Java 当类中实际上有一个主方法时，没有主方法

有很多这样的问题，但我已经阅读了其中95%的大致XD 基本上我的代码有一个主类，但它说没有，发生了什么

public class RegisterGUI extends javax.swing.JFrame {

public RegisterGUI() {
    initComponents();
}

/**
 * This method is called from within the constructor to initialize the form.
 * WARNING: Do NOT modify this code. The content of this method is always
 * regenerated by the Form Editor.
 */
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">                          
private void initComponents() {

    PaySafeTitle = new javax.swing.JLabel();
    TitleLabel = new javax.swing.JLabel();
    FirstNameLabel = new javax.swing.JLabel();
    LastNameLabel = new javax.swing.JLabel();
    EmailAddLabel = new javax.swing.JLabel();
    UsernameLabel = new javax.swing.JLabel();
    PasswordLabel = new javax.swing.JLabel();
    ConfimationLabel = new javax.swing.JLabel();
    TitleList = new javax.swing.JComboBox();
    TitleField = new javax.swing.JTextField();
    FirstNameField = new javax.swing.JTextField();
    LastNameField = new javax.swing.JTextField();
    EmailAddField = new javax.swing.JTextField();
    UsernameField = new javax.swing.JTextField();
    PasswordField = new javax.swing.JPasswordField();
    ConfirmationField = new javax.swing.JPasswordField();
    PasswordMatchLabel = new javax.swing.JLabel();
    MatchResult = new javax.swing.JTextField();
    NextBtn = new javax.swing.JButton();

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
    getContentPane().setLayout(new org.netbeans.lib.awtextra.AbsoluteLayout());

    PaySafeTitle.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
    PaySafeTitle.setIcon(new javax.swing.ImageIcon(getClass().getResource("/PaySafeLogo.png"))); // NOI18N
    getContentPane().add(PaySafeTitle, new org.netbeans.lib.awtextra.AbsoluteConstraints(10, 11, 380, 37));

    TitleLabel.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
    TitleLabel.setText("Title:");
    getContentPane().add(TitleLabel, new org.netbeans.lib.awtextra.AbsoluteConstraints(10, 54, 98, 23));

    FirstNameLabel.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
    FirstNameLabel.setText("First name:");
    getContentPane().add(FirstNameLabel, new org.netbeans.lib.awtextra.AbsoluteConstraints(10, 83, 98, 23));

    LastNameLabel.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
    LastNameLabel.setText("Last name:");
    getContentPane().add(LastNameLabel, new org.netbeans.lib.awtextra.AbsoluteConstraints(10, 112, 98, 23));

    EmailAddLabel.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
    EmailAddLabel.setText("Email Address:");
    getContentPane().add(EmailAddLabel, new org.netbeans.lib.awtextra.AbsoluteConstraints(10, 141, 98, 23));

    UsernameLabel.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
    UsernameLabel.setText("Username:");
    getContentPane().add(UsernameLabel, new org.netbeans.lib.awtextra.AbsoluteConstraints(10, 170, 98, 23));

    PasswordLabel.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
    PasswordLabel.setText("Password:");
    getContentPane().add(PasswordLabel, new org.netbeans.lib.awtextra.AbsoluteConstraints(10, 199, 98, 23));

    ConfimationLabel.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
    ConfimationLabel.setText("Confirm Password:");
    getContentPane().add(ConfimationLabel, new org.netbeans.lib.awtextra.AbsoluteConstraints(10, 228, 98, 23));

    TitleList.setModel(new javax.swing.DefaultComboBoxModel(new String[] { "Mr", "Mrs", "Miss", "Ms", "Dr", "Other..." }));
    getContentPane().add(TitleList, new org.netbeans.lib.awtextra.AbsoluteConstraints(112, 55, 100, -1));

    TitleField.setEditable(false);
    getContentPane().add(TitleField, new org.netbeans.lib.awtextra.AbsoluteConstraints(218, 55, 172, -1));
    getContentPane().add(FirstNameField, new org.netbeans.lib.awtextra.AbsoluteConstraints(112, 84, 278, -1));
    getContentPane().add(LastNameField, new org.netbeans.lib.awtextra.AbsoluteConstraints(112, 113, 278, -1));
    getContentPane().add(EmailAddField, new org.netbeans.lib.awtextra.AbsoluteConstraints(112, 142, 278, -1));
    getContentPane().add(UsernameField, new org.netbeans.lib.awtextra.AbsoluteConstraints(112, 171, 278, -1));

    PasswordField.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            PasswordFieldActionPerformed(evt);
        }
    });
    getContentPane().add(PasswordField, new org.netbeans.lib.awtextra.AbsoluteConstraints(112, 200, 170, -1));
    getContentPane().add(ConfirmationField, new org.netbeans.lib.awtextra.AbsoluteConstraints(112, 229, 170, -1));

    PasswordMatchLabel.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
    PasswordMatchLabel.setText("Password match:");
    getContentPane().add(PasswordMatchLabel, new org.netbeans.lib.awtextra.AbsoluteConstraints(290, 200, 100, 20));

    MatchResult.setEditable(false);
    MatchResult.setHorizontalAlignment(javax.swing.JTextField.CENTER);
    getContentPane().add(MatchResult, new org.netbeans.lib.awtextra.AbsoluteConstraints(290, 230, 100, -1));
    do{
        if((PasswordField.getPassword())==(ConfirmationField.getPassword()));
        MatchResult.setText("MATCH");
    }
    else{
        MatchResult.setText("NO MATCH");
    }
    while((PasswordField.getPassword())!(ConfirmationField.getPassword()));

    NextBtn.setText("Next");
    getContentPane().add(NextBtn, new org.netbeans.lib.awtextra.AbsoluteConstraints(180, 260, -1, -1));

    pack();
}// </editor-fold>                        

private void PasswordFieldActionPerformed(java.awt.event.ActionEvent evt) {                                              
    // TODO add your handling code here:
}                                             

/**
 * @param args the command line arguments
 */
public static void main(String args[]) {
    /* Set the Nimbus look and feel */
    //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
    /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
     * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
     */
    try {
        for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
            if ("Nimbus".equals(info.getName())) {
                javax.swing.UIManager.setLookAndFeel(info.getClassName());
                break;
            }
        }
    } catch (ClassNotFoundException ex) {
        java.util.logging.Logger.getLogger(RegisterGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (InstantiationException ex) {
        java.util.logging.Logger.getLogger(RegisterGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (IllegalAccessException ex) {
        java.util.logging.Logger.getLogger(RegisterGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (javax.swing.UnsupportedLookAndFeelException ex) {
        java.util.logging.Logger.getLogger(RegisterGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    }
    //</editor-fold>

    /* Create and display the form */
    java.awt.EventQueue.invokeLater(new Runnable() {
        public void run() {
            new RegisterGUI().setVisible(true);
        }
    });
}
// Variables declaration - do not modify                     
private javax.swing.JLabel ConfimationLabel;
private javax.swing.JPasswordField ConfirmationField;
private javax.swing.JTextField EmailAddField;
private javax.swing.JLabel EmailAddLabel;
private javax.swing.JTextField FirstNameField;
private javax.swing.JLabel FirstNameLabel;
private javax.swing.JTextField LastNameField;
private javax.swing.JLabel LastNameLabel;
private javax.swing.JTextField MatchResult;
private javax.swing.JButton NextBtn;
private javax.swing.JPasswordField PasswordField;
private javax.swing.JLabel PasswordLabel;
private javax.swing.JLabel PasswordMatchLabel;
private javax.swing.JLabel PaySafeTitle;
private javax.swing.JTextField TitleField;
private javax.swing.JLabel TitleLabel;
private javax.swing.JComboBox TitleList;
private javax.swing.JTextField UsernameField;
private javax.swing.JLabel UsernameLabel;
// End of variables declaration                   
}

公共类注册表GUI扩展了javax.swing.JFrame{
公共注册表GUI（）{
初始化组件（）；
}
/**
*从构造函数中调用此方法来初始化表单。
*警告：不要修改此代码。此方法的内容始终为
*由表单编辑器重新生成。
*/
@抑制警告（“未选中”）
//                           
私有组件（）{
paysafetTitle=newjavax.swing.JLabel（）；
TitleLabel=newjavax.swing.JLabel（）；
FirstNameLabel=newjavax.swing.JLabel（）；
lastnamelab=newjavax.swing.JLabel（）；
EmailAddLabel=newjavax.swing.JLabel（）；
usernamelab=newjavax.swing.JLabel（）；
PasswordLabel=newjavax.swing.JLabel（）；
configmationlabel=newjavax.swing.JLabel（）；
TitleList=newjavax.swing.JComboBox（）；
TitleField=newjavax.swing.JTextField（）；
FirstNameField=newjavax.swing.JTextField（）；
LastNameField=newjavax.swing.JTextField（）；
EmailAddField=newjavax.swing.JTextField（）；
UsernameField=newjavax.swing.JTextField（）；
PasswordField=newjavax.swing.JPasswordField（）；
ConfirmationField=newjavax.swing.JPasswordField（）；
PasswordMatchLabel=newjavax.swing.JLabel（）；
MatchResult=newjavax.swing.JTextField（）；
NextBtn=newjavax.swing.JButton（）；
setDefaultCloseOperation（javax.swing.WindowConstants.EXIT_ON_CLOSE）；
getContentPane（）.setLayout（new org.netbeans.lib.awtextra.AbsoluteLayout（））；
setHorizontalAlignment（javax.swing.SwingConstants.CENTER）；
PaySafetTitle.setIcon（新的javax.swing.ImageIcon（getClass（）.getResource（“/PaySafeLogo.png”）；//NOI18N
getContentPane（）.add（PaySafetTitle，new org.netbeans.lib.awtextra.AbsoluteConstraints（10,11,380,37））；
TitleLabel.setHorizontalAlignment（javax.swing.SwingConstants.CENTER）；
TitleLabel.setText（“标题：”）；
getContentPane（）.add（TitleLabel，new org.netbeans.lib.awtextra.AbsoluteConstraints（10,54,98,23））；
setHorizontalAlignment（javax.swing.SwingConstants.CENTER）；
setText（“名字：”）；
getContentPane（）.add（FirstNameLabel，new org.netbeans.lib.awtextra.AbsoluteConstraints（10,83,98,23））；
setHorizontalAlignment（javax.swing.SwingConstants.CENTER）；
setText（“姓氏：”）；
getContentPane（）.add（LastNameLabel，new org.netbeans.lib.awtextra.AbsoluteConstraints（10112,98,23））；
EmailAddLabel.setHorizontalAlignment（javax.swing.SwingConstants.CENTER）；
EmailAddLabel.setText（“电子邮件地址：”）；
getContentPane（）.add（EmailAddLabel，new org.netbeans.lib.awtextra.AbsoluteConstraints（101419823））；
usernamelab.setHorizontalAlignment（javax.swing.SwingConstants.CENTER）；
usernamelab.setText（“用户名：”）；
getContentPane（）.add（usernamelab，new org.netbeans.lib.awtextra.AbsoluteConstraints（101709823））；
setHorizontalAlignment（javax.swing.SwingConstants.CENTER）；
PasswordLabel.setText（“密码：”）；
getContentPane（）.add（PasswordLabel，new org.netbeans.lib.awtextra.AbsoluteConstraints（1019998,23））；
ConfimationLabel.setHorizontalAlignment（javax.swing.SwingConstants.CENTER）；
ConfimationLabel.setText（“确认密码：”）；
getContentPane（）.add（conflicationLabel，new org.netbeans.lib.awtextra.AbsoluteConstraints（10228,98,23））；
TitleList.setModel（新的javax.swing.DefaultComboxModel（新字符串[]{“Mr”、“Mrs”、“Miss”、“Ms”、“Dr”、“Other…”））；
getContentPane（）.add（标题列表，new org.netbeans.lib.awtextra.AbsoluteConstraints（112,55,100，-1））；
TitleField.setEditable（假）；
getContentPane（）.add（TitleField，new org.netbeans.lib.awtextra.AbsoluteConstraints（218,55172，-1））；
getContentPane（）.add（FirstNameField，new org.netbeans.lib.awtextra.AbsoluteConstraints（11284278，-1））；
getContentPane（）.add（LastNameField，new org.netbeans.lib.awtextra.AbsoluteConstraints（112113278，-1））；
getContentPane（）.add（EmailAddField，new org.netbeans.lib.awtextra.AbsoluteConstraints（112142278，-1））；
getContentPane（）.add（UsernameField，new org.netbeans.lib.awtextra.AbsoluteConstraints（112171278，-1））；
PasswordField.addActionListener（新java.awt.event.ActionListener（）{
public void actionPerformed（java.awt.event.ActionEvent evt）{
PasswordFieldActionPerformed（evt）；
}
});
getContentPane（）.add（PasswordField，new org.netbeans.lib.awtextra.AbsoluteConstraints（112200170，-1））；
getContentPane（）.add（ConfirmationField，new org.netbeans.lib.awtextra.AbsoluteConstraints（112229170，-1））；
PasswordMatchLabel.setHorizontalAlignment（javax.swing.SwingConstants.CENTER）；
PasswordMatchLabel.setText（“密码匹配：”）；
getContentPane（）.add（PasswordMatchLabel，new org.netbeans.lib.awtextra.AbsoluteConstraints（290200100,20））；
MatchResult.setEditable（false）；
setHorizontalAlignment（javax.swing.JTextField.CENTER）；
getContentPane（）.add（MatchResult，new org.netbeans.lib.awtextra.AbsoluteConstraints（290230100，-1））；
做{
if（（PasswordField.getPassword（））==（ConfirmationField.getPassword（））；
MatchResult.setText（“匹配”）；
}
否则{
MatchResult.setText（“不匹配”）；
}
而（（PasswordField.getPassword（））！（ConfirmationField.getPassword（））；
NextBtn.setText（“下一步”）；
getContentPane（）.add（NextBtn，new org.netbeans.lib.awtextra.AbsoluteConstraints（180260，-1，-1））；
包装（）；
}//                         
private void PasswordFieldActionPerformed（java.awt.event.ActionEvent evt）{
//TODO在此处添加您的处理代码：
}                                             
/**
*@param指定命令行参数
*/
公共静态无效m
while((PasswordField.getPassword())!(ConfirmationField.getPassword()));

while((PasswordField.getPassword()) != (ConfirmationField.getPassword()));

do{
    if((PasswordField.getPassword())==(ConfirmationField.getPassword()));
    MatchResult.setText("MATCH");
}
else{
    MatchResult.setText("NO MATCH");
}
while((PasswordField.getPassword())!(ConfirmationField.getPassword()));

do {
    if (Arrays.equals(PasswordField.getPassword(), ConfirmationField.getPassword()))
        MatchResult.setText("MATCH");
    else {
        MatchResult.setText("NO MATCH");
    }
}
while(!Arrays.equals(PasswordField.getPassword(), ConfirmationField.getPassword()));