Java - Rot94 - similar to rot13 - encode text

public class NinetyFiveEncode
{
 public NinetyFiveEncode()
 {
     String testStr = "The rain in Spain falls mainly on the plain. Call me at (555)112-xxxx. {:-) Bye.";
     String encoded = NinetyFiveEncode.rot94(testStr);
     System.out.println( encoded );
     String decoded = NinetyFiveEncode.rot94( encoded );
     System.out.println( decoded );
 }

 /*
  * Rot94 by Alan Lupsha (c)2009
  *
  * Takes a string of characters, and for every character
  * between ASCII value 33 and 126 (! to ~), it adds 94 to
  * the character value (wraps around if the result character
  * is larger than 126)
  *
  * Any non-printable characters and the space character
  * (i.e. any char smaller than 33 and larger than 126) gets
  * copied over.
  *
  * Sample run:
  *
  *  String testStr = "The rain in Spain falls mainly on the plain. Call me at (850)879-xxxx. {:-) Bye.";
  *  String encoded = NinetyFiveEncode.rot94(testStr);
  *  System.out.println( encoded );
  *  String decoded = NinetyFiveEncode.rot94( encoded );
  *  System.out.println( decoded );
  *
  * %96 C2:? :? $A2:? 72==D >2:?=J @? E96 A=2:?] r2== >6 2E Wgd_Xgfh\IIII] Li\X qJ6]
  * The rain in Spain falls mainly on the plain. Call me at (850)879-xxxx. {:-) Bye.
  */
 public static String rot94(String plainText)
 {
   if (plainText == null) return "";

   // encode plainText
   StringBuffer encodedMessage = new StringBuffer("");
   int abyte;
   for (int i = 0; i < abyte =" plainText.charAt(i);">= 33) && (abyte <= 126 ))
         abyte = (abyte - '!' + 47) % 94 + '!';
  
     encodedMessage.append( (char)abyte );
   }
   return encodedMessage.toString();
 }


 public static void main( String[] args )
 {
     NinetyFiveEncode ninetyFiveEncode = new NinetyFiveEncode();
 }
}