There’s More to Life Than Strings: Working with Data Types - Stripes...and Java Web Development is Fun Again - page 92

Single Characters
Last (and perhaps least) of the built-in type converters is the character
type converter. It just takes the first character in the input String to
produce a char or a Character . So, "Hello" will be converted to 'H' .
Other Provided Type Converters
The type converters we've seen so far are used automatically. Stripes
also provides a few other type converters that do the conversion only if
we specifically tell Stripes to use them. These additional type converters
are as follows:
• EmailTypeConverter
• CreditCardTypeConverter
• PercentageTypeConverter
• OneToManyTypeConverter
To indicate we want one of these type converters to convert the input
for a given property, we annotate the property with @Validate(converter=
TheTypeConverter.class) . For example:
// Use EmailTypeConverter for this property
@Validate(converter=EmailTypeConverter. class )
public String email;
We saw EmailTypeConverter in Section 4.2 , Email Addresses, on page 78
and CreditCardTypeConverter in Section 4.2 , Credit Card Numbers, on
page 86 . Let us now look at PercentageTypeConverter and OneToMany-
TypeConverter .
PercentageTypeConverter
PercentageTypeConverter works on a property of decimal type: float , Float ,
double , Double , or BigDecimal . The input string is considered as a per-
centage, with or without a percent symbol (%). The numerical result is
the value of the input divided by 100 .
PercentageTypeConverter preprocesses the input just like the other deci-
mal type converters. For example, it accepts all these inputs to produce
the corresponding results, as we can see in the table on the next page.