Working with Web Services - Beginning Java 7 - page 1134

}
}
Listing 11-23 ' s ImagePublisher class describes a simple RESTful web service
whose invoke() methodhonorsonlytheHTTP GET verb.Its doGet() methodre-
spondstoa GET requestbyreturningthecontentsofthe balstone.jpg imagefileto
the client.
doGet() first instantiates the javax.activation.FileDataSource class,
whichimplements DataSource ,andwhichencapsulatesafiletobereturnedasanat-
tachment. doGet() passesthenameofthisfiletothe FileDataSource(String
name) constructor. doGet() next instantiates the
javax.activation.MimetypesFileTypeMap class so that it can associate
a MIME type with the JPEG file based on its jpg file extension. This mapping
is performed by invoking MimetypesFileTypeMap 's void ad-
dMimeTypes(String mime_types) method,passing "image/jpeg jpg" as
the argument ( image/jpeg is the MIME type and jpg is the file extension).
Continuing, doGet() invokes FileDataSource 's void
setFileTypeMap(FileTypeMap map) method to associate the Mime-
typesFileTypeMap instance with the FileDataSource instance.
After invoking FileDataSource 's String getContentType() method to
returntheMIMEtypeofthefileandoutputtingitsreturnvalue, doGet() returnsthe
FileDataSource object to invoke() , which returns this object to the JAX-WS
runtime.
I'vecreatedan ImageClient applicationtousewith ImagePublisher .Because
this application's source code is very similar to Listing 11-15 's ViewChart source
code, I won't present its code here (for brevity) — ImageClient.java is included
with this topic's source code, however.
Instead, I'll demonstrate ImagePublisher in a web browser context. Compile
ImagePublisher.java andexecutethisapplication. Oncethisapplication isrun-
ning, launch a web browser and enter http://localhost:9902/Image in its address bar.
Figure11-11 showstheresultintheMozillaFirefoxwebbrowser—youshouldalsoob-
serve image/jpeg in the ImagePublisher application's command window.