There’s More to Life Than Strings: Working with Data Types - Stripes...and Java Web Development is Fun Again - page 89

Primitive Type Wrapper Class Minimum Maximum

-128 127 byte Byte

-32768 32767 short Short

-2 31 2 31 - 1

int Integer

-2 63 2 63 - 1 long Long

2 −149 (2-2 −23 )×2 127

float Float

2 −1074 (2-2 −52 )×2 1023 double Double

Figure 5.2: Min and max values for number types

done at the last accepted decimal position. The input must also respect
the minimum and maximum values from Figure 5.2 .

Working with Dates
The date type converter attempts to parse the input to obtain a Date ,
with help from Java's DateFormat and a series of locale-sensitive format
patterns.

Just like the number type converters, the date type converter does some
preprocessing operations before trying to parse the input:

1. Replace all dashes ( - ), slashes ( / ), periods ( . ), and commas ( , ) with
spaces.

2. Collapse any sequences of two or more spaces to a single space.

3. If the result at this point is a string that contains two parts sepa-
rated by a space, assume that these are the day and month (or the
month and day). Since the year is required for any of the format
patterns to succeed, append a space and the current year to at
least give the input a chance of being parsed successfully.

By accepting any of - / . , as a separator but preprocessing the input
to replace the separators with spaces, the converter knows that at this
point the input is a date with the fields separated by a single space. It
becomes easy to match different date format patterns that also use a
space character as a separator, while allowing other separators in the
input.

Now that the date type converter is ready to parse the input, it tries
these date formats in order, using the first one that works.