code: private boolean isAlphanumericOrPlusMinusPoint(char character) {
          return (character >= 'A' && character <= 'Z') // Unicode A..Z
                  || (character >= 'a' && character <= 'z') // Unicode a..z
                  || (character >= '0' && character <= '9') // Unicode 0..9
                  || character == '+' || character == '-' || character == '.';
      }
docs: Checks whether a given character is in "+-." or an ASCII alphanumeric.
  This is useful for a check related to [RFC 2396]
  
  @param character The character to check.
  @return <code>true</code> if the character is in "+-." or an ASCII alphanumeric.