检测按钮中的输入键

Question

package test;
import java.awt.*;
import javax.swing.*;

import java.awt.event.*;
public class swing_sample extends JFrame
{
    //declaring our swing components
    JLabel l_name,l_pass;
    JFrame e;
    JTextField t_name;
    JPasswordField t_pass;     //A special JTextField but hides input text
    JButton button;
    Container c;

    //a inner class to handling ActionEvents
  public  handler2 handle;

    //a separate class for processing database connection and authentication
    database db;
    private JLabel lblNewLabel;

    swing_sample()
    {
        super("Login form");

        c=getContentPane();

        //extra classes
        db=new database();
            handle =new handler2();

                //swing components
        l_name=new JLabel("Username");
        l_name.setBounds(189, 69, 153, 45);
        l_pass=new JLabel("Password");
        l_pass.setBounds(189, 151, 126, 36);
        t_name=new JTextField(10);
        t_name.setBounds(321, 75, 126, 33);
        t_pass=new JPasswordField(10);
        t_pass.setBounds(321, 147, 126, 40);
        button=new JButton("Login");
        Image img50=new ImageIcon(this.getClass().getResource("/aaaa.png")).getImage();
        button.setIcon(new ImageIcon(img50));
        button.setBounds(262, 239, 137, 53);

        //adding actionlistener to the button
        button.addActionListener(handle);
        getContentPane().setLayout(null);

        //add to contaienr
        c.add(l_name);
        c.add(t_name);
        c.add(l_pass);
        c.add(t_pass);
        c.add(button);

        lblNewLabel = new JLabel("");
        Image img40=new ImageIcon(this.getClass().getResource("/aaaaa.png")).getImage();
        lblNewLabel.setIcon(new ImageIcon(img40));
        lblNewLabel.setBounds(10, 75, 169, 137);
        getContentPane().add(lblNewLabel);
        //visual
        setVisible(true);
        setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        setSize(631,412);

    }
    public static void main(String args[])
    {
        swing_sample sample=new swing_sample();
    }

    //an inner class .You can also write as a separate class
    class handler2 implements ActionListener
    {
        //must implement method
        //This is triggered whenever the user clicks the login button
        public void actionPerformed(ActionEvent ae)
        {
            //checks if the button clicked
            if(ae.getSource()==button)
            {
                char[] temp_pwd=t_pass.getPassword();
                String pwd=null;
                pwd=String.copyValueOf(temp_pwd);
                System.out.println("Username,Pwd:"+t_name.getText()+","+pwd);

                //The entered username and password are sent via "checkLogin()" which return boolean
                if(db.checkLogin(t_name.getText(), pwd))
                {
                    //a pop-up box
                    JOptionPane.showMessageDialog(null, "You have logged in successfully","Success",
                                        JOptionPane.INFORMATION_MESSAGE);
                }
                else
                {
                    //a pop-up box
                    JOptionPane.showMessageDialog(null, "Login failed!","Failed!!",
                                        JOptionPane.ERROR_MESSAGE);
                }
            }//if
        }//method

    }//inner class
}//class

这是我忘记密码的Java应用程序，它还有一个主要工作的数据库类，只想问一下如何使按钮识别输入键输入，一旦识别，它就会执行动作块。