question: static String extractPossibleNumber ( String number ) { Matcher m = VALID_START_CHAR_PATTERN . matcher ( number ) ; if ( m . find ( ) ) { number = number . substring ( m . start ( ) ) ; Matcher trailingCharsMatcher = UNWANTED_END_CHAR_PATTERN . matcher ( number ) ; if ( trailingCharsMatcher . find ( ) ) { number = number . substring ( 0 , trailingCharsMatcher . start ( ) ) ; logger . log ( Level . FINER , "Stripped trailing characters: " + number ) ; } Matcher secondNumber = SECOND_NUMBER_START_PATTERN . matcher ( number ) ; if ( secondNumber . find ( ) ) { number = number . substring ( 0 , secondNumber . start ( ) ) ; } return number ; } else { return "" ; } }
target:  Attempts to extract a possible number from the string passed in. This currently strips all leading characters that cannot be used to start a phone number. Characters that can be used to start a phone number are defined in the VALID_START_CHAR_PATTERN. If none of these characters are found in the number passed in, an empty string is returned. This function also attempts to strip off any alternative extensions or endings if two or more are present, such as in the case of: (530) 583-6985 x302/x2303. The second extension here makes this actually two phone numbers, (530) 583-6985 x302 and (530) 583-6985 x2303. We remove the second extension so that the first number is parsed correctly.