Java Reference
In-Depth Information
Listing 16.4
Manifest file for the calculator bundle
Bundle-Name: Calculator
Bundle-Description: A sample calculator bundle that registers the
calculator service
Bundle-Vendor: Apache Felix
Bundle-Version: 1.0.0
Bundle-Activator: com.manning.junitbook.ch16.CalculatorBundleActivator
Export-Package: com.manning.junitbook.ch16.service
Import-Package: org.osgi.framework
Every
OSG
i bundle is a
JAR
file, and what distinguishes the
JAR
as an
OSG
i bundle is
the
MANIFEST
.
MF
file. In the
MANIFEST
.
MF
file, we specify different kinds of metadata
for our bundle. The first few lines provide the name, description, vendor, and version
of the bundle
B
. The
Bundle-Activator
C
specifies the full name of the
Activator
class (the one that implements
BundleActivator
). As we already mentioned, a bundle
can export services. Which package is exported is specified in the
Export-Package
clause
D
. A bundle can also use and demand services; we specify which services we
use with the last clause. There we define the packages that are needed by our service
E
. You can specify multiple values separated by commas.
The final step is to compile the source code and produce the bundle (the
JAR
file).
Open a shell, navigate to the ch16-osgi\calculator-service folder, and type in the com-
mand to use Maven
B
C
D
E
mvn clean install
or the command to use Ant
ant
The result should be the same: a
JAR
file containing the classes and the
MANIFEST
.
MF
file in a
META-INF
folder.
Now that we have the bundle
JAR
that contains our service, we use the Felix con-
sole and install the bundle. Navigate to the
FELIX_HOME
directory and execute the
following command:
java -jar bin/felix.jar
You'll see the following:
Welcome to Felix.
=================
->
The Felix console is up and running, and you can now manage your services. The
first thing you can do from here is list all the services that are installed. Type in
the command
-> ps
For a complete list of all the commands you can use, type in the
help
command:
-> help
