Java Reference
In-Depth Information
duces
annotation so that the JAX-RS implementation knows how to set the
Content-Type
header.
java.io.File
Instances of
java.io.File
can also be used for input and output of any media type. Here's
an example for returning a reference to a file on disk:
@Path
(
"/file"
)
public
public class
class
FileService
FileService
{
private
private static
static final
final
String basePath
=
"..."
;
@GET
@Path
(
"{filepath: .*}"
)
@Produces
(
"text/plain"
)
public
public
File
getFile
(
@PathParam
(
"filepath"
)
String path
) {
return
return new
new
File
(
basePath
+
path
);
}
In this example, we're using an injected
@PathParam
to create a reference to a real file that
exists on our disk. We create a
java.io.File
based on this path and return it as our re-
sponse body. The JAX-RS implementation will open up an
InputStream
based on this file
reference and stream into a buffer that is written back incrementally to the response's output
stream. We must specify the
@Produces
annotation so that the JAX-RS implementation
knows how to set the
Content-Type
header.
You can also inject
java.io.File
instances that represent the incoming request response
body. For example:
@POST
@Path
(
"/morestuff"
)
public
public
void
void
post
(
File file
) {
Reader reader
=
new
new
FileInputStream
(
file
));
LineNumberReader lineReader
=
new
new
Reader
(
new
new
LineNumberReader
(
reader
);
ddo
{
String line
=
lineReader
.
readLine
();
iif
(
line
!=
null
null
)
System
.
out
.
println
(
line
);
}
while
while
(
line
!=
null
null
);
}
The way this works is that the JAX-RS implementation creates a temporary file for input on
disk. It reads from the network buffer and saves the bytes read into this temporary file. In our
example, we create a
java.io.FileInputStream
from the
java.io.File
object that was
