详解尚硅谷项目二: 客户信息管理软件 其四 CMUtility工具类

视频中的readKeyBoard方法不能使用

完整代码如下

public class CMUtility {
    private static Scanner scanner = new Scanner(System.in);
    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.println("输入长度(不大于" + limit + ")错误,请重新输入");
                continue;
            }
            break;
        }
        return line;
    }
    
    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' && c != '5') {
                System.out.println("选择错误,请重新输入: ");
            } else {
                break;
            }
        }
        return c;
    }
    
    public static char readChar() {
        String str = readKeyBoard(1,false);
        return str.charAt(0);
    }
    
    public static char readChar(char defaultValue) {
        String str = readKeyBoard(1,true);
        return (str.length() == 0) ? defaultValue : str.charAt(0);
    }
    
    public static int readInt() {
        int n;
        for ( ; ; ){
            String str = readKeyBoard(2,false);
            try {
                n = Integer.parseInt(str);
                break;
            } catch (NumberFormatException e) {
                System.out.println("数字输入错误,请重新输入");
            }
        }
        return n;
    }
    
    public static int readInt(int defaultValue) {
        int n;
        for ( ; ; ){
            String str = readKeyBoard(2,true);
            if (str.equals("")) {
                return defaultValue;
            }
            try {
                n = Integer.parseInt(str);
                break;
            } catch (NumberFormatException e) {
                System.out.println("数字输入错误,请重新输入");
            }
        }
        return n;
    }
    
    public static String readString(int limit){
        return readKeyBoard(limit,false);
    }
    
    public static String readString(int limit,String defaultValue){
        String str = readKeyBoard(limit,true);
        return (str.length() == 0) ? defaultValue : str;
    }
    
    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.println("选择错误,请重新输入: ");
            }
        }
        return c;
    }
}