Check whether a given string is palindrome or not

//It can be done by three methods.
import java.util.Scanner;
class Palindrome
{
private boolean found=true;
void palByLogic(String s1)
{
char a[]=new char[s1.length()];
a=s1.toCharArray();
for(int i=0;i<s1.length()/2;i++)
{
if(a[i]!=a[s1.length()-i-1])
{
found=false;
break;
}
}
if(found==false)
System.out.println("not a palindrome:");
else
System.out.println("palindrome:");
}
void palByStBuffer(String s1)
{
StringBuffer s2=new StringBuffer(s1);
String s3=s2.reverse().toString();
if(s1.equals(s3))
System.out.println("Palindrome:");
else
System.out.println("Not a Palindrome:");
}
void palByStBuiler(String s1)
{
StringBuilder s2=new StringBuilder(s1);
String s3=s2.reverse().toString();
if(s1.equals(s3))
System.out.println("Palindrome:");
else
System.out.println("Not a Palindrome:");
}
}
class PalindromeTest
{
public static void main(String args[])
{
Palindrome p1=new Palindrome();
Scanner sc=new Scanner(System.in);
System.out.println("Enter the String:");
String s1=sc.next();
p1.palByLogic(s1);
p1.palByStBuffer(s1);
p1.palByStBuiler(s1);
}
}