编写程序，判断输入的字符串是否回文

import java.util.Scanner;

public class WordsTest {
public static void main(String[] args) {
Scanner reader=new Scanner(System.in);
System.out.println("请输入一个字符串");
String s1=reader.next();
StringBuffer str=new StringBuffer(s1);
String s2=(str.reverse()).toString();
if(s1.equals(s2)){
System.out.println("该字符串回文");
}
else System.out.println("该字符串不回文");

}
}