Eclipse：JAVAW 終止

Question

也許我誤點擊了某些東西，我的 Java 應用程序將無法運行。 我制作了以下Login Form並按f12運行我的 java 應用程序。

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

import javax.swing.*;


public class Cl_Login extends JFrame {

    Cl_Register registerform = new Cl_Register();
    Command cmd = new Command();
    Validate val = new Validate();
    public static Cl_Login logform = null;
    static private String form_name = "Gamestops Login";
    static private String lbl_judul = "GameStops";
    static private String lbl_username = "Username";
    static private String lbl_password = "Password";
    static private String lbl_buttonlogin = "Login";
    static private String lbl_buttonreset = "Reset";
    static private String lbl_buttonregister = "Register";          

    public void addComponentsToPane(Container pane) {                       
        JButton buttonlogin,buttonregister,buttonreset; 
        JLabel labelatas,labelbawah,labelusername,labelpassword;
        JPanel panelbawah,paneltengah,panelkiri,panelkanan;
        final JTextField textusername;
        final JPasswordField textpassword;

        labelatas = new JLabel(lbl_judul,SwingConstants.CENTER);        
        pane.add(labelatas, BorderLayout.PAGE_START);


        paneltengah= new JPanel(new GridLayout(2,2));

        labelusername = new JLabel(lbl_username,SwingConstants.CENTER);                                                         
        paneltengah.add(labelusername);

        labelpassword = new JLabel(lbl_password,SwingConstants.CENTER);
        paneltengah.add(labelpassword);

        textusername = new JTextField(20);
        textpassword = new JPasswordField(20);
        paneltengah.add(textusername);
        paneltengah.add(textpassword);
        pane.add(paneltengah, BorderLayout.LINE_START);         

        panelbawah = new JPanel(new FlowLayout(FlowLayout.CENTER)); 
        buttonlogin = new JButton(new AbstractAction(lbl_buttonlogin) {

            @Override
            public void actionPerformed(ActionEvent e) {

                String inusernamenya = textusername.getText();
                String inpassword = textpassword.getText();

                if(val.isEmpty(inusernamenya) || val.isEmpty(inpassword))
                {
                    cmd.printError("Username or Password must be filled !", form_name);
                }
                else
                {
                    cmd.printSuccess("Login Success !", form_name);
                    Cl_Main mainform = new Cl_Main();
                    mainform.showFormAdmin(true);
//                  cmd.printSuccess(System.getProperty("sun.arch.data.model"), form_name);
//                  ConnectAccess ca = new ConnectAccess();
//                  ResultSet resultnya = ca.getData("Select * from MsUser where Username = '"+inusernamenya+"' and password = '"+inpassword+"'");
//                  try {
//                      if(resultnya.next())
//                      {
//                          
//                          cmd.printSuccess(inusernamenya+" dan "+inpassword+" berhasil login", form_name);                            
//                          Cl_Main mainform = new Cl_Main();                           
//                      }
//                      else
//                      {
//                          cmd.printError("Invalid username or password !", form_name);
//                      }
//                  } catch (SQLException e) {
//                      // TODO Auto-generated catch block
//                      e.printStackTrace();
//                  }

                    //if user role admin blabla user blabla             
                    //show MDI

                }
            }
        });         
        buttonreset = new JButton(lbl_buttonreset);
        buttonreset.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent arg0) { 
                textusername.setText("");
                textpassword.setText("");
            }
        });
        buttonregister = new JButton(lbl_buttonregister);       
                buttonregister.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent arg0) {
                // TODO Auto-generated method stub
//              new Cl_Register().setVisible(true);
                registerform.showRegister();
                setVisible(false);
            }
        });
        panelbawah.add(buttonlogin);
        panelbawah.add(buttonreset);        
        panelbawah.add(buttonregister);
        pane.add(panelbawah, BorderLayout.PAGE_END);

    }   

    public Cl_Login() {
        setVisible(true);       
        this.setTitle(form_name);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setResizable(false);        
        addComponentsToPane(this.getContentPane());
        pack();
        setLocationRelativeTo(null);

    }

    /**
     * @param args
     */
    public static void main(String[] args) {        
        Cl_Login login = new Cl_Login();
    }

}

然后，eclipse顯示以下錯誤

我不知道發生了什么，因為在過去的幾個小時里一切都很好。 我相信我在我的日食中誤點擊了某些東西或激活了某些東西而犯了一些錯誤。

為什么我的登錄表單沒有顯示？

idk 下圖是否與我的登錄表單問題有關

解決了，問題來自以下代碼

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.*;


public class Cl_Register{

//  Cl_Login loginform = new Cl_Login(); << done by markin as comment, still not understand why does this line causing the problem
    Command cmd = new Command();
    Validate val = new Validate();
    static private String form_name = "Register Form";
    static private String lbl_judul = "Register";
    static private String lbl_name = "Name";
    static private String lbl_username = "Username";
    static private String lbl_password = "Password";
    static private String lbl_gender = "Gender";
    static private String lbl_email = "Email";
    static private String lbl_hobby = "Hobby";
    static private String lbl_role = "Role";
    static private String lbl_buttonlogin = "Login";
    static private String lbl_buttonreset = "Reset";
    static private String lbl_buttonregister = "Register";  




    public void showRegister() {        

        JFrame frame = new JFrame(form_name);
        JButton buttonlogin,buttonregister,buttonreset; 
        JLabel labelatas,labeljudul,labelname,labelusername,labelpassword,labelgender,labelemail,labelhobby,labelrole;
        JPanel panelbawah,paneltengah,panelkiri,panelkanan,panelgender;
        final JTextField textname,textusername,textemail;
        final JPasswordField textpassword;
        JRadioButton radiobuttonmale,radiobuttonfemale;
        JComboBox comboboxhobby,comboboxrole;

        String[]listhobby = {"Coding", "Swimming", "Racing", "Playing Football", "Playing Basketball", "Painting", "Drawing"};
        String[]listrole={"Admin","User"};
        labelatas = new JLabel(lbl_judul,SwingConstants.CENTER);

        frame.add(labelatas,BorderLayout.PAGE_START);

        panelkiri = new JPanel(new GridLayout(7,1));        
        labelname = new JLabel(lbl_name,SwingConstants.LEFT);       
        labelusername = new JLabel(lbl_username,SwingConstants.LEFT);                                                                           
        labelpassword = new JLabel(lbl_password,SwingConstants.LEFT);               
        labelgender = new JLabel(lbl_gender,SwingConstants.LEFT);               
        labelemail = new JLabel(lbl_email,SwingConstants.LEFT);         
        labelhobby = new JLabel(lbl_hobby,SwingConstants.LEFT);             
        labelrole = new JLabel(lbl_role,SwingConstants.LEFT);               
        panelkiri.add(labelname);
        panelkiri.add(labelusername);
        panelkiri.add(labelpassword);       
        panelkiri.add(labelemail);  
        panelkiri.add(labelgender);
        panelkiri.add(labelhobby);
        panelkiri.add(labelrole);
        frame.add(panelkiri, BorderLayout.LINE_START);  

        panelkanan = new JPanel(new GridLayout(7,1));   
        panelgender = new JPanel(new FlowLayout(FlowLayout.CENTER));
        textname = new JTextField(5);       
        textusername = new JTextField(20);
        textpassword = new JPasswordField(20);
        textemail = new JTextField(20);
        comboboxhobby = new JComboBox(listhobby);
        comboboxrole = new JComboBox(listrole);


        radiobuttonmale = new JRadioButton("Male");
        radiobuttonfemale = new JRadioButton("Female");
        panelgender.add(radiobuttonmale);
        panelgender.add(radiobuttonfemale);

        comboboxhobby.setSelectedIndex(0);
        comboboxrole.setSelectedIndex(0);
        radiobuttonmale.setSelected(true);


        panelkanan.add(textname);       
        panelkanan.add(textusername);
        panelkanan.add(textpassword);
        panelkanan.add(textemail);
        panelkanan.add(panelgender);        
        panelkanan.add(comboboxhobby);
        panelkanan.add(comboboxrole);

        frame.add(panelkanan, BorderLayout.LINE_END);
        panelbawah = new JPanel(new FlowLayout(FlowLayout.CENTER)); 
        buttonlogin = new JButton(lbl_buttonlogin);     
        buttonlogin.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent arg0) {         

            }
        });
        buttonreset = new JButton(lbl_buttonreset);
        buttonreset.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent arg0) {
                textname.setText("");
                textusername.setText("");
                textpassword.setText("");
                textemail.setText("");
            }
        });
        buttonregister = new JButton(lbl_buttonregister);
        buttonregister.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent arg0) {
                // TODO Auto-generated method stub


            }
        });
        panelbawah.add(buttonlogin);
        panelbawah.add(buttonreset);        
        panelbawah.add(buttonregister);
        frame.add(panelbawah, BorderLayout.PAGE_END);
        frame.pack();
        frame.setVisible(true);     
        frame.setDefaultCloseOperation(frame.EXIT_ON_CLOSE);
        frame.setResizable(false);                      
        frame.setLocationRelativeTo(null);

    }   


    public Cl_Register() {              

    }

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub                  
    }

    public void actionPerformed(ActionEvent arg0) {
        // TODO Auto-generated method stub

    }

}

我仍然不明白為什么錯誤來自Cl_Register

Answer 1

正如 gamliela 所指出的，你的 main 是空的。不可能是它更早地工作。 如果您進行了一些更改，請查看您當地的歷史記錄。

Answer 2

更改您的 main() 調用 Cl_Login 構造函數，如下所示：

public static void main(String[] args) {
    Cl_Login login = new Cl_Login();       
}