JAVA Reverse

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

public class StringPractice {

public static void main(String[] args) throws IOException {
// TODO Auto-generated method stub
BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
System.out.println("input sth");
String st=br.readLine();
System.out.println(StringReverse(st));

}

public static String StringReverse(String s){
 
  //根据字符串s的长度定义char数组的长度
 
  char[] chs = new char[s.toCharArray().length];
  //循环截取字符，逆序赋值给字符数组chs
  for(int i=0;i<s.length();i++){
   int j = s.length()-1-i;
   chs[j] = s.charAt(i);
  
  }
  //根据chs数组构造新字符串s1
  String s1 = new String(chs);
 
  return s1;
 
}

}