Java Reference
In-Depth Information
chooseaviewer—youwillalsoobservethisMIMEtypein
ImagePublisher
'scom-
mand window.
The reason for this change of MIME type has to do with
Mime-
typesFileTypeMap
's
String getContentType(String filename)
method.Atsomepoint,thismethodiscalledtoreturnthecontenttypeforthespecified
filename. When this name is missing an extension, or when a MIME type for the
file's extension has not been registered (via a call to
addMimeTypes()
),
getCon-
tentType()
returns the default
application/octet-stream
MIME type.
Youmightwanttokeepthisscenarioinmindwhencustomizing
ImagePublisher
(andaclient)toworkwiththeHTTP
Accept
requestheader.(Theclientspecifiesan
Accept
header[via
URLConnection
's
void setRequestProperty(String
key, String value)
method]withoneormoreMIMEtypesthattelltheserver
whatkind(s)ofdatatheclientwantstoreceive;theserverexaminesthisheaderandre-
turns this data when the header includes a MIME type that the server can honor.)
Note
If you're wondering why
@ServiceMode(value =
javax.xml.ws.Service.Mode.MESSAGE)
is specified in
Listing 11-23
,
the
answer is that
Provider<DataSource>
is used for sending attachments, which
means that
javax.xml.ws.Service.Mode.PAYLOAD
mode is invalid.
Providers and Dispatch Clients
This chapter presents high-level and low-level approaches to working with JAX-WS.
The high-level approach requires you to work with SEIs and SIBs; it simplifies and
hidesthedetailsofconvertingbetweenJavamethodinvocationsandtheircorresponding
SOAP-basedXMLmessages.Thelow-levelapproachletsyouworkdirectlywithXML
messages, and must be followed to implement a RESTful web service.
While discussing how to implement a RESTful web service with JAX-WS, I intro-
ducedyoutothisAPI's
Provider<T>
interface,whose
invoke()
methodiscalled
byaclienttoreceiveandprocessarequest,andtoreturnaresponse.Ithendemonstrated
howaclientcommunicateswithaproviderbyusingthe
HttpURLConnection
class.
Behindthescenes,theJAX-WSruntimetakestheinformationreceivedfromtheURL
connectionandcreatestheproperobjecttopassto
invoke()
.Italsotakestheobject
returned from
invoke()
and makes its contents available to the client via the URL
connection's output stream.
JAX-WSalsooffersthe
javax.xml.ws.Dispatch<T>
interfaceasaclient-side
companionto
Provider
.Aclientuses
Dispatch
toconstructmessagesormessage
