Question

我是java的新手，我已经嵌套了3次打印的Try Catch代码！你能告诉我为什么吗？我从命令行获得3 int并且必须进行验证并检查它们是否在范围内并且我正在使用try和catch。但答案打印3次！

// Global Constants
final static int MIN_NUMBER = 1;
final static int MAX_PRIME = 10000;
final static int MAX_FACTORIAL = 12;
final static int MAX_LEAPYEAR = 4000;

// Global Variable
static int a, b, c;

public static void main(String[] args) {
    // String[] myNumbers= new String [3];

    // int x =Integer.parseInt(args[0]);
    for (int i = 0; i < args.length; i++) {
        // System.out.print(args[i]+" ");
        validateInput(args[0], args[1], args[2]);

    }
}

// Validate User Input
public static boolean validateInput(String value1, String value2, String value3) {
    boolean isValid = false;

    try {
        try {
            try {
                a = Integer.parseInt(value1);
                if (!withinRange(a, MIN_NUMBER, MAX_PRIME)) {
                    System.out.println(
                            "The entered value " + value1
                            + " is out of range [1 TO 10000].");
                }
                isValid = true;         

            } catch (Exception ex) { 
                System.out.println(
                        "The entered value " + value1
                        + " is not a valid integer.  Please try again.");
            }   

            b = Integer.parseInt(value2);
            if (!withinRange(b, MIN_NUMBER, MAX_FACTORIAL)) {
                System.out.println(
                        "The entered value " + value2
                        + " is out of range [1 TO 12].");
            }
            isValid = true; 
        } catch (Exception ex) { 
            System.out.println(
                    "The entered value " + value2
                    + " is not a valid integer.  Please try again.");
        }

        c = Integer.parseInt(value3);
        if (!withinRange(c, MIN_NUMBER, MAX_LEAPYEAR)) {
            System.out.println(
                    "The entered value " + value3
                    + " is out of range [1 TO 4000].");
        }
        isValid = true; 
    } catch (Exception ex) { 
        System.out.println(
                "The entered value " + value3
                + " is not a valid integer.  Please try again.");
    }   

    return isValid;

}

// Check the value within the specified range
private static boolean withinRange(int value, int min, int max) {
    boolean isInRange = true; 

    if (value < min || value > max) {
        isInRange = false; 
    }
    return isInRange;
}

Answer 1

答案打印3次，因为您已将validateInput方法调用放入for中的main()循环中，如果有三个参数，则会运行三次。

Answer 2

我建议编写validateInput方法来验证单个字符串。为min和max允许的int值添加两个参数。

public static boolean validateInput(String value, int minValue, int maxValue) {
    try {
        integer intVal = Integer.parseInt(value);
        if (intVal < minVal || intVal > maxValue) {
            System.out.println("The entered value " + value
                + " is out of range [" + minValue + " TO " + maxValue + "].");

            return false;
        }
    } catch (Exception e) {
        System.out.println("The entered value " + value
            + " is not a valid integer. Please try again");
        return false;
    }
    return true;
}

嵌套尝试捕获

2 个答案: