package com.atguigu.util;

import java.util.*;

public class TSUtility {

    private static Scanner scanner = new Scanner(System.in);

public static char readMenuSelection() {

        char c;

        for (; ; ) {

            String str = readKeyBoard(1, false);

            c = str.charAt(0);

            if (c != '1' && c != '2' &&

                c != '3' && c != '4') {

                System.out.print("选择错误，请重新输入：");

            } else break;

        }

        return c;

    }

    public static void readReturn() {

        System.out.print("按回车键继续...");

        readKeyBoard(100, true);

    }

    public static int readInt() {

        int n;

        for (; ; ) {

            String str = readKeyBoard(2, false);

            try {

                n = Integer.parseInt(str);

                break;

            } catch (NumberFormatException e) {

                System.out.print("数字输入错误，请重新输入：");

            }

        }

        return n;

    }

    public static char readConfirmSelection() {

        char c;

        for (; ; ) {

            String str = readKeyBoard(1, false).toUpperCase();

            c = str.charAt(0);

            if (c == 'Y' || c == 'N') {

                break;

            } else {

                System.out.print("选择错误，请重新输入：");

            }

        }

        return c;

    }

    private static String readKeyBoard(int limit, boolean blankReturn) {

        String line = "";

        while (scanner.hasNextLine()) {

            line = scanner.nextLine();

            if (line.length() == 0) {

                if (blankReturn) return line;

                else continue;

            }

            if (line.length() < 1 || line.length() > limit) {

                System.out.print("输入长度（不大于" + limit + "）错误，请重新输入：");

                continue;

            }

            break;

        }

        return line;

    }

}