set a yellow border to the jlabel icon
Border jpanel_icon = BorderFactory.createMatteBorder(1, 1, 1, 1, Color.blue);
// set the border to the jpanel_title
jLabel_password.setBorder(jpanel_icon);
}
private void jPasswordFieldFocusLost(java.awt.event.FocusEvent evt) {
// get the password text
String pass = String.valueOf(jPasswordField.getPassword());
if(pass.trim().equals("") ||
pass.trim().toLowerCase().equals("password"))
{
jPasswordField.setText("password");
jPasswordField.setForeground(new Color(153,153,153));
}
// create a border with the color of the parent jpanel for the icons label to remove the move
Border label_icons_border = BorderFactory.createMatteBorder(1, 1, 1, 1, new Color(153,153,153));
jLabel_password.setBorder(label_icons_border);
}
private void jButton_LoginActionPerformed(java.awt.event.ActionEvent evt) {
PreparedStatement st;
ResultSet rs;
// get the username & password
String username = jTextField_Username.getText();
String password = String.valueOf(jPasswordField.getPassword());
//create a select query to check if the username and the password exist in the database
String query = "SELECT * FROM users_db.users WHERE 'username' = ? and 'password' = ?";
try {
st = My_CNX.getConnection().prepareStatement(query);
st.setString(1, username);
st.setString(2, password);
rs = st.executeQuery();
//if(password.contains("123") && username.contains("test")) {
if(rs.next()){
// show a new form
MenuForm form = new MenuForm();
form.setVisible(true);
form.pack(); // rozmiarem ma się zająć automatycznie manager rozmiaru? druga opcja to ustalenie romziaru x i y, za pomocą innej funkcji
form.setLocationRelativeTo(null);
//close the current form(login form)
form.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.dispose();
}else{
// error message
JOptionPane.showMessageDialog(null, "Invalid Username or Password", "Login Error",2);
}
} catch (SQLException ex) {
Logger.getLogger(Login_Form.class.getName()).log(Level.SEVERE, null, ex);
}
}
private void jButton_LoginMouseEntered(java.awt.event.MouseEvent evt) {
//set jbutton backbround
jButton_Login.setBackground(new Color(0, 101, 183));
}
private void jButton_LoginMouseExited(java.awt.event.MouseEvent evt) {
//set jbutton backbround
jButton_Login.setBackground(new Color(0, 84, 104));
}
private void jLabel_minimizeMouseClicked(java.awt.event.MouseEvent evt) {
this.setState(JFrame.ICONIFIED);
}
private void jLabel_closeMouseClicked(java.awt.event.MouseEvent evt) {
System.exit(0);
}
private void jTextField_UsernameActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
}
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(Login_Form.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(Login_Form.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(Login_Form.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(Login_Form.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Login_Form().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton jButton_Login;
private javax.swing.JLabel jLabel3;
private javax.swing.JLabel jLabel_close;
private javax.swing.JLabel jLabel_minimize;
private javax.swing.JLabel jLabel_password;
private javax.swing.JLabel jLabel_username;
private javax.swing.JPanel jPanel1;
private javax.swing.JPanel jPanel2;
private javax.swing.JPanel jPanel3;
private javax.swing.JPanel jPanel4;
private javax.swing.JPanel jPanel5;
private javax.swing.JPanel jPanel_title;
private javax.swing.JPasswordField jPasswordField;
private javax.swing.JTextField jTextField_Username;
// End of variables declaration
}
1 個解決方案
解決方案1
0 已采納 2020-02-16 16:06:58
代替
"SELECT * FROM users_db.users WHERE 'username' = ? and 'password' = ?"
和
"SELECT * FROM users_db.users WHERE username = ? AND password = ?"
請注意，我已經刪除了包含字段的單引號。
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