Java 尝试使用“迭代”来迭代某个间隔；“边做边做”；

嗨，这段代码是我代码的一部分，它应该检查数字字符串是否是回文的。 我想从代码的顶部迭代到底部，但它根本不迭代，怎么了？？ 我在youtube上搜索并意识到这类事情，人们通常使用do-while循环，所以我试图按照说明进行操作，但它并没有给我想要的东西

do {
        System.out.println("You passed Catch-Block stage! , Please enter the number that you want to check if it is palindrome");

        String str = kbd.nextLine().trim();
        String org_str = str;
        String rev = "";
        int len = str.length();



            for (int i = len - 1; i >= 0; i--) {
                rev = rev + str.charAt(i);

            }
            if (org_str.equals(rev)) {
                System.out.println(org_str + " is Palindrome Number");

            } else {

                System.out.println(org_str + "is Not Palindrome String");

            }
            System.out.println("Do you want to continue Y or N");
            choice = kbd.next().charAt(0);
        }while(choice=='y'||choice =='Y');


        }

这是我的全部代码

package com.company;
import java.util.Scanner;
public class Main {

    public static void main(String[] args) {

        Scanner kbd = new Scanner(System.in);
        char choice;
        long firstNum = 0;

        firstNum = getLong(" Enter the first number: ", '-');


        do {
        System.out.println("You passed Catch-Block stage! , Please enter the number that you want to check if it is palindrome");

        String str = kbd.nextLine().trim();
        String org_str = str;
        String rev = "";
        int len = str.length();



            for (int i = len - 1; i >= 0; i--) {
                rev = rev + str.charAt(i);

            }
            if (org_str.equals(rev)) {
                System.out.println(org_str + " is Palindrome Number");

            } else {

                System.out.println(org_str + "is Not Palindrome String");

            }
            System.out.println("Do you want to continue Y or N");
            choice = kbd.next().charAt(0);
        }while(choice=='y'||choice =='Y');


        }

    public static long getLong(String prompt, char exitChar)
    {
        long retVal = 0;

        boolean validInput = false;

        String userInput = "";

        Scanner kbd = new Scanner(System.in);


        while (!validInput) {
            System.out.println(prompt);


            try
            {

                userInput = kbd.nextLine().trim();
                if (userInput.length() > 0 && userInput.charAt(0) == exitChar)
                {
                    System.out.println("Ending the program at the user's request");
                    System.exit(1);
                }

                retVal = Long.parseLong(userInput);
                validInput = true;
            }
            catch (Exception ex)
            {
                System.out.println("That is not numeric. Try again or press  " + exitChar + "to Quit");

            }



        }
        return retVal;
    }
}

更改此项：

String str = kbd.nextLine().trim();

对此

String str = kbd.next();

---

读取

选项时，使用
nextLine（）
intead of
next（）
：

do{
System.out.println（“您通过了Catch Block stage！，请输入要检查其是否为回文的数字”）；
字符串str=kbd.nextLine（）.trim（）；
字符串org_str=str；
字符串rev=“”；
int len=str.length（）；
对于（int i=len-1；i>=0；i--）{
rev=rev+str.charAt（i）；
}
如果（组织结构等于（修订））{
println（org_str+“是回文数”）；
}否则{
println（org_str+“不是回文字符串”）；
}
System.out.println（“您想继续Y还是N”）；
choice=kbd.nextLine（）.charAt（0）//
do {
    System.out.println("You passed Catch-Block stage! , Please enter the number that you want to check if it is palindrome");

    String str = kbd.nextLine().trim();
    String org_str = str;
    String rev = "";
    int len = str.length();



        for (int i = len - 1; i >= 0; i--) {
            rev = rev + str.charAt(i);

        }
        if (org_str.equals(rev)) {
            System.out.println(org_str + " is Palindrome Number");

        } else {

            System.out.println(org_str + "is Not Palindrome String");

        }
        System.out.println("Do you want to continue Y or N");
        choice = kbd.nextLine().charAt(0); // <---here, change to nextLine()
    }while(choice=='y'||choice =='Y');


    }