JAX-RS Content Handlers - RESTful Java with JAX-RS 2.0 - page 86

@Consumes ( "application/xml" )
public

public void void createCustomer ( Customer cust ) {

...

}

}

As you can see, once you've applied JAXB annotations to your Java classes, it is very easy
to exchange XML documents between your client and web services. The built-in JAXB
handlers will handle any JAXB-annotated class for the application/xml , text/xml , or ap-
plication/*+xml media types. By default, they will also manage the creation and initializa-
tion of JAXBContext instances. Because the creation of JAXBContext instances can be ex-
pensive, JAX-RS implementations usually cache them after they are first initialized.

Managing your own JAXBContexts with ContextResolvers
If you are already familiar with JAXB, you'll know that many times you need to configure
your JAXBContext instances a certain way to get the output you desire. The JAX-RS built-in
JAXB provider allows you to plug in your own JAXBContext instances. The way it works is
that you have to implement a factory-like interface called
javax.ws.rs.ext.ContextResolver to override the default JAXBContext creation:

public public interface interface ContextResolver ContextResolver < T > {

T getContext ( Class <?> type );

}

ContextResolvers are pluggable factories that create objects of a specific type, for a certain
Java type, and for a specific media type. To plug in your own JAXBContext , you will have to
implement this interface. Here's an example of creating a specific JAXBContext for our Cus-
tomer class:

@Provider
@Produces ( "application/xml" )
public public class class CustomerResolver CustomerResolver

implements

implements ContextResolver < JAXBContext > {

private private JAXBContext ctx ;

public public CustomerResolver () {

this this . ctx = ...; // initialize it the way you want

}

public public JAXBContext getContext ( Class <?> type ) {

iif ( type . equals ( Customer . class )) {