Eclipse：JAVAW 终止

Question

也许我误点击了某些东西，我的 Java 应用程序将无法运行。 我制作了以下Login Form并按f12运行我的 java 应用程序。

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显示以下错误

我不知道发生了什么，因为在过去的几个小时里一切都很好。 我相信我在我的日食中误点击了某些东西或激活了某些东西而犯了一些错误。

为什么我的登录表单没有显示？

idk 下图是否与我的登录表单问题有关

解决了，问题来自以下代码

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

    }

}

我仍然不明白为什么错误来自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。 如果您进行了一些更改，请查看您当地的历史记录。

Answer 2

更改您的 main() 调用 Cl_Login 构造函数，如下所示：

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