Hi I have tried Looking for a solution online but it doesn't seem to apply to my problem
I am trying to use a straightforward getText from a textfield in my JForm when I press the register button it works if i try to get the value from the method addCustomer() but in the addCustomer() i have a method called isValid() which checks that it can be added it is here that the txtFullName.getText() does not work with the NullPointerException.
I have tried getting the text value from the addCustomer() using String name = txtFullName.getText() and passing that as a parameter to the isValid() this does work but I don't want to have to pass every variable that i want checking.
I just want to be able to use the standard getText method to do this.
This line is the problem:
if (txtFullName.getText().length() > 0)
Here is the code for the CustomerRegistration Class that is throwing the error:
/*
* 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 gui;
import dataModel.Customer;
import dataModel.Person;
import javax.swing.JOptionPane;
/**
*
* @author Rich
*/
public class CustomerRegistration extends javax.swing.JFrame {
Person customerList = new Person();
/**
* Creates new form CustomerRegistration
*/
public CustomerRegistration() {
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() {
pnlAddress = new javax.swing.JPanel();
lblAddressLine1 = new javax.swing.JLabel();
txtAddressLine1 = new javax.swing.JTextField();
txtAddressLine2 = new javax.swing.JTextField();
lblAddressLine2 = new javax.swing.JLabel();
lblAddressLine3 = new javax.swing.JLabel();
txtAddressLine3 = new javax.swing.JTextField();
lblTownCity = new javax.swing.JLabel();
txtTownCity = new javax.swing.JTextField();
lblPostcode = new javax.swing.JLabel();
txtPostcode = new javax.swing.JTextField();
pnlCustomerDetails = new javax.swing.JPanel();
lblFullName = new javax.swing.JLabel();
lblEmail = new javax.swing.JLabel();
txtEmail = new javax.swing.JTextField();
lblCostPerKg = new javax.swing.JLabel();
txtCostPerKg = new javax.swing.JTextField();
txtFullName = new javax.swing.JTextField();
lblCustomerDetails = new javax.swing.JLabel();
lblCustomerRegistration = new javax.swing.JLabel();
btnCancel = new javax.swing.JButton();
lblAddressDetails = new javax.swing.JLabel();
btnRegister = new javax.swing.JButton();
txtTest = new javax.swing.JTextField();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
pnlAddress.setBorder(javax.swing.BorderFactory.createEtchedBorder());
lblAddressLine1.setFont(new java.awt.Font("Arial", 0, 12)); // NOI18N
lblAddressLine1.setText("Address Name/Number:");
lblAddressLine2.setFont(new java.awt.Font("Arial", 0, 12)); // NOI18N
lblAddressLine2.setText("Address Line 1:");
lblAddressLine3.setFont(new java.awt.Font("Arial", 0, 12)); // NOI18N
lblAddressLine3.setText("Address Line 2:");
lblTownCity.setFont(new java.awt.Font("Arial", 0, 12)); // NOI18N
lblTownCity.setText("Town / City:");
lblPostcode.setFont(new java.awt.Font("Arial", 0, 12)); // NOI18N
lblPostcode.setText("Postcode:");
javax.swing.GroupLayout pnlAddressLayout = new javax.swing.GroupLayout(pnlAddress);
pnlAddress.setLayout(pnlAddressLayout);
pnlAddressLayout.setHorizontalGroup(
pnlAddressLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(pnlAddressLayout.createSequentialGroup()
.addGap(48, 48, 48)
.addGroup(pnlAddressLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(pnlAddressLayout.createSequentialGroup()
.addComponent(lblAddressLine1)
.addGap(18, 18, 18)
.addComponent(txtAddressLine1))
.addGroup(pnlAddressLayout.createSequentialGroup()
.addComponent(lblPostcode)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(txtPostcode, javax.swing.GroupLayout.PREFERRED_SIZE, 196, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(pnlAddressLayout.createSequentialGroup()
.addComponent(lblAddressLine2)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(txtAddressLine2, javax.swing.GroupLayout.PREFERRED_SIZE, 196, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(pnlAddressLayout.createSequentialGroup()
.addComponent(lblAddressLine3)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(txtAddressLine3, javax.swing.GroupLayout.PREFERRED_SIZE, 196, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(pnlAddressLayout.createSequentialGroup()
.addComponent(lblTownCity)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(txtTownCity, javax.swing.GroupLayout.PREFERRED_SIZE, 196, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addContainerGap())
);
pnlAddressLayout.setVerticalGroup(
pnlAddressLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(pnlAddressLayout.createSequentialGroup()
.addContainerGap()
.addGroup(pnlAddressLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(lblAddressLine1)
.addComponent(txtAddressLine1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addGroup(pnlAddressLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(lblAddressLine2)
.addComponent(txtAddressLine2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addGroup(pnlAddressLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(lblAddressLine3)
.addComponent(txtAddressLine3, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addGroup(pnlAddressLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(lblTownCity)
.addComponent(txtTownCity, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addGroup(pnlAddressLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(lblPostcode)
.addComponent(txtPostcode, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
);
pnlCustomerDetails.setBorder(javax.swing.BorderFactory.createEtchedBorder());
lblFullName.setFont(new java.awt.Font("Arial", 0, 12)); // NOI18N
lblFullName.setText("Full Name:");
lblEmail.setFont(new java.awt.Font("Arial", 0, 12)); // NOI18N
lblEmail.setText("Email:");
lblCostPerKg.setFont(new java.awt.Font("Arial", 0, 12)); // NOI18N
lblCostPerKg.setText("Cost Per KG:");
javax.swing.GroupLayout pnlCustomerDetailsLayout = new javax.swing.GroupLayout(pnlCustomerDetails);
pnlCustomerDetails.setLayout(pnlCustomerDetailsLayout);
pnlCustomerDetailsLayout.setHorizontalGroup(
pnlCustomerDetailsLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(pnlCustomerDetailsLayout.createSequentialGroup()
.addContainerGap(46, Short.MAX_VALUE)
.addGroup(pnlCustomerDetailsLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, pnlCustomerDetailsLayout.createSequentialGroup()
.addGroup(pnlCustomerDetailsLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, pnlCustomerDetailsLayout.createSequentialGroup()
.addComponent(lblFullName)
.addGap(11, 11, 11))
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, pnlCustomerDetailsLayout.createSequentialGroup()
.addComponent(lblEmail)
.addGap(36, 36, 36))
.addComponent(lblCostPerKg))
.addGroup(pnlCustomerDetailsLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(pnlCustomerDetailsLayout.createSequentialGroup()
.addGap(78, 78, 78)
.addComponent(txtCostPerKg, javax.swing.GroupLayout.PREFERRED_SIZE, 56, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(pnlCustomerDetailsLayout.createSequentialGroup()
.addGap(77, 77, 77)
.addComponent(txtFullName, javax.swing.GroupLayout.PREFERRED_SIZE, 200, javax.swing.GroupLayout.PREFERRED_SIZE))))
.addComponent(txtEmail, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.PREFERRED_SIZE, 202, javax.swing.GroupLayout.PREFERRED_SIZE))
.addContainerGap())
);
pnlCustomerDetailsLayout.setVerticalGroup(
pnlCustomerDetailsLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(pnlCustomerDetailsLayout.createSequentialGroup()
.addContainerGap()
.addGroup(pnlCustomerDetailsLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(lblFullName)
.addComponent(txtFullName, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(18, 18, 18)
.addGroup(pnlCustomerDetailsLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(lblEmail)
.addComponent(txtEmail, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(18, 18, 18)
.addGroup(pnlCustomerDetailsLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(lblCostPerKg)
.addComponent(txtCostPerKg, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
);
lblCustomerDetails.setFont(new java.awt.Font("Arial", 1, 12)); // NOI18N
lblCustomerDetails.setText("Customer Details:");
lblCustomerRegistration.setFont(new java.awt.Font("Arial", 1, 18)); // NOI18N
lblCustomerRegistration.setText("Customer Registration");
btnCancel.setText("Cancel");
lblAddressDetails.setFont(new java.awt.Font("Arial", 1, 12)); // NOI18N
lblAddressDetails.setText("Address Details:");
btnRegister.setText("Register");
btnRegister.addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseClicked(java.awt.event.MouseEvent evt) {
btnRegisterMouseClicked(evt);
}
});
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(165, 165, 165)
.addComponent(lblCustomerRegistration)
.addGap(74, 74, 74)
.addComponent(txtTest, javax.swing.GroupLayout.PREFERRED_SIZE, 72, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createSequentialGroup()
.addGap(64, 64, 64)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(lblCustomerDetails)
.addComponent(pnlCustomerDetails, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(lblAddressDetails)
.addComponent(pnlAddress, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)))
.addGroup(layout.createSequentialGroup()
.addGap(144, 144, 144)
.addComponent(btnCancel, javax.swing.GroupLayout.PREFERRED_SIZE, 92, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addComponent(btnRegister, javax.swing.GroupLayout.PREFERRED_SIZE, 92, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addContainerGap(68, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(lblCustomerRegistration))
.addGroup(layout.createSequentialGroup()
.addGap(24, 24, 24)
.addComponent(txtTest, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addGap(8, 8, 8)
.addComponent(lblCustomerDetails)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(pnlCustomerDetails, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addComponent(lblAddressDetails)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(pnlAddress, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(btnCancel)
.addComponent(btnRegister))
.addContainerGap(38, Short.MAX_VALUE))
);
pack();
}// </editor-fold>
private void btnRegisterMouseClicked(java.awt.event.MouseEvent evt) {
addCustomer();
}
/**
* @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(CustomerRegistration.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(CustomerRegistration.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(CustomerRegistration.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(CustomerRegistration.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 CustomerRegistration().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton btnCancel;
private javax.swing.JButton btnRegister;
private javax.swing.JLabel lblAddressDetails;
private javax.swing.JLabel lblAddressLine1;
private javax.swing.JLabel lblAddressLine2;
private javax.swing.JLabel lblAddressLine3;
private javax.swing.JLabel lblCostPerKg;
private javax.swing.JLabel lblCustomerDetails;
private javax.swing.JLabel lblCustomerRegistration;
private javax.swing.JLabel lblEmail;
private javax.swing.JLabel lblFullName;
private javax.swing.JLabel lblPostcode;
private javax.swing.JLabel lblTownCity;
private javax.swing.JPanel pnlAddress;
private javax.swing.JPanel pnlCustomerDetails;
private javax.swing.JTextField txtAddressLine1;
private javax.swing.JTextField txtAddressLine2;
private javax.swing.JTextField txtAddressLine3;
private javax.swing.JTextField txtCostPerKg;
private javax.swing.JTextField txtEmail;
private javax.swing.JTextField txtFullName;
private javax.swing.JTextField txtPostcode;
private javax.swing.JTextField txtTest;
private javax.swing.JTextField txtTownCity;
// End of variables declaration
public void addCustomer() {
txtFullName.getText();
if(this.isValid())
{
Person itemToAdd;
itemToAdd = new Customer(txtFullName.getText());
customerList.registerCustomer((Customer) itemToAdd);
JOptionPane.showMessageDialog(this, "Customer " + itemToAdd.getName() + " Added");
}
}
public boolean isValid()
{
Boolean blnValid = false;
// Check that name is of a valid format (eg. no numbers)
try
{
**if (txtFullName.getText().length() > 0)**
{
blnValid = true;
} else
{
throw new IllegalArgumentException("cannot be blank!");
}
} catch(NumberFormatException ex)
{
JOptionPane.showMessageDialog(this, "Full name can only contain letters", "Error Reading data", JOptionPane.ERROR_MESSAGE);
} catch (IllegalArgumentException ex)
{
JOptionPane.showMessageDialog(this, ex.getMessage(), "Invalid Data!", JOptionPane.ERROR_MESSAGE);
}
return blnValid;
}
}
