无法创建JAR文件 - 未找到主方法

Question

我正在尝试创建给定类的JAR。

我正在使用一个名为JARBuilder的工具，因为Eclipse在创建JAR文件方面毫无帮助。

当我尝试创建JAR时，它表示可以找到main方法，尽管主要方法已明确定义。

有人可以提出建议吗？

import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.io.IOException;
import java.net.UnknownHostException;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.EmptyBorder;

public class Login extends JFrame {

private JPanel contentPane;
private JTextField textField_1;
private JTextField textField_2;
private String name;
private String address;
private int port;
private JTextField textField;

    public Login() {

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 400, 348);
        setLocationRelativeTo(null);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);
        contentPane.setLayout(null);

        JLabel lblUsername = new JLabel("Username");
        lblUsername.setBounds(158, 44, 72, 16);
        contentPane.add(lblUsername);

        textField_1 = new JTextField();
        textField_1.setEditable(false);

        textField_1.setBounds(135, 111, 116, 22);
        contentPane.add(textField_1);
        textField_1.setColumns(10);

        JLabel lblServerIp = new JLabel("Server IP");
        lblServerIp.setBounds(158, 96, 56, 16);
        contentPane.add(lblServerIp);

        textField_2 = new JTextField();
        textField_2.setEditable(false);
        textField_1.setText("122.15.200.115");

        textField_2.addKeyListener(new KeyAdapter() {

             public void keyPressed(KeyEvent key) {

             }
        });

        textField_2.setBounds(135, 162, 116, 22);
        textField_2.setText("8000");
        contentPane.add(textField_2);
        textField_2.setColumns(10);

        JLabel lblPort = new JLabel("Port");
        lblPort.setBounds(174, 146, 56, 16);
        contentPane.add(lblPort);

        JButton btnLogin = new JButton("Login");
        btnLogin.addKeyListener(new KeyAdapter() {
            @Override
            public void keyPressed(KeyEvent arg0) {
                newWindow();
            }
        });

        btnLogin.addMouseListener(new MouseAdapter() {
             @Override
             public void mouseClicked(MouseEvent e) {
                 newWindow();
            }
        });

        btnLogin.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
            }
        }); 

        btnLogin.setBounds(145, 197, 97, 43);
        contentPane.add(btnLogin);

        textField = new JTextField();
        textField.addKeyListener(new KeyAdapter() {

            public void keyPressed(KeyEvent key) {

                if(key.getKeyCode()==KeyEvent.VK_ENTER)
                {

                      if(!(textField.getText().equals("")))
                      {
                           name=textField.getText();
                           address=textField_1.getText();
                           port=Integer.parseInt(textField_2.getText());

                           try {
                                Chat_window window=new Chat_window(name, address, port);
                                dispose();
                           } catch (UnknownHostException e) {
                                // TODO Auto-generated catch block
                                e.printStackTrace();
                           } catch (IOException e) {
                                // TODO Auto-generated catch block
                                e.printStackTrace();
                           }
                       }
                 }
             }
        });

        textField.setColumns(10);
        textField.setBounds(135, 60, 116, 22);
        contentPane.add(textField);

        JLabel lblAuthorprashantPandey = new JLabel("Author:Prashant Pandey");
        lblAuthorprashantPandey.setBounds(125, 253, 186, 16);
        contentPane.add(lblAuthorprashantPandey);

    }

    public void newWindow(){

         name=textField.getText();
         address=textField_1.getText();
         port=Integer.parseInt(textField_2.getText());

         try {
             Chat_window window=new Chat_window(name, address, port);
         } catch (UnknownHostException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
         }
         dispose();
     }

    public static void main(String args[]) {

        EventQueue.invokeLater(new Runnable() {

             public void run() {
                 try {
                     Login frame = new Login();
                     frame.setVisible(true);
                 } catch (Exception e) {
                     e.printStackTrace();
                 }
             }
        });
    }
}