Jframe多次显示（Java Netbeans）

Question

哦，嘿，我是Java新手，我想通过单击“ SelectTimeAndDate”页面上的“确认”按钮，使我的程序从“ SelectTimeAndDate”页面显示一个名为“ NewCode”的新页面。 但是NewCode页面保持连续显示多次而不是一次。

这是我的SelectTimeAndDate的代码：

package car.park.auto.pay.system;
import java.io.*;
import java.lang.*;
import java.util.*;
import javax.swing.JOptionPane;
import javax.swing.JTextField;

public class SelectTimeAndDate extends javax.swing.JFrame {
private JTextField hour;
private JTextField minute;
private JTextField second;
private JTextField date;
private JTextField month;
private JTextField year; 

public SelectTimeAndDate() {
    initComponents();


}

@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">                          
private void initComponents() {

    jPanel1 = new javax.swing.JPanel();
    jLabel1 = new javax.swing.JLabel();
    jLabel2 = new javax.swing.JLabel();
    jLabel3 = new javax.swing.JLabel();
    confirmBut = new javax.swing.JButton();
    cancelBut1 = new javax.swing.JButton();
    hourField = new javax.swing.JTextField();
    dateField = new javax.swing.JTextField();
    minuteField = new javax.swing.JTextField();
    jLabel4 = new javax.swing.JLabel();
    jLabel5 = new javax.swing.JLabel();
    jLabel6 = new javax.swing.JLabel();
    jLabel7 = new javax.swing.JLabel();
    monthField = new javax.swing.JTextField();
    secondField = new javax.swing.JLabel();
    hour2 = new javax.swing.JTextField();
    hour5 = new javax.swing.JTextField();
    yearField = new javax.swing.JLabel();

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
    setTitle("Roy's Car Parking Auto Pay Station System");

    jLabel1.setText("Please input time and date that you are entering:");

    jLabel2.setText("Input time (hh:mm:ss):");
    jLabel2.setCursor(new java.awt.Cursor(java.awt.Cursor.DEFAULT_CURSOR));

    jLabel3.setText("Input date (dd/mm/yy):");

    confirmBut.setText("Confirm");
    confirmBut.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            confirmButActionPerformed(evt);
        }
    });

    cancelBut1.setText("Cancel");
    cancelBut1.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            cancelBut1ActionPerformed(evt);
        }
    });

    hourField.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            hourFieldActionPerformed(evt);
        }
    });

    jLabel4.setText("Hour:");

    jLabel5.setText("Date:");

    jLabel6.setText("Minute:");

    jLabel7.setText("Month:");

    secondField.setText("Second:");

    yearField.setText("Year:");

    javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
    jPanel1.setLayout(jPanel1Layout);
    jPanel1Layout.setHorizontalGroup(
        jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(jPanel1Layout.createSequentialGroup()
            .addGap(87, 87, 87)
            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(jPanel1Layout.createSequentialGroup()
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                        .addComponent(jLabel2, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                        .addComponent(jLabel3, javax.swing.GroupLayout.DEFAULT_SIZE, 128, Short.MAX_VALUE))
                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                        .addGroup(jPanel1Layout.createSequentialGroup()
                            .addComponent(jLabel5)
                            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                            .addComponent(dateField))
                        .addGroup(jPanel1Layout.createSequentialGroup()
                            .addComponent(jLabel4)
                            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                            .addComponent(hourField, javax.swing.GroupLayout.PREFERRED_SIZE, 34, javax.swing.GroupLayout.PREFERRED_SIZE))))
                .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
                    .addComponent(confirmBut, javax.swing.GroupLayout.PREFERRED_SIZE, 103, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addGap(22, 22, 22)))
            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(jPanel1Layout.createSequentialGroup()
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                        .addGroup(jPanel1Layout.createSequentialGroup()
                            .addComponent(jLabel6)
                            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                            .addComponent(minuteField, javax.swing.GroupLayout.PREFERRED_SIZE, 37, javax.swing.GroupLayout.PREFERRED_SIZE))
                        .addGroup(jPanel1Layout.createSequentialGroup()
                            .addComponent(jLabel7)
                            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                            .addComponent(monthField)))
                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                        .addGroup(jPanel1Layout.createSequentialGroup()
                            .addComponent(secondField)
                            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                            .addComponent(hour2, javax.swing.GroupLayout.PREFERRED_SIZE, 37, javax.swing.GroupLayout.PREFERRED_SIZE))
                        .addGroup(jPanel1Layout.createSequentialGroup()
                            .addGap(14, 14, 14)
                            .addComponent(yearField)
                            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                            .addComponent(hour5, javax.swing.GroupLayout.PREFERRED_SIZE, 39, javax.swing.GroupLayout.PREFERRED_SIZE))))
                .addGroup(jPanel1Layout.createSequentialGroup()
                    .addGap(13, 13, 13)
                    .addComponent(cancelBut1, javax.swing.GroupLayout.PREFERRED_SIZE, 103, javax.swing.GroupLayout.PREFERRED_SIZE)))
            .addContainerGap(56, Short.MAX_VALUE))
        .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
            .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
            .addComponent(jLabel1)
            .addGap(121, 121, 121))
    );
    jPanel1Layout.setVerticalGroup(
        jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
            .addContainerGap(35, Short.MAX_VALUE)
            .addComponent(jLabel1)
            .addGap(18, 18, 18)
            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(jPanel1Layout.createSequentialGroup()
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                        .addComponent(jLabel2)
                        .addComponent(hourField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addComponent(minuteField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addComponent(jLabel4)
                        .addComponent(jLabel6))
                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                        .addComponent(jLabel3)
                        .addComponent(dateField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addComponent(jLabel5)
                        .addComponent(monthField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addComponent(jLabel7)))
                .addGroup(jPanel1Layout.createSequentialGroup()
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                        .addComponent(hour2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addComponent(secondField))
                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                        .addComponent(hour5, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addComponent(yearField))))
            .addGap(18, 18, 18)
            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addComponent(confirmBut, javax.swing.GroupLayout.PREFERRED_SIZE, 37, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addComponent(cancelBut1, javax.swing.GroupLayout.PREFERRED_SIZE, 37, javax.swing.GroupLayout.PREFERRED_SIZE))
            .addGap(28, 28, 28))
    );

    javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
    getContentPane().setLayout(layout);
    layout.setHorizontalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
            .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
            .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addGap(40, 40, 40))
    );
    layout.setVerticalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addGap(35, 35, 35)
            .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addContainerGap(69, Short.MAX_VALUE))
    );

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

private void hourFieldActionPerformed(java.awt.event.ActionEvent evt) {                                          

}                                         

private void cancelBut1ActionPerformed(java.awt.event.ActionEvent evt) {                                           
    new Menu().setVisible(true);
    this.dispose();// TODO add your handling code here:
}                                          

private void confirmButActionPerformed(java.awt.event.ActionEvent evt) {                                           
    String hour=hourField.getText();
    String minute=minuteField.getText();
    String second=secondField.getText();
    String date=dateField.getText();
    String month=monthField.getText();
    String year=yearField.getText();

    if(hour.isEmpty()||minute.isEmpty()||second.isEmpty()||date.isEmpty()||month.isEmpty()||year.isEmpty()){
        JOptionPane.showMessageDialog(this,String.format("Please input all the details!", JOptionPane.ERROR_MESSAGE));
    }else{
        NewCode.getObj().setVisible(true);
        this.dispose();

    }

}                                          




// Variables declaration - do not modify                     
private javax.swing.JButton cancelBut1;
private javax.swing.JButton confirmBut;
private javax.swing.JTextField dateField;
private javax.swing.JTextField hour2;
private javax.swing.JTextField hour5;
private javax.swing.JTextField hourField;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JLabel jLabel4;
private javax.swing.JLabel jLabel5;
private javax.swing.JLabel jLabel6;
private javax.swing.JLabel jLabel7;
private javax.swing.JPanel jPanel1;
private javax.swing.JTextField minuteField;
private javax.swing.JTextField monthField;
private javax.swing.JLabel secondField;
private javax.swing.JLabel yearField;
// End of variables declaration                   
}

这是我的NewCode的代码

package car.park.auto.pay.system;


public class NewCode extends javax.swing.JFrame {
private static NewCode obj = null;
static int SetVisible() {
    throw new UnsupportedOperationException("Not supported yet."); 
}
   public NewCode() {
    initComponents();

    java.awt.EventQueue.invokeLater(() -> {
        new NewCode().setVisible(true);
    });


   }
   public static NewCode getObj(){
   if(obj==null){
       obj=new NewCode();}
   return obj;
   }
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">                          
private void initComponents() {

    jLabel3 = new javax.swing.JLabel();
    jLabel4 = new javax.swing.JLabel();
    jButton2 = new javax.swing.JButton();

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

    jLabel3.setText("Please NOTE DOWN THIS CODE as when you are LEAVING you are REQUIRE to enter this code to complete the payment.");

    jLabel4.setText("Code generated:");

    jButton2.setText("Finish");

    javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
    getContentPane().setLayout(layout);
    layout.setHorizontalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(layout.createSequentialGroup()
                    .addGap(262, 262, 262)
                    .addComponent(jButton2, javax.swing.GroupLayout.PREFERRED_SIZE, 98, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGroup(layout.createSequentialGroup()
                    .addGap(31, 31, 31)
                    .addComponent(jLabel3))
                .addGroup(layout.createSequentialGroup()
                    .addGap(234, 234, 234)
                    .addComponent(jLabel4)))
            .addContainerGap(24, Short.MAX_VALUE))
    );
    layout.setVerticalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addGap(54, 54, 54)
            .addComponent(jLabel3)
            .addGap(43, 43, 43)
            .addComponent(jLabel4)
            .addGap(33, 33, 33)
            .addComponent(jButton2, javax.swing.GroupLayout.PREFERRED_SIZE, 41, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addContainerGap(64, Short.MAX_VALUE))
    );

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


// Variables declaration - do not modify                     
private javax.swing.JButton jButton2;
private javax.swing.JLabel jLabel3;
private javax.swing.JLabel jLabel4;
// End of variables declaration                   


}

请帮助我发现问题，谢谢！

编辑：我已经发现问题了！ 我已经通过设置更正了它

 new NewCode().setVisible(true);

至

 new NewCode().setVisible(false);

Answer 1

看你的构造函数

 public NewCode() {
    initComponents();

    java.awt.EventQueue.invokeLater(() -> {
        new NewCode().setVisible(true);
    });
 }

每次创建新的NewCode对象时，都会创建一个新的NewCode对象，以无穷循环结束。 为什么不简单地像这样构造构造函数呢？

public NewCode() {
    initComponents();
    this.setVisible(true);
}

另外，为什么还要在每个swing类的前面写完整的包名称？ 一次导入就不会容易了吗？