Building RESTful Web Services - Introducing Java EE 7 - page 121

upon. The methods that can be chained to further build the request are cookie(Cookie) ; cookie(String, String) ;
header(String, Object) ; headers(MultivaluedMap<String, Object>) ; and register .

Returning Entities
Sometimes there is a requirement to return a type other than Response from a web resource. In these cases, it is
possible to obtain an entity type by passing the entity class to the get call. The following lines of code demonstrate
how to return a Jobs entity, rather than a standard Response object:

Client client = ClientBuilder.newClient();
Jobs jobs = client.target(" http://localhost:8080/IntroToJavaEE7/rest/jobsSearch " )
.request("application/xml").get(Jobs.class);
System.out.println(jobs.getJobId() + " - " + jobs.getTitle());

In cases where entities are being returned, the request type is required to be application/xml or
APPLICATION_XML_TYPE .

Invoking at a Later Time
There are cases when it makes sense to obtain a request and prepare it for execution but not invoke that request until
a later time. In such cases, you can prepare an Invocation that can be executed at a later time. In the following lines of
code, an Invocation is created by making a request to a WebTarget and then calling the buildGet method.

Invocation inv1 = client.target(" http://localhost:8080/IntroToJavaEE7/rest/simplerest " )
.request("text/plain").buildGet();
// Sometime later...
Response res = inv1.invoke();

If you were posting a response, the buildPost method could be called against the WebTarget instead, as shown here:

Invocation inv1 = client.target(" http://localhost:8080/IntroToJavaEE7/rest/makeithappen " )
.request("text/plain").buildPost(order);
Response res = inv1.invoke();

■ Note to asynchronously execute an Invocation , call the invocation submit method, rather than the invoke method.

Invocation objects can be configured similarly to WebTarget and Client objects. Filters, interceptors, properties,
features, and providers can be configured on an Invocation by calling the register method and passing the
appropriate configuration instance, as demonstrated here:

// Assume that inv1 is an Invocation instance
String result = inv1.register(MyInterceptor.class).invoke(String.class);

■ Note to learn more about filters and interceptors, read the “filters and interceptors” section in this chapter.