How can I validate that only between numbers

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How can I validate that only between numbers

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#1 by (0 votes)

1

This is my code. It only works for me once to validate; if I enter a data type String , when I return to enter a string it gives an error.

public class BienvenidaSegundo {

    static String nombre;
    static int caso;

    public static void main(String[] args) {
        boolean repetir = true;
        while (repetir) {
            try {
                caso = Integer.parseInt(JOptionPane.showInputDialog("Ingrese la manera quiere imprimir la bienvenida(1-scanner,2-Panel)"));
                validar();
                repetir = false;
            } catch (HeadlessException | NumberFormatException e) {
                JOptionPane.showMessageDialog(null, "Cadena ingresada, debe ingresar un valor numerico", "Informacion", JOptionPane.INFORMATION_MESSAGE);
                caso = Integer.parseInt(JOptionPane.showInputDialog("Ingrese la manera quiere imprimir la bienvenida(1-scanner,2-Panel)"));

            }

        }
    }

    private static void operacionPanel() {
        nombre = "";
        while (nombre.equals("")) {
            nombre = JOptionPane.showInputDialog("Ingrese Nombre");
            JOptionPane.showMessageDialog(null, "Bienvenido " + nombre, "Informacion", JOptionPane.INFORMATION_MESSAGE);
        }
    }

    private static void operacionScanner() {
        Scanner entrada = new Scanner(System.in);
        String nombre1 = "";
        while (nombre1.equals("")) {
            System.out.println("Ingrese Nombre");
            nombre1 = entrada.nextLine();
        }
        System.out.println("Bienvenido " + nombre1);

    }

    private static void validar() {
        while (caso < 1 || caso > 2) {
            JOptionPane.showMessageDialog(null, "Ingrese un numero valido", "Error", JOptionPane.ERROR_MESSAGE);
            caso = Integer.parseInt(JOptionPane.showInputDialog("Ingrese la manera quiere imprimir la bienvenida(1-scanner,2-Panel)"));
        }
        switch (caso) {
            case 1:
                operacionScanner();
                break;
            case 2:
                operacionPanel();
                break;
        }
    }
}

The error it throws is:

run: Exception in thread "main" java.lang.NumberFormatException: For input string: "h"
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
at java.lang.Integer.parseInt(Integer.java:580)
at java.lang.Integer.parseInt(Integer.java:615)
at bienvenidasegundo.BienvenidaSegundo.main(BienvenidaSegundo.java:21)
C:\Users\Hitler\AppData\Local\NetBeans\Cache.2\executor-snippets\run.xml:53: Java returned: 1
BUILD FAILED (total time: 7 seconds)

java poo

asked by Agustin Ozuna Leguizamón 04.05.2018 в 02:09

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1 answer

Receive emails from gmail display a message instead of displaying the result of the search in a gridview

score 0 · Accepted Answer

In the main of your class you are repeating an unnecessary instruction for your cycle. That second caso is within the catch and, in turn, is not surrounded by any try-catch that catches the exception, so it just fails.

If you comment | delete the last caso , the cycle is responsible for showing the message again asking for the option to process the name.

public static void main(String[] args) {
        boolean repetir = true;
        while (repetir) {
            try {
                caso = Integer.parseInt(JOptionPane.showInputDialog("Ingrese la manera quiere imprimir la bienvenida(1-scanner,2-Panel)"));
                validar();
                repetir = false;
            } catch (HeadlessException | NumberFormatException e) {
                JOptionPane.showMessageDialog(null, "Cadena ingresada, debe ingresar un valor numerico", "Informacion", JOptionPane.INFORMATION_MESSAGE);
//                caso = Integer.parseInt(JOptionPane.showInputDialog("Ingrese la manera quiere imprimir la bienvenida(1-scanner,2-Panel)"));

            }

        }
    }