我目前正在制作一个 gui 程序，我不知道如何设置我的程序，因此当用户输入用户名和密码，然后单击登录按钮时，它会检查数据库中的用户名和密码，如果用户名和密码在数据库中，则他们接受(如果没有拒绝)。
这是我的欢迎屏幕，目前它很糟糕，我打算清理它。
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
/**
*
* @author
*/
public class Welcome extends JFrame {
private JButton Existing, New, Exit;
private JLabel Welcome, Date, Version;
private JPanel WelcomeP;
private JMenuItem jmiNew, jmiExisting, jmiExit, jmiAbout;
public Welcome() {
//create menu bar
JMenuBar regMenuBar = new JMenuBar();
//set menu bar to the applet
setJMenuBar(regMenuBar);
//add menu "operation" to menu bar
JMenu optionsMenu = new JMenu("Options");
optionsMenu.setMnemonic('O');
regMenuBar.add(optionsMenu);
//add menu "help"
JMenu helpMenu = new JMenu("Help");
helpMenu.setMnemonic('H');
helpMenu.add(jmiAbout = new JMenuItem("About", 'A'));
regMenuBar.add(helpMenu);
//add menu items with mnemonics to menu "options"
optionsMenu.add(jmiNew = new JMenuItem("New", 'N'));
optionsMenu.add(jmiExisting = new JMenuItem("Existing", 'E'));
optionsMenu.addSeparator();
optionsMenu.add(jmiExit = new JMenuItem("Exit", 'E'));
Container c = getContentPane();
c.setLayout(new BorderLayout());
WelcomeP = new JPanel();
WelcomeP.setLayout(new GridLayout(2, 1));
Welcome = new JLabel("Welcome");
Date = new JLabel("Date: 01/10/2013");
Version = new JLabel("Version 0.1");
Exit = new JButton("Exit");
Existing = new JButton("Existing User");
New = new JButton("New User");
WelcomeP.add(Welcome);
WelcomeP.add(Date);
WelcomeP.add(Version);
WelcomeP.add(Existing);
WelcomeP.add(Exit);
WelcomeP.add(New);
Exit.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.exit(0);
}
});
New.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
registerInterface regFace = new registerInterface();
regFace.setVisible(true);
Welcome.this.dispose();
Welcome.this.setVisible(false);
}
});
Existing.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
log login = new log();
login.setVisible(true);
login.setSize(500, 300);
Welcome.this.dispose();
Welcome.this.setVisible(false);
}
});
jmiExit.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.exit(0);
}
});
jmiNew.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
registerInterface regFace = new registerInterface();
regFace.setVisible(true);
Welcome.this.dispose();
Welcome.this.setVisible(false);
}
});
jmiExisting.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
log shoeFace = new log();
shoeFace.setVisible(true);
shoeFace.setSize(500, 300);
Welcome.this.dispose();
Welcome.this.setVisible(false);
}
});
//listner for about menuitem
jmiAbout.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
JOptionPane.showMessageDialog(null,
"Program Dedicated to researchers of eAgriculture"
+ "\n Assignment for University",
"About", JOptionPane.INFORMATION_MESSAGE);
}
});
c.add(WelcomeP, BorderLayout.CENTER);
setSize(500, 300);
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public static void main(String[] args) {
Welcome app = new Welcome();
}
}
当我单击现有用户时，它会将我带到登录面板:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
class Login {
// public static void main(String arg[])
// {
// log frame=new log();
// frame.setSize(500,500);
// frame.setLocationRelativeTo(null);
// frame.setVisible(true);
// }
}
class log extends JFrame {
private JTextField jtfUsername, jtfPassword;
private JButton backButton, loginButton;
private JMenuItem jmiLogin, jmiBack, jmiHelp, jmiAbout;
log() {
//create menu bar
JMenuBar jmb = new JMenuBar();
//set menu bar to the applet
setJMenuBar(jmb);
//add menu "operation" to menu bar
JMenu optionsMenu = new JMenu("Options");
optionsMenu.setMnemonic('O');
jmb.add(optionsMenu);
//add menu "help"
JMenu helpMenu = new JMenu("Help");
helpMenu.setMnemonic('H');
helpMenu.add(jmiAbout = new JMenuItem("About", 'A'));
jmb.add(helpMenu);
//add menu items with mnemonics to menu "options"
optionsMenu.add(jmiLogin = new JMenuItem("Login", 'L'));
optionsMenu.addSeparator();
optionsMenu.add(jmiBack = new JMenuItem("Back", 'B'));
//panel p1 to holds text fields
JPanel p1 = new JPanel(new GridLayout(2, 2));
p1.add(new JLabel("Username"));
p1.add(jtfUsername = new JTextField(15));
p1.add(new JLabel("Password"));
p1.add(jtfPassword = new JPasswordField(15));
//panel p2 to holds buttons
JPanel p2 = new JPanel(new FlowLayout());
p2.add(backButton = new JButton("Back"));
p2.add(loginButton = new JButton("Login"));
//Panel with image??????
//add panels to frame
JPanel panel = new JPanel(new GridLayout(2, 1));
panel.add(p1, BorderLayout.CENTER);
panel.add(p2, BorderLayout.SOUTH);
add(panel, BorderLayout.CENTER);
setTitle("Main Page");
//listners for exit menuitem and button
jmiBack.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
Welcome welcome = new Welcome();
welcome.setVisible(true);
welcome.setSize(500, 500);
welcome.setLocationRelativeTo(null);
registerInterface regFace = new registerInterface();
regFace.setVisible(false);
log.this.dispose();
log.this.setVisible(false);
}
});
backButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
Welcome welcome = new Welcome();
welcome.setVisible(true);
welcome.setSize(500, 500);
welcome.setLocationRelativeTo(null);
registerInterface regFace = new registerInterface();
regFace.setVisible(false);
log.this.dispose();
log.this.setVisible(false);
}
});
//listner for about menuitem
jmiAbout.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JOptionPane.showMessageDialog(null,
"This is the login panel"
+ "\n Assignment for University",
"About", JOptionPane.INFORMATION_MESSAGE);
}
});
//action listeners for Login in button and menu item
loginButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
MainMenu mainmenu = new MainMenu();
mainmenu.setVisible(true);
mainmenu.setSize(500, 500);
mainmenu.setLocationRelativeTo(null);
registerInterface regFace = new registerInterface();
regFace.setVisible(false);
log.this.dispose();
log.this.setVisible(false);
}
});
jmiLogin.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
MainMenu mainmenu = new MainMenu();
mainmenu.setVisible(true);
mainmenu.setSize(500, 500);
mainmenu.setLocationRelativeTo(null);
registerInterface regFace = new registerInterface();
regFace.setVisible(false);
log.this.dispose();
log.this.setVisible(false);
}
});
}
}
我已经在netbeans中设置了一个JDBC，并添加了包含用户名和密码的表，并用模拟用户名和密码填充了表，我还想让他们在单击新用户时可以将新信息添加到数据库，以便他们可以长期使用新帐户。
下面是我的 JDBC
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
public class JDBC {
private Connection con = null;
private String query = null;
private ResultSet rs;
private String url = "jdbc:derby://localhost:1527/Assignment";
private String usrName = "root";
private String pwd = "root";
public JDBC() throws Exception {
try {
con = DriverManager.getConnection(url, usrName, pwd);
query = "SELECT USERNAME, PASSWORD from root.PERSON";
PreparedStatement stm = con.prepareStatement(query);
rs = stm.executeQuery();
while (rs.next()) {
String USER = rs.getString("USERNAME");
String PW = rs.getString("PASSWORD");
System.out.println(" USERNAME: " +
USER + " PASSWORD: " + PW);
}
close();
} catch (Exception e) {
}
}
private void close() {
try {
if (rs != null) {
rs.close();
}
if (con != null) {
con.close();
}
} catch (Exception e) {
}
}
public static void main(String[] args) throws Exception {
JDBC dao = new JDBC();
}
}
最佳答案
阅读JDBC Database Access有关 SQL 的信息教程。
编辑:
您为什么要读取所有用户 ID 和密码？对于登录检查，您将查询数据库以查看是否在数据库中找到了在用户 ID/密码文本字段中输入的值。
因此查询将类似于:
query = "select userid from person where userid = ? and password = ?";
PreparedStatement stm = con.prepareStatement(query);
stmt.setString(1, useridTextField.getText());
stmt.setString(2, passwordTextField.getPassword().toString());
因此您的 SQL 方法需要访问文本字段中的数据。
然后，如果 ResultSet 不为空，您就知道您为给定的用户 ID 输入了正确的密码。
再次阅读教程以了解正确的 SQL。
关于java - 如何在 Gui 程序中实现 JDBC 数据库以验证登录程序的用户和密码，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/18928921/