input Int from Console using Scanner - Java Language Basics

Java examples for Language Basics:Console

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Description

input Int from Console using Scanner

Demo Code


//package com.java2s;
import java.util.InputMismatchException;
import java.util.Scanner;

public class Main {
    public static void main(String[] argv) throws Exception {
        String question = "java2s.com";
        System.out.println(inputInt(question));
    }//  ww  w.  j  a  v a2s.  c om

    public static int inputInt(String question) {
        int answer = -1;
        boolean matches = false;
        System.out.print(messageBox(question));
        while (!matches) {

            try {

                answer = new Scanner(System.in).nextInt();
                matches = true;
            } catch (InputMismatchException ex) {
                System.out.println(messageBox(
                        "Csak sz?mokat ?rhatsz be...!", question));
            }
        }

        return answer;
    }

    public static String messageBox(String... messages) {

        if (messages.length > 0) {
            int maxLength = messages[0].length();
            for (int i = 1; i < messages.length; i++) {
                if (maxLength < messages[i].length()) {
                    maxLength = messages[i].length();
                }
            }
            if (maxLength > 0) {
                StringBuilder sb = new StringBuilder("");
                sb.append(String.format("%s%-" + maxLength + "s%s", "+ ",
                        " ", " +\n").replace(" ", "-"));
                for (String message : messages) {
                    if (message.length() > 0) {
                        sb.append("| ")
                                .append(String.format("%-" + maxLength
                                        + "s", message)).append(" |\n");
                    }
                }
                sb.append(String.format("%s%-" + maxLength + "s%s", "+ ",
                        " ", " +").replace(" ", "-"));
                return sb.toString();
            }
        }
        return "+-+\n" + "| |\n" + "+-+";
    }
}

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