JOptionPane - Cancel button error

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JOptionPane - Cancel button error

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#1 by (2 votes)
#2 by (0 votes)

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I'm developing an ATM system with JFrame , however when I use a JOptionPane , when I click the cancel button it appears some errors in the Eclipse console.

Follow the errors below:

Exception in thread "AWT-EventQueue-0" java.lang.NumberFormatException: null
    at java.lang.Integer.parseInt(Unknown Source)
    at java.lang.Integer.parseInt(Unknown Source)
    at CaixaEletronico.CaixaEletronico.sacar(CaixaEletronico.java:150)
    at CaixaEletronico.GUI$2.actionPerformed(GUI.java:66)
    at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
    at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
    at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
    at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
    at java.awt.Component.processMouseEvent(Unknown Source)
    at javax.swing.JComponent.processMouseEvent(Unknown Source)
    at java.awt.Component.processEvent(Unknown Source)
    at java.awt.Container.processEvent(Unknown Source)
    at java.awt.Component.dispatchEventImpl(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
    at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
    at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Window.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
    at java.awt.EventQueue.access$500(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue$4.run(Unknown Source)
    at java.awt.EventQueue$4.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue.dispatchEvent(Unknown Source)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.run(Unknown Source)

The code:

do {
    valorTotal = ((caixa[0][1]*100)+(caixa[1][1]*50)+(caixa[2][1]*20)+(caixa[3][1]*10)+(caixa[4][‌1]*5)+(caixa[5][1]*2));
    valorSaque = Integer.parseInt(JOptionPane.showInputDialog("Digite valor de saque:"));
    if(valorSaque == 0){
        JOptionPane.showMessageDialog(null, "Digite um valor para efetuar o saque!");
    } else{
        if(valorTotal < cotaMin){
            JOptionPane.showMessageDialog(null, "Caixa Vazio: Chame o Operador");
            return null;
        }
        if(valorSaque > valorTotal){
            JOptionPane.showMessageDialog(null, "Saque não realizado por falta de cédulas");
            return null;
        }

java

asked by anonymous 21.05.2015 / 04:51

2 answers

2

In your code there should be something like this:

int valor = Integer.parseInt(JOptionPane.showInputDialog("Digite um número"));

Or so:

String digitado = JOptionPane.showInputDialog("Digite um número");
int valor = Integer.parseInt(digitado);

It turns out that if you click the cancel button, showInputDialog will return null and when you try to Integer.parseInt(null) , a NumberFormatException is released. Here's what you can do to get around this:

String digitado = JOptionPane.showInputDialog("Digite um número");
if (digitado == null) {
    JOptionPane.showMessageDialog(null, "Cancelado...");
} else {
    int valor = Integer.parseInt(digitado);
    // ...
}

Or else:

String digitado = JOptionPane.showInputDialog("Digite um número");
int valor = digitado == null ? 0 : Integer.parseInt(digitado);

Your code contains this:

valorSaque = Integer.parseInt(JOptionPane.showInputDialog("Digite valor de saque:"));

To tidy up, just use this instead:

String digitado = JOptionPane.showInputDialog("Digite valor de saque:");
valorSaque = digitado == null ? 0 : Integer.parseInt(digitado);

21.05.2015 / 05:03

Error handling in the Google maps Android API Handling Data Array PDO CRUD

score 0 · Accepted Answer

With your code in hand, it gets easier. See the fix:

valorTotal = ((caixa[0][1] * 100) + (caixa[1][1] * 50) + (caixa[2][1] * 20) + (caixa[3][1] * 10) + (caixa[4][‌1] * 5) + (caixa[5][1] * 2));
int valorSaque = 0;
valorSaqueString = JOptionPane.showInputDialog("Digite valor de saque:");
if (valorSaqueString == null) {
    JOptionPane.showMessageDialog(null, "Ação cancelada");
} else if ((valorSaque = Integer.parseInt(valorSaqueString)) == 0) {
    JOptionPane.showMessageDialog(null, "Digite um valor para efetuar o saque!");
} else {
    if (valorTotal < cotaMin) {
        JOptionPane.showMessageDialog(null, "Caixa Vazio: Chame o Operador");
        return null;
    }
    if (valorSaque > valorTotal) {
        JOptionPane.showMessageDialog(null, "Saque não realizado por falta de cédulas");
        return null;
    }
}