rotN.java

public class rotN{   
    public static String encode(String s, int offset) {
	s.toLowerCase();
	String returnstring = "";
	for (char i : s.toCharArray()) {
	    if (i > 96 && i < 123) {
		int j = i + offset;
		if (j > 122) 
		    j = j - 26;
		returnstring = returnstring + Character.toString((char)j);
	    }
	    else
		returnstring = returnstring + Character.toString((char)i);
	}
	return returnstring;
    }
   
    public static void main(String[] args) {
	System.out.println(encode("hello",3));
	System.out.println(encode("abcxyz",3));
    }
}