shared.formatting
Class DateFormatter

java.lang.Object
  shared.formatting.DateFormatter

public class DateFormatter
extends java.lang.Object

This class reformats dates into a standard form.

it reformats a string having the form MM/DD/YY or MM/DD/YYYY> to the form MM/DD/YYYY. It handles arbitrary non-digit input separators for parsing; a single "/" character is the default.

Conversion between two- and four-digit years is done by specifying a "first year in the epoch". Any two-digit year values are assumed to begin in the 100 years starting in that year. If no starting year for the epoch is provided, a default epoch beginning 49 years before the current year is assumed.

As an example, assume that the first year in the epoch is taken to be 1945. Any two digit years from "45" to "99" are assumed to be 1945 to 1999 (in the "first century"). All years from "00" to "44" are assumed to be 2000 to 2044 (in the "second century").

The date parsing itself uses Java's regular expression classes. The instance constructor uses the separator character provided by the caller to create regular expression patterns which will match the separator requested.

The 2- to 4-digit year processing is done by creating an instance of the inner Epoch class, initialized to perform conversions within the requested range of years.

The static variables are used to provide constant data shared among all class instances. The instance variables are set only in the constructors, and are not changed after that. This means that no synchronization is required when accessing either class or instance data from separate threads.

Nested Class Summary

protected class

DateFormatter.Epoch Convert between two- and four-digit years using a single year as the start of a two-digit epoch.

Field Summary

private static java.lang.String	defaultSeparator Default string which separates input dates.
private DateFormatter.Epoch	epoch The DateFormatter.Epoch in which to interpret two-digit years
private static java.lang.String	fourDigitYear Four-digit year pattern: exactly four digits.
private static java.lang.String	monthDay Month and day pattern: one or two digits.
private java.util.regex.Pattern	monthDayYear Month-day-year pattern, compiled with given input separator.
private java.util.regex.Pattern	monthYear Month-year pattern, compiled with given input separator.
private static java.lang.String	twoDigitYear Two-digit year pattern: exactly two digits.
private java.util.regex.Pattern	year Year pattern: two or four digits, no separator.

Constructor Summary

DateFormatter()
Default constructor.

DateFormatter(int firstYearInEpoch, java.lang.String inputSeparator)
Constructor which provides for alternative separator and epoch.

DateFormatter(java.lang.String inputSeparator)
Constructor which provides for an alternate string separator.

Method Summary

java.lang.String	convert(java.lang.String date) Convert a date into a four-digit year form using a default output separator.
java.lang.String	convert(java.lang.String date, java.lang.String outputSeparator) Convert a date into a four-digit year form using the output outputSeparator supplied.
protected static java.lang.String	convertMonthOrDay(java.lang.String field) Convert a month or day into a two-digit string
protected java.lang.String	convertYear(java.lang.String yearField) Convert a two- or four-digit year into a four-digit year
protected static java.util.regex.Pattern	mmddyyPattern(java.lang.String inputSeparator) Construct MM-DD-YY pattern based upon the input separator.
protected static java.util.regex.Pattern	mmyyPattern(java.lang.String inputSeparator) Construct MM-YY pattern based upon input separator
protected static java.lang.String	zeroFilled(int value, int width) Return an integer value as a string, left-filled to required width with zeroes.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

defaultSeparator

private static final java.lang.String defaultSeparator

Default string which separates input dates.

See Also:

Constant Field Values

monthDay

private static final java.lang.String monthDay

Month and day pattern: one or two digits.

See Also:

Constant Field Values

twoDigitYear

private static final java.lang.String twoDigitYear

Two-digit year pattern: exactly two digits.

See Also:

Constant Field Values

fourDigitYear

private static final java.lang.String fourDigitYear

Four-digit year pattern: exactly four digits.

See Also:

Constant Field Values

epoch

private final DateFormatter.Epoch epoch

The DateFormatter.Epoch in which to interpret two-digit years

monthDayYear

private final java.util.regex.Pattern monthDayYear

Month-day-year pattern, compiled with given input separator.

monthYear

private final java.util.regex.Pattern monthYear

Month-year pattern, compiled with given input separator.

year

private final java.util.regex.Pattern year

Year pattern: two or four digits, no separator.

Constructor Detail

DateFormatter

public DateFormatter()

Default constructor. Assume that the "/" character is a separator, and that two-digit dates fall within fifty years of today's date.

DateFormatter

public DateFormatter(java.lang.String inputSeparator)

Constructor which provides for an alternate string separator.

Parameters:

inputSeparator - String that separates days, months, and years

DateFormatter

public DateFormatter(int firstYearInEpoch,
                     java.lang.String inputSeparator)

Constructor which provides for alternative separator and epoch.

Parameters:

inputSeparator - String that separates days, months, and years

firstYearInEpoch - add to two digit years to convert to real years

Method Detail

mmddyyPattern

protected static java.util.regex.Pattern mmddyyPattern(java.lang.String inputSeparator)

Construct MM-DD-YY pattern based upon the input separator.

Parameters:

inputSeparator - input date separator character

Returns:

Pattern to match mm-dd-yy or mm-dd-yyyy

mmyyPattern

protected static java.util.regex.Pattern mmyyPattern(java.lang.String inputSeparator)

Construct MM-YY pattern based upon input separator

Parameters:

inputSeparator - input date separator character

Returns:

Pattern to match mm-yy or mm-yyyy

zeroFilled

protected static java.lang.String zeroFilled(int value,
                                             int width)

Return an integer value as a string, left-filled to required width with zeroes.

Parameters:

value - Integer value to be converted to String

width - Width of output field desired

Returns:

String form of value, left filled with zeroes to width

convertMonthOrDay

protected static java.lang.String convertMonthOrDay(java.lang.String field)

Convert a month or day into a two-digit string

Parameters:

field - value of month or day field as String

Returns:

two-digit String value with leading zeroes.

convertYear

protected java.lang.String convertYear(java.lang.String yearField)

Convert a two- or four-digit year into a four-digit year

Parameters:

yearField - year value from host application

Returns:

String four-digit year

convert

public java.lang.String convert(java.lang.String date,
                                java.lang.String outputSeparator)

Convert a date into a four-digit year form using the output outputSeparator supplied. Dates consisting of one field are assumed to be a year, two fields are a month and a year, and three fields are a month, day, and year.

Parameters:

date - date as taken from the terminal screen

outputSeparator - String used to separate result fields

Returns:

four-year date or null if invalid format

convert

public java.lang.String convert(java.lang.String date)

Convert a date into a four-digit year form using a default output separator.

Parameters:

date - date as taken from the terminal screen

Returns:

four-year date or null if invalid format