所以我跟着一个在youtube上制作杂货收银机的视频。我小心翼翼地一步一步地跟着它。但当谈到getText进入jTable1行时，就像，当我按下jButton1时，它不会像视频所示那样起作用。
所以，我把这个脚本复制到我的项目中，绝望地看它是否有效，但它没有。然后，当我在原始项目的原始文件上尝试它。有用。所以试着复制所有这些。完整到我的项目。编码，变量，已声明的按钮或用英语调用的按钮没有区别。 仍然不起作用。
/*
* To change this license header, choose License Headers in Project
Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package kasiraldo;
import static java.awt.event.KeyEvent.VK_BACK_SPACE;
import java.util.Vector;
import javax.swing.table.DefaultTableModel;
//import javax.swing.JTable;
/**
*
* @author AldoFerino
*/
public class kasirJframe extends javax.swing.JFrame {
/**
* Creates new form kasirJframe
*/
public kasirJframe() {
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() {
jPanel1 = new javax.swing.JPanel();
jLabel1 = new javax.swing.JLabel();
Nama = new javax.swing.JTextField();
jLabel2 = new javax.swing.JLabel();
Harga = new javax.swing.JTextField();
jLabel3 = new javax.swing.JLabel();
Qty = new javax.swing.JTextField();
jButton1 = new javax.swing.JButton();
Jumlah = new javax.swing.JLabel();
jScrollPane2 = new javax.swing.JScrollPane();
jTable1 = new javax.swing.JTable();
Pesan = new javax.swing.JLabel();
Totalharga = new javax.swing.JLabel();
Bayar = new javax.swing.JTextField();
jButton3 = new javax.swing.JButton();
Kembalian = new javax.swing.JLabel();
jButton2 = new javax.swing.JButton();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jLabel1.setText("Nama");
Nama.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
NamaActionPerformed(evt);
}
});
jLabel2.setText("Harga");
Harga.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
HargaActionPerformed(evt);
}
});
Harga.addKeyListener(new java.awt.event.KeyAdapter() {
public void keyPressed(java.awt.event.KeyEvent evt) {
HargaKeyPressed(evt);
}
public void keyTyped(java.awt.event.KeyEvent evt) {
HargaKeyTyped(evt);
}
});
jLabel3.setText("Qty");
Qty.setText(" ");
Qty.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
QtyActionPerformed(evt);
}
});
Qty.addKeyListener(new java.awt.event.KeyAdapter() {
public void keyPressed(java.awt.event.KeyEvent evt) {
QtyKeyPressed(evt);
}
public void keyTyped(java.awt.event.KeyEvent evt) {
QtyKeyTyped(evt);
}
});
jButton1.setText("Input");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
Jumlah.setText("0");
jTable1.setBorder(javax.swing.BorderFactory.createEtchedBorder());
jTable1.setModel(new javax.swing.table.DefaultTableModel(
new Object [][] {
},
new String [] {
"Nama", "Harga", "Qty", "Jumlah"
}
) {
boolean[] canEdit = new boolean [] {
false, false, false, false
};
public boolean isCellEditable(int rowIndex, int columnIndex) {
return canEdit [columnIndex];
}
});
jTable1.setAutoscrolls(false);
jTable1.setColumnSelectionAllowed(true);
jTable1.setOpaque(false);
jScrollPane2.setViewportView(jTable1);
jTable1.getColumnModel().getSelectionModel().setSelectionMode(javax.swing.ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
Pesan.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
Totalharga.setText("Rp.");
Bayar.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
BayarActionPerformed(evt);
}
});
Bayar.addKeyListener(new java.awt.event.KeyAdapter() {
public void keyPressed(java.awt.event.KeyEvent evt) {
BayarKeyPressed(evt);
}
public void keyTyped(java.awt.event.KeyEvent evt) {
BayarKeyTyped(evt);
}
});
jButton3.setText("Bayar");
jButton3.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton3ActionPerformed(evt);
}
});
Kembalian.setText("Rp.");
jButton2.setText("Delete");
jButton2.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton2ActionPerformed(evt);
}
});
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(61, 61, 61)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false)
.addComponent(jLabel3, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jLabel2, javax.swing.GroupLayout.Alignment.LEADING))
.addComponent(jLabel1))
.addGap(18, 18, 18)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false)
.addComponent(Nama)
.addComponent(Harga, javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(Qty, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.PREFERRED_SIZE, 151, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(18, 18, 18)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addGroup(jPanel1Layout.createSequentialGroup()
.addComponent(jButton1)
.addGap(28, 28, 28)
.addComponent(jButton2))
.addComponent(Jumlah, javax.swing.GroupLayout.PREFERRED_SIZE, 150, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addComponent(jScrollPane2, javax.swing.GroupLayout.PREFERRED_SIZE, 375, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false)
.addComponent(Kembalian, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jButton3, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(Bayar, javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(Totalharga, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.PREFERRED_SIZE, 375, javax.swing.GroupLayout.PREFERRED_SIZE))
.addComponent(Pesan, javax.swing.GroupLayout.PREFERRED_SIZE, 365, javax.swing.GroupLayout.PREFERRED_SIZE))
.addContainerGap(30, Short.MAX_VALUE))
);
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addContainerGap()
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addGroup(jPanel1Layout.createSequentialGroup()
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel1)
.addComponent(Nama, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(10, 10, 10)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel2)
.addComponent(Harga, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addComponent(Jumlah, javax.swing.GroupLayout.PREFERRED_SIZE, 50, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(18, 18, 18)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel3)
.addComponent(Qty, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jButton1)
.addComponent(jButton2))
.addGap(27, 27, 27)
.addComponent(Pesan, javax.swing.GroupLayout.PREFERRED_SIZE, 23, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jScrollPane2, javax.swing.GroupLayout.PREFERRED_SIZE, 105, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(Totalharga, javax.swing.GroupLayout.PREFERRED_SIZE, 21, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(Bayar, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jButton3)
.addGap(11, 11, 11)
.addComponent(Kembalian, javax.swing.GroupLayout.PREFERRED_SIZE, 22, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap())
);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(12, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
);
pack();
setLocationRelativeTo(null);
}// </editor-fold>
private void BayarActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
}
private void NamaActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
}
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
// Tombol Input untuk masukkan data yang di input oleh user ke tabel
Pesan.setText("");
DefaultTableModel a = (DefaultTableModel) jTable1.getModel();
if(Nama.getText().trim().equals("")){
Pesan.setText("MAAF, NAMA BARANG HARUS DI ISI");
}else{
int c = Integer.parseInt(Harga.getText());
int b = Integer.parseInt(Qty.getText());
int d = b * c;
Jumlah.setText(""+d);
Jumlah.setVisible(false);
int t = 0;
Vector z = new Vector();
z.add(Nama.getText());
z.add("Rp.".concat(Harga.getText()));
z.add(Qty.getText());
z.add("Rp.".concat(Jumlah.getText()));
a.addRow(z);
for(int e = 0; e <a.getRowCount(); e++){
t += Integer.parseInt(a.getValueAt(e, 3).toString().substring(3));
}
Totalharga.setText("Rp."+t);
Nama.setText("");
Harga.setText("");
Qty.setText("");
}
}
private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {
// Hapus
//DefaultTableModel a = (DefaultTableModel) jTable1.getModel();
DefaultTableModel a = (DefaultTableModel) jTable1.getModel();
int select = jTable1.getSelectedRow();
a.removeRow(select);
Nama.setText("");
Harga.setText("");
Qty.setText("");
int t= 0;
for(int e = 0; e <a.getRowCount(); e++){
t += Integer.parseInt(a.getValueAt(e, 3).toString().substring(3));
}
Totalharga.setText("Rp."+t);
int g = Integer.parseInt(Totalharga.getText().substring(3));
int f = Integer.parseInt(Bayar.getText());
int h = f - g;
Kembalian.setText("Rp."+h);
}
private void BayarKeyTyped(java.awt.event.KeyEvent evt) {
// tertekan di kolom bayar
Pesan.setText("");
char a = evt.getKeyChar();
int b = evt.getKeyCode() ;
if(!Character.isDigit(a)){
evt.consume();
Pesan.setText("maaf hanya bisa input pakai angka");
} else if (b == VK_BACK_SPACE) {
evt.consume();
Pesan.setText("maaf hanya bisa input pakai angka");
}
}
private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
int g = Integer.parseInt(Totalharga.getText().substring(3));
int f = Integer.parseInt(Bayar.getText());
int h = f - g;
Kembalian.setText("Rp."+h);
}
private void QtyKeyTyped(java.awt.event.KeyEvent evt) {
// Qty terketik
Pesan.setText("");
char a = evt.getKeyChar();
int b = evt.getKeyCode() ;
if(!Character.isDigit(a)){
evt.consume();
Pesan.setText("maaf hanya bisa input pakai angka");
} else if (b == VK_BACK_SPACE) {
evt.consume();
Pesan.setText("maaf hanya bisa input pakai angka");
}
}
private void HargaKeyTyped(java.awt.event.KeyEvent evt) {
// TODO add your handling code here:
Pesan.setText("");
char a = evt.getKeyChar();
int b = evt.getKeyCode() ;
if(!Character.isDigit(a)){
evt.consume();
Pesan.setText("maaf hanya bisa input pakai angka");
} else if (b == VK_BACK_SPACE) {
evt.consume();
Pesan.setText("maaf hanya bisa input pakai angka");
}
}
private void BayarKeyPressed(java.awt.event.KeyEvent evt) {
// TODO add your handling code here:
}
private void HargaActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
}
private void HargaKeyPressed(java.awt.event.KeyEvent evt) {
// TODO add your handling code here:
}
private void QtyKeyPressed(java.awt.event.KeyEvent evt) {
// TODO add your handling code here:
}
private void QtyActionPerformed(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 | InstantiationException | IllegalAccessException | javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(kasirJframe.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new kasirJframe().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JTextField Bayar;
private javax.swing.JTextField Harga;
private javax.swing.JLabel Jumlah;
private javax.swing.JLabel Kembalian;
private javax.swing.JTextField Nama;
private javax.swing.JLabel Pesan;
private javax.swing.JTextField Qty;
private javax.swing.JLabel Totalharga;
private javax.swing.JButton jButton1;
private javax.swing.JButton jButton2;
private javax.swing.JButton jButton3;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JPanel jPanel1;
private javax.swing.JScrollPane jScrollPane2;
private javax.swing.JTable jTable1;
// End of variables declaration
void isVisible(boolean b) {
throw new UnsupportedOperationException("Not supported yet."); //To
change body of generated methods, choose Tools | Templates.
}
}
当我在用户界面窗口或jframe或设计中按下jButton1或按钮“Input”时，在输出窗口选项卡中给出了这个错误。
Exception in thread "AWT-EventQueue-0" java.lang.NumberFormatException: For input string: " 1"
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
at java.lang.Integer.parseInt(Integer.java:569)
at java.lang.Integer.parseInt(Integer.java:615)
at kasiraldo.kasirJframe.jButton1ActionPerformed(kasirJframe.java:264)
at kasiraldo.kasirJframe.access$700(kasirJframe.java:15)
at kasiraldo.kasirJframe$6.actionPerformed(kasirJframe.java:97)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2348)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
at java.awt.Component.processMouseEvent(Component.java:6533)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3324)
at java.awt.Component.processEvent(Component.java:6298)
at java.awt.Container.processEvent(Container.java:2236)
at java.awt.Component.dispatchEventImpl(Component.java:4889)
at java.awt.Container.dispatchEventImpl(Container.java:2294)
at java.awt.Component.dispatchEvent(Component.java:4711)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4888)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4525)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4466)
at java.awt.Container.dispatchEventImpl(Container.java:2280)
at java.awt.Window.dispatchEventImpl(Window.java:2746)
at java.awt.Component.dispatchEvent(Component.java:4711)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
at java.awt.EventQueue.access$500(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:709)
at java.awt.EventQueue$3.run(EventQueue.java:703)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:90)
at java.awt.EventQueue$4.run(EventQueue.java:731)
at java.awt.EventQueue$4.run(EventQueue.java:729)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)
BUILD SUCCESSFUL (total time: 9 seconds)
对不起，如果我的问题看起来很模糊......
答案 0 :(得分：1)
您已将Qty文本字段的默认值设置为" "（一个空格）。
Qty.setText(" ");
您可能会在该文本字段中添加1并按下提交按钮以触发jButton1ActionPerformed方法。您正在尝试将文本" 1"解析为导致java.lang.NumberFormatException: For input string: " 1"异常的整数 -
int b = Integer.parseInt(Qty.getText());
简单的解决方案会将""（空白）设置为Qty文本字段 -
Qty.setText("");
它应该可以正常工作。
答案 1 :(得分：0)
java.lang.NumberFormatException: For input string: " 1"
实际上，这说明了一切："1"可以解析为数字，但添加了空格" 1"，这是纯文本String，而不是数字格式化了。
在您要解析的trim()上调用String，以删除前导和尾随空格。