将 MySQL 数据显示到 JTextField

Question

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.*;

public class RegistrationForm extends JFrame {
    
    private JPanel panel;
    private JLabel user,pass,id;
    private JTextField user1,pass1,id1;
    private JButton save,signIn;
    public Connection con; 
    public Statement stm; 
    public PreparedStatement pstm;
    
    public RegistrationForm(){
        setTitle("Register Account");
        setLayout(new FlowLayout());

        setContentPane(new JLabel(new ImageIcon("C:\\Users\\RenRen\\Documents\\NetBeansProjects\\JavaConnector\\src\\images\\reg.jpg")));
        
        JLabel sign = new JLabel("Sign Up:");
        sign.setBounds(100,95,80,30);
        sign.setFont(new Font("Login",Font.ITALIC,20));
        
        
        id= new JLabel("User ID");  
        user = new JLabel("Username:");
        pass = new JLabel("Password:");
        JLabel acc = new JLabel("Already have an Account?");
        
        id.setBounds(300,95,80,30);
        user.setBounds(130,140,80,20);
        pass.setBounds(250,140,80,20);
        acc.setBounds(250,230,150,20);
        
        id1 = new JTextField(5);
        user1 = new JTextField(10);
        pass1 = new JPasswordField(10);
        
        id1.setBounds(350,100,80,20);
        user1.setBounds(130,160,110,20);
        pass1.setBounds(250,160,110,20);
        
        save = new JButton("Save");
        signIn = new JButton("Sign In");
        
        save.setBounds(150,200,90,20);
        signIn.setBounds(250,200,90,20);
        
        add(sign);
        add(id);
        add(id1);
       add(user);
        add(user1);
        add(pass);
        add(pass1);
        add(save);
        add(signIn);
       add(acc);
        
       try 
{ 
Class.forName("com.mysql.jdbc.Driver"); 
con=DriverManager.getConnection("jdbc:mysql://localhost:3306/login","root",""); 
stm=con.createStatement();
} 
catch(Exception e) 
{ JOptionPane.showMessageDialog(null, e);
} 
         ActionListener action = new ActionHandler();  
        save.addActionListener(action); 
        
        signIn.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                  //JOptionPane.showMessageDialog(null, "Thank You!");
                dispose();
                LoginMain LM = new LoginMain();
                LM.run();
            }});
               
	
        
        
        }
    private class ActionHandler implements ActionListener{

        @Override
        public void actionPerformed(ActionEvent e) {
            
            Object source = e.getSource();
            if(source == save){
            String sql="Insert into logform(username,password)values(?,?)";
            try{
                pstm = con.prepareStatement(sql);
                pstm.setString(1, user1.getText());
                pstm.setString(2, pass1.getText());
                
                pstm.execute();
                JOptionPane.showMessageDialog(null, "Saved!");
            }catch(Exception se){
               JOptionPane.showMessageDialog(null, "Save Failed");
            }
            }
        }        
    }

      public void run(){ 
        
          setSize(500,300);
        setLocationRelativeTo(null);
        setVisible(true);
        setResizable(false);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
      
      
           public static void main(String[] args){
            
            RegistrationForm rf = new RegistrationForm();
            rf.run();
        }
}

我想将 MySQL 数据库中的数据显示到 JTextField。例如，MySQL 数据库中 UserID 的数据为 1，我想在 JTextField 中显示该数据，他们无法在 JTextField 中编辑文本。

谁能帮帮我？

Answer 1

如果用户 ID 是整数，则使用此代码

jTextField.setText(String.valueOf(UserID);
//This make jTextField not editable
jTextField.setEditable(false);