java 输入任意字符串找回文

package com.hidata.devops.paas; import java.util.ArrayList; import java.util.Scanner; public class Testssk { public static void main(String[] args) { ArrayList<String> arr = new ArrayList<String>(); Scanner sc = new Scanner(System.in); System.out.println("请输入任意40个字符："); String str = sc.next(); int len = str.length(); for(int i=0;i<len;i++) { for(int j=i+1;j<=len;j++) { String now = str.substring(i,j); if(isHw(now)) { arr.add(now); } } } for(String s:arr) { System.out.println(s); } } public static boolean isHw(String s) { for(int i=0;i<s.length()/2;i++) { if(s.charAt(i)!=s.charAt(s.length()-1-i)) { return false; } } return true; } }