input String from Console with Scanner - Java Language Basics

Java examples for Language Basics:Console

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Description

input String from Console with Scanner

Demo Code


//package com.java2s;

import java.util.Scanner;

public class Main {
    public static void main(String[] argv) throws Exception {
        String question = "java2s.com";
        String regex = "java2s.com";
        System.out.println(inputString(question, regex));
    }//ww  w.  j a va 2 s  . c  o m

    public static String inputString(String question, String regex) {
        return inputString(question, regex, "");
    }

    public static String inputString(String question, String regex,
            String help) {
        String answer = "";
        boolean matches = false;
        System.out.print(messageBox(question));
        while (!matches) {
            answer = new Scanner(System.in).next();
            if (answer.matches(regex)) {
                matches = true;
            } else {
                System.out.print(messageBox(help, question));
            }
        }

        return question;
    }

    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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