JAVA连位数字判断如，1234 ，7890，8901，9012求解决

如题，求高手解答在线等，我现在只实现了，1234这种的不能实现8901这种的，
public static boolean isDescNumeric(String numOrStr) {
boolean flag = true;
for (int i = 0; i < numOrStr.length(); i++) {
if (i > 0) {
int num = Integer.parseInt(numOrStr.charAt(i) + "");
int num_ = Integer.parseInt(numOrStr.charAt(i - 1) + "") - 1;
if (num != num_) {
flag = false;
break;
}
}
}
return flag;
}

所有输入都是false
你这是想要做什么判断？

 public static boolean isDescNumeric(String numOrStr) {
    boolean flag = true;
    for (int i = 0; i < numOrStr.length() -2; i++) {

        int num = Integer.parseInt(numOrStr.charAt(i) + "") + 1;
        int num_ = Integer.parseInt(numOrStr.charAt(i + 1) + "") ;
        if (num > 9){
             num = 1;
        }
        if (num != num_ ) {
            flag = false;
            break;
        }
    }

return flag;
}

就只有一种特殊情况，9到0
public static boolean isDescNumeric(String numOrStr) {
boolean flag = true;
for (int i = 0; i < numOrStr.length(); i++) {
if (i > 0) {
int num = Integer.parseInt(numOrStr.charAt(i) + "");
int num_ = Integer.parseInt(numOrStr.charAt(i - 1) + "") - 1;
if(num==9&&num_0==-1)
continue;//结束本次循环
if (num != num_) {
flag = false;
break;
}
}
}
return flag;
}

 public static boolean isDescNumeric(String numOrStr) 
{
    int start = (int)(numOrStr.charAt(0) + '0');
        for (int i = 0; i < numOrStr.length(); i++)
        {
            int n = (int)(numOrStr.charAt(i) + '0');
                if (n != (start + i) % 10) return false;
        }
        return true;
}

 /* package whatever; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
    public static boolean isDescNumeric(String numOrStr) 
    {
        int start = (int)(numOrStr.charAt(0) - '0');
        for (int i = 0; i < numOrStr.length(); i++)
        {
            int n = (int)(numOrStr.charAt(i) - '0');
            if (n != (start + i) % 10) return false;
        }
        return true;
    }
    public static void main (String[] args) throws java.lang.Exception
    {
        // your code goes here
        System.out.println(isDescNumeric("1234"));
        System.out.println(isDescNumeric("8901"));
        System.out.println(isDescNumeric("1345"));
    }
}

true
true
false

http://ideone.com/9HehGv
在线运行通过

我感觉应该这样吧，和楼上的大同小异，思路都差不多

 public static boolean  isDescNumeric(String numOrStr){
     //初始化标志位，默认所有的字符串都是连位的
     boolean isDesc = true;
     //将字符串转为数组，方便取用
     char[] numArr = numOrStr.toCharArray();
     //循环数组，判断是否为连位
     for(int i=0;i<numArr.length-1;i++){
        //当前字符位置
        int number = Integer.parseInt(numArr[i]);
        //数字当前位置的下一个
        int numberNext = Integer.parseInt(numArr[i+1]);
        //开始判断是否为连位
        int next = numberNext-1;
        //若当前位置为0，那么让它减去1后等于9
        if( next == -1){
            next = 9;
        }
        if(number ！= next){
            isDesc = false；
            break;
        }
     }
     return isDesc;
 }

不想写循环，换种思路玩玩。用空间来换，入参长度很大就要小心内存了。

 public class Test {

    public static boolean isDescNumeric(String numOrStr){
        String template = "0123456789";
        int size = (numOrStr.length() / template.length()) + 2;
        template = new String(new char[size]).replace("\0", template);
        return template.contains(numOrStr);
    }

    public static void main(String[] args) {

        System.out.println(isDescNumeric("1234"));
        System.out.println(isDescNumeric("8901"));
        System.out.println(isDescNumeric("1345"));

    }
}