Extending iBATIS - iBATIS in Action - page 275

} else if (NO.equalsIgnoreCase(s)) {
return Boolean.FALSE;
} else {
throw new IllegalArgumentException (
"Could not convert " + s +
" to a boolean value. " +
"Valid arguments are 'YES' and 'NO'.");
}
}

Converts Boolean to string

private String booleanToYesNo(Boolean b) {
if (b == null) {
throw new IllegalArgumentException (
"Could not convert null to a boolean value. " +
"Valid arguments are 'true' and 'false'.");
} else if (b.booleanValue()) {
return YES;
} else {
return NO;
}
}
}

Now that we've written our TypeHandlerCallback , we need to register it to be
used. The next section deals with that.

12.2.3 Registering a TypeHandlerCallback for use

To use a TypeHandlerCallback , we need some way to specify where and when it
should be used. There are three options:

Register it globally, in the SqlMapConfig.xml file.

■

Register it locally, within a single SqlMap.xml file.

■

Register it for a single result or parameter mapping.

■

To register the TypeHandlerCallback globally, simply add a <typeHandler> ele-
ment to your SqlMapConfig.xml . Here is the full example of the <typeHandler>
element:

<typeHandler
callback="com.domain.package.YesNoTypeHandlerCallback"
javaType="boolean" jdbcType="VARCHAR" />
The <typeHandler> element accepts two or three attributes. The first is the Type-
HandlerCallback class itself. Simply specify the fully qualified class name, or if you
like, you can also use a type alias to keep your configuration more readable. The