Getting Startedwith pureQuery

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Getting Started with pureQuery
// Close employees. This frees the associated database resources.
if (null != employees) ((ResultIterator) employees).close
();
}
Listing 13.4 - Close employees. This frees the database resources if an exception
occurs before the application retrieves all of the rows.
Finally, test the application.
13.3 Specifying handlers in the annotated method style
When you use the annotated-method style, you can specify handlers for customizing the
input and output of your annotated methods.
When you specify handlers for annotated methods, make sure that the return type of your
method is compatible with your handler. The Java compiler is not able to recognize if the
type of a handler is not compatible with the return type of the method. If the type is not
compatible, you will not know there is a problem until you generate an implementation
class for your interface and observe that it does not compile.
The annotated-method style provides two ways of specifying handlers. You can specify
handlers either in the com.ibm.pdq.annotation.Handler annotation, or as
parameters to the annotated methods. For an annotated method, you can specify at most
one handler that customizes output for each annotated method. You can also specify the
ParameterHandler, which customizes input, if you want.
13.3.1 Specifying handlers by using the @Handler annotation
pureQuery provides the annotation com.ibm.pdq.annotation.Handler, which you
can add to annotated methods to indicate the handlers that you want them to use. The
annotation contains an element for each type of handler. To specify that you want to use a
specific handler, set the appropriate annotation element to the class of the handler that you
want to use.
Listing 13.5 shows an example of specifying the JSONResultHandler for an annotated
method. Note that the return type of the annotated method is String because the
handle method of the JSONResultHandler has a return type of String.
@Handler(resultHandler=JSONResultHandler.class)
@Select(sql = "SELECT * FROM EMPLOYEE ORDER BY LASTNAME, FIRSTNME,
MIDINIT")
String selectAllEmployees ();
Listing 13.5 - An example of using the @Handler annotation to specify a handler
When you specify a handler with the @Handler annotation, the handler must have a public
no-argument constructor. pureQuery creates an instance of the handler by using that