How to decode the following

Ruchi, the message is coded by first converting it to the opposite case and then getting its ASCII code. To decode the string you should start by first converting the given ASCII code to it's equivalent character and then converting it to its opposite case. Give it a try and if it doesn't work, paste your code here. We'll help you with this.

Thanks a lot !! I really needed it

import java.util.*;
class decription
{
void display()
{
Scanner sc=new Scanner (System.in);
System.out.println("Enters encrypted data");
String s=sc.nextLine();
String s2="";
int b=0;
for(int i=0;i<s.length();i++)
{
String s1=s.substring(b,i+1);
int a=Integer.parseInt(s1);
if((a>=65 && a<=90) || (a>=97 && a<=122) || (a==32) )
{
s2=s2+(char)a;
b=i+1;
}
else
{
continue;
}
}
System.out.println(s2);
}
}