Help calling a string to another method.

Well I am back. I need to get the string encodedString from the method encode able to be used in the decode method.

Java Code:

   public String encode(String plainText)  
   {
      int prepareString;
      int shiftChar;
      String preparedString2 = prepareString(plainText);
      
      String encodedString = ""; 
      for(int c = 0 ; c < preparedString2.length();c++)
      if(Character.isAlphabetic(preparedString2.charAt(c)))
      {   
         encodedString = encodedString+shiftChar(preparedString2.charAt(c),shift); 
      }
      return encodedString; 
   }
   public String decode(String cipherText)
   {
      
      String cipherText = "";
      for(int z = 0 ; z < encodedString.length();z++)
      if(Character.isAlphabetic(encodedString.charAt(z)))
      {
          cipherText = cipherText+shiftChar(encodedString.charAt(z),-shift);
      }
      return cipherText;
   }   
}