JAVA GUI程序交互 示例_java gui 怎么调用后端

import java.awt.EventQueue;
import java.awt.GridLayout;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
 
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.border.EmptyBorder;
 
 
public class EventDemo extends JFrame{
	
	/**
	 * 
	 */
	private static final long serialVersionUID = 8162801603108721756L;
 
	private JPanel contentPane;
	
	private JTextField textField1;
	private JTextField textField2;
	
	private JLabel label1;
	private JLabel label2;
	
 
	public static void main(String[] args){
		try {
			UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");// 设置程序外观的风格
		} catch (Throwable e) {
			// TODO: handle exception
			e.printStackTrace();
		}
		
		EventQueue.invokeLater(new Runnable(){
 
			@Override
			public void run() {
				// TODO Auto-generated method stub
				try {
					EventDemo frame = new EventDemo();// 设置窗体
					frame.setVisible(true);// 设置可见
				} catch (Exception e) {
					// TODO: handle exception
					e.printStackTrace();
				}
			}			
		});			
	}
	
	public EventDemo(){
		setTitle("监听文本输入事件");
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setBounds(100, 100, 250, 100);
		
		contentPane = new JPanel();// 创建全局内容面板
		contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));// 设置边框大小
		
		setContentPane(contentPane);// 应用全局内容面板
		
		contentPane.setLayout(new GridLayout(2,1,5,5));// 为内容面板使用网格布局
		
		JPanel pannel1 = new JPanel();// 新建面板来组织标签
		contentPane.add(pannel1);// 添加一号内容面板
		label1 = new JLabel("第一个文本框");// 一号面板标签
		pannel1.add(label1);
		textField1 = new JTextField();// 一号内容面板文本框
		
		// 一号 文本框添加按键释放事件监听
		textField1.addKeyListener(new KeyAdapter() {
			@Override
			public void keyReleased(KeyEvent e){
				do_textField1_keyRelease(e);
			}
		});
		pannel1.add(textField1);// 应用文本框
		textField1.setColumns(18);// 将文本框设置成18列
		
		JPanel panel2 = new JPanel();
		contentPane.add(panel2);
		label2 = new JLabel("第二个文本框");
		panel2.add(label2);
		textField2 = new JTextField();
		panel2.add(textField2);
		textField2.setColumns(18);
		
	}
 
	protected void do_textField1_keyRelease(KeyEvent e) {
		// TODO Auto-generated method stub
		String text = textField1.getText();// 获得第一个文本框的文本内容
		textField2.setText(text);// 将获取的文本内容显示在第二个文本框内
	}
 
	
 
}