Chapter 2. Getting started with Weld-OSGi

2.1. Setting up your environment
2.2. Say hello to the World: your first bean bundle
2.3. CDI usage in bean bundle: a more complex example

In this chapter you will see:

how to setup the environment in order to use Weld-OSGi
how to build your first bean bundle using CDI in OSGi
how to build a more complex example with advanced CDI usage

2.1. Setting up your environment

Weld-OSGi may run in an OSGi environment, you should setup one:

Download the last version of Felix framework here: http://felix.apache.org/site/downloads.cgi
Extract the files anywhere you want, this location will be called the Felix home
Open a terminal in the Felix home and run the Felix framework with java -jar bin/felix.jar
You should now have a running OSGi environment with the Felix framework prompt:
```
____________________________
Welcome to Apache Felix Gogo

g! 
```

Try your Felix installation a bit with these three main command:

The lb command, that lists all the bundles in the OSGi environment, with their id and state (currently you only have the Felix framework utility bundles)

g! lb
START LEVEL 1
   ID|State      |Level|Name
    0|Active     |    0|System Bundle (3.2.2)
    1|Active     |    1|Apache Felix Bundle Repository (1.6.2)
    2|Active     |    1|Apache Felix Gogo Command (0.8.0)
    3|Active     |    1|Apache Felix Gogo Runtime (0.8.0)
    4|Active     |    1|Apache Felix Gogo Shell (0.8.0)
g!

The stop <bundle_id> command, that stops the corresponding bundle

g! stop 1
g! lb
START LEVEL 1
   ID|State      |Level|Name
    0|Active     |    0|System Bundle (3.2.2)
    1|Resolved   |    1|Apache Felix Bundle Repository (1.6.2)
    2|Active     |    1|Apache Felix Gogo Command (0.8.0)
    3|Active     |    1|Apache Felix Gogo Runtime (0.8.0)
    4|Active     |    1|Apache Felix Gogo Shell (0.8.0)
g!

The start <bundle_id> command, that starts the corresponding bundle

g! start 1
g! lb
START LEVEL 1
   ID|State      |Level|Name
    0|Active     |    0|System Bundle (3.2.2)
    1|Active     |    1|Apache Felix Bundle Repository (1.6.2)
    2|Active     |    1|Apache Felix Gogo Command (0.8.0)
    3|Active     |    1|Apache Felix Gogo Runtime (0.8.0)
    4|Active     |    1|Apache Felix Gogo Shell (0.8.0)
g!

Felix framework currently auto start all bundles, although it is a good thing for utility bundles it may be inconvenient with application bundles. You should configure the Felix framework by editing the Felix home conf/config.properties file:

Unable the auto start option by replacing the line

felix.auto.deploy.action=install,start

#felix.auto.deploy.action=install,start

Ask for auto start of utility bundle by replacing the line

#felix.auto.start.1=

felix.auto.start.1= file:bundle/org.apache.felix.bundlerepository-1.6.2.jar \
file:bundle/org.apache.felix.gogo.command-0.8.0.jar \
file:bundle/org.apache.felix.gogo.runtime-0.8.0.jar \
file:bundle/org.apache.felix.gogo.shell-0.8.0.jar

Install Weld-OSGi in the Felix framework:

Add some bundle in the Felix framework by simply drop the corresponding jar files into the bundle directory of Felix home
Download the last version of Weld-OSGi here: TBA
Extract the five bundles into the bundle directory of Felix home
Get Felix up to date
Felix framework keeps a cache of old bundles and actions you performed. You may remove the Felix home felix-cache directory to avoid older versions of bundle and configuration to be taken into account when:
- You add/remove bundles from bundle directory
- You modify the conf/config.properties file
- You restart the Felix framework after running some commands

Update the Felix framework configuration file in order to auto install the Weld-OSGi bundle by replacing the line

#felix.auto.install.1=

felix.auto.install.1= file:bundle/weld-osgi-core-api-1.0-SNAPSHOT.jar \
file:bundle/weld-osgi-core-extension-1.0-SNAPSHOT.jar \
file:bundle/weld-osgi-core-spi-1.0-SNAPSHOT.jar \
file:bundle/weld-osgi-core-mandatory-1.0-SNAPSHOT.jar \
file:bundle/weld-osgi-core-integration-1.0-SNAPSHOT.jar

Check the bundle are in the OSGi environment by starting the Felix framework

____________________________
Welcome to Apache Felix Gogo

g! lb
START LEVEL 1
   ID|State      |Level|Name
    0|Active     |    0|System Bundle (3.2.2)
    1|Active     |    1|Apache Felix Bundle Repository (1.6.2)
    2|Active     |    1|Apache Felix Gogo Command (0.8.0)
    3|Active     |    1|Apache Felix Gogo Runtime (0.8.0)
    4|Active     |    1|Apache Felix Gogo Shell (0.8.0)
    5|Installed  |    1|Weld-OSGi :: Core :: Extension API (1.0.0.SNAPSHOT)
    6|Installed  |    1|Weld-OSGi :: Core :: Extension Impl (1.0.0.SNAPSHOT)
    7|Installed  |    1|Weld-OSGi :: Core :: Integration API (1.0.0.SNAPSHOT)
    8|Installed  |    1|Weld-OSGi :: Core :: Mandatory (1.0.0.SNAPSHOT)
    9|Installed  |    1|Weld-OSGi :: Implementation :: Weld Integration (1.0.0.SNAPSHOT)
g!

Run the bundles Weld-OSGi :: Core :: Extension Impl and Weld-OSGi :: Implementation :: Weld Integration in order to get the Weld-OSGi running in the Felix framework

g! start 6
g! start 9
g! lb
START LEVEL 1
   ID|State      |Level|Name
    0|Active     |    0|System Bundle (3.2.2)
    1|Active     |    1|Apache Felix Bundle Repository (1.6.2)
    2|Active     |    1|Apache Felix Gogo Command (0.8.0)
    3|Active     |    1|Apache Felix Gogo Runtime (0.8.0)
    4|Active     |    1|Apache Felix Gogo Shell (0.8.0)
    5|Resolved   |    1|Weld-OSGi :: Core :: Extension API (1.0.0.SNAPSHOT)
    6|Active     |    1|Weld-OSGi :: Core :: Extension Impl (1.0.0.SNAPSHOT)
    7|Resolved   |    1|Weld-OSGi :: Core :: Integration API (1.0.0.SNAPSHOT)
    8|Resolved   |    1|Weld-OSGi :: Core :: Mandatory (1.0.0.SNAPSHOT)
    9|Active     |    1|Weld-OSGi :: Implementation :: Weld Integration (1.0.0.SNAPSHOT)
g!

It would be easier if these two bundles were auto started with Felix framework.

Modify the Felix configuration file to do so

felix.auto.install.1= file:bundle/weld-osgi-core-api-1.0-SNAPSHOT.jar \
file:bundle/weld-osgi-core-spi-1.0-SNAPSHOT.jar \
file:bundle/weld-osgi-core-mandatory-1.0-SNAPSHOT.jar
...
felix.auto.start.1= file:bundle/org.apache.felix.bundlerepository-1.6.2.jar \
file:bundle/org.apache.felix.gogo.command-0.8.0.jar \
file:bundle/org.apache.felix.gogo.runtime-0.8.0.jar \
file:bundle/org.apache.felix.gogo.shell-0.8.0.jar \
file:bundle/weld-osgi-core-extension-1.0-SNAPSHOT.jar \
file:bundle/weld-osgi-core-integration-1.0-SNAPSHOT.jar

Try this new configuration

____________________________
Welcome to Apache Felix Gogo

g! lb
START LEVEL 1
   ID|State      |Level|Name
    0|Active     |    0|System Bundle (3.2.2)
    1|Active     |    1|Apache Felix Bundle Repository (1.6.2)
    2|Active     |    1|Apache Felix Gogo Command (0.8.0)
    3|Active     |    1|Apache Felix Gogo Runtime (0.8.0)
    4|Active     |    1|Apache Felix Gogo Shell (0.8.0)
    5|Active     |    1|Weld-OSGi :: Core :: Extension Impl (1.0.0.SNAPSHOT)
    6|Active     |    1|Weld-OSGi :: Implementation :: Weld Integration (1.0.0.SNAPSHOT)
    7|Resolved   |    1|Weld-OSGi :: Core :: Extension API (1.0.0.SNAPSHOT)
    8|Resolved   |    1|Weld-OSGi :: Core :: Integration API (1.0.0.SNAPSHOT)
    9|Resolved   |    1|Weld-OSGi :: Core :: Mandatory (1.0.0.SNAPSHOT)
g!

2.2. Say hello to the World: your first bean bundle

It is time to test your installation with your first application bean bundle. The goal here is to provide a "Hello World!" (and "Goodbye World!") service and use CDI to inject it into the main class of your bean bundle. It will be the hello-world bundle.

First you need to write down the "Hello World!" service:

The com.sample.api.HelloWorld.java interface

package com.sample.api;

public interface HelloWorld {

    void sayHello();
    void sayGoodbye();
}

The com.sample.impl.HelloWorldImpl.java implementation class

package com.sample.impl;

import com.sample.api.HelloWorld;

public class HelloWorldImpl implements HelloWorld {

    @Override
    public void sayHello() {
        System.out.println("Hello World!");
    }

    @Override
    public void sayGoodbye() {
        System.out.println("Goodbye World!");
    }
}

Nothing fancy here.

Next you need to write the entry point of your application (i.e the main class of the bean bundle). That is the com.sample.App.java main class

package com.sample;

import com.sample.api.HelloWorld; (1)
import org.osgi.cdi.api.extension.events.BundleContainerEvents; (2)
import javax.enterprise.event.Observes;
import javax.inject.Inject;

public class App {

    @Inject (3)
    HelloWorld helloWorld;

    public void onStartup(@Observes BundleContainerEvents.BundleContainerInitialized event) { (4)
        helloWorld.sayHello();
    }

    public void onShutdown(@Observes BundleContainerEvents.BundleContainerShutdown event) { (5)
        helloWorld.sayGoodbye();
    }
}

You import your service interface (1) and the CDI and Weld-OSGi dependencies (2). You ask CDI for an injection of the HelloWorld service (3). onStartup method(4) and onShutdown method (5) are called when CDI usage is enable for the bean bundle (4) (i.e the bean bundle application can start) or when CDI usage is disable for the bean bundle (5) (i.e the bean bundle application may stop).

Finally you should write the configuration files of your bean bundle:

The pom.xml Maven configuration file

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.sample</groupId>
    <artifactId>hello-world</artifactId>
    <version>1.0</version>
    <packaging>bundle</packaging> (1)

    <dependencies> (2)
        <dependency>
            <groupId>javax.inject</groupId>
            <artifactId>javax.inject</artifactId>
            <version>1</version>
        </dependency>
        <dependency>
            <groupId>javax.enterprise</groupId>
            <artifactId>cdi-api</artifactId>
            <version>1.0-SP4</version>
        </dependency>
        <dependency>
            <groupId>org.osgi.cdi</groupId>
            <artifactId>weld-osgi-core-api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.felix</groupId>
                <artifactId>maven-bundle-plugin</artifactId> (3)
                <extensions>true</extensions>
                <configuration>
                    <instructions>
                        <_include>-target/classes/META-INF/${project.artifactId}.bnd</_include> (4)
                    </instructions>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

You setup the dependencies for the com.sample.App.java main class (2). You say that Maven may build an OSGi bundle (1) using the maven-bundle-plugin (3) with the META-INF/hello-world.bnd (4) configuration file.

The META-INF\beans.xml CDI marker file

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://java.sun.com/xml/ns/javaee"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/beans_1_0.xsd">
</beans>

This is an empty beans.xml file that only tells the bundle is a bean bundle (i.e Weld-OSGi may managed it).

The META-INF\hello-world.bnd OSGi configuration file
```
# Let bnd handle the MANIFEST.MF generation
```
The bnd tool will generate the OSGi MANIFEST.MF configuration file just fine for this simple example.

Your project should now looks like that:

hello-world
      pom.xml
    - src
        - main
            - java
                - com.sample
                  App.java
                    - api
                      HelloWorld.java
                    - impl
                      HelloWorldImpl.java
            - resources
                - META-INF
                  beans.xml
                  hello-world.bnd

It is time to try out this first bean bundle:

Build your project using Maven: mvn clean install
Copy the generated hello-world-1.0.jar file to the Felix home bundle directory

Update the Felix configuration file to auto install the bean bundle

felix.auto.install.1= file:bundle/weld-osgi-core-api-1.0-SNAPSHOT.jar \
file:bundle/weld-osgi-core-spi-1.0-SNAPSHOT.jar \
file:bundle/weld-osgi-core-mandatory-1.0-SNAPSHOT.jar \
file:bundle/hello-world-1.0.jar

Start the Felix framework

____________________________
Welcome to Apache Felix Gogo

g! lb
START LEVEL 1
   ID|State      |Level|Name
    0|Active     |    0|System Bundle (3.2.2)
    1|Active     |    1|Apache Felix Bundle Repository (1.6.2)
    2|Active     |    1|Apache Felix Gogo Command (0.8.0)
    3|Active     |    1|Apache Felix Gogo Runtime (0.8.0)
    4|Active     |    1|Apache Felix Gogo Shell (0.8.0)
    5|Active     |    1|Weld-OSGi :: Core :: Extension Impl (1.0.0.SNAPSHOT)
    6|Active     |    1|Weld-OSGi :: Implementation :: Weld Integration (1.0.0.SNAPSHOT)
    7|Resolved   |    1|Weld-OSGi :: Core :: Extension API (1.0.0.SNAPSHOT)
    8|Resolved   |    1|Weld-OSGi :: Core :: Integration API (1.0.0.SNAPSHOT)
    9|Resolved   |    1|Weld-OSGi :: Core :: Mandatory (1.0.0.SNAPSHOT)
   10|Installed  |    1|hello-world (1.0.0)
g!

and start your bean bundle

g! start 10
g! Hello World!

It is greeting the World ! Now stop the bean bundle

stop 10
g! Goodbye World!

and it says goodbye.

Congratulations, you just use CDI in an OSGi environment thank to Weld-OSGi. When you started your bean bundle Weld-OSGi started to manage it by providing it a Weld container. Once the container was completely started (and so the HelloWorld service injection completed) the onStartup method was called and the bean bundle application started.

2.3. CDI usage in bean bundle: a more complex example

This first bean bundle was very simple, is Weld-OSGi really enabling complex CDI usage in bean bundle? This section will pick up the hello-world example again and improve it by:

Providing three implementations of the HelloWorld service to make your bean bundle multilingual (english, french and german)
Force your bean bundle to present itself when is greeting

It will be the hello-world-multilingual bean bundle.

CDI usage limits in bean bundle

Every bean bundle gets its own Weld container from the extension bundle, so the CDI usage may stay within the bean bundle boundary:

Any bean in the bean bundle can be injected only in that bean bundle (even exported package classes)
Reciprocally, a bean from another bean bundle cannot be injected in the bean bundle (even imported package classes)
Any decorator, interceptor or alternative declaration in the beans.xml file of a bean bundle applies only for this bean bundle

Furthermore, Weld-OSGi provides Weld container to a bean bundle when it becomes active in the OSGi environment, so any bundle in another state is not managed by Weld-OSGi. And an active bean bundle has CDI usage available only after the Weld container has initialized. In the same way CDI usage is unavailable once the Weld container has shutdown. That's the reason of onStartup and onShutdown methods from previous section:

A BundleContainerEvents.BundleContainerInitialized event is fired when CDI usage gets available for the bean bundle
A BundleContainerEvents.BundleContainerShutdown event is fired when CDI usage gets unavailable for the bean bundle

These two events are CDI events and may be observed with regular CDI mechanisms.

public void onStartup(@Observes BundleContainerEvents.BundleContainerInitialized event) {
    //CDI usage are available in the bean bundle
}

public void onShutdown(@Observes BundleContainerEvents.BundleContainerShutdown event) {
    //CDI usage are unavailable in the bean bundle
}

Trying to use CDI mechanisms before the BundleContainerEvents.BundleContainerInitialized or after the BundleContainerEvents.BundleContainerShutdown event may result in errors.

First you need to upgrade your HelloWorld service and make it multilingual:

The com.sample.api.HelloWorld.java interface

package com.sample.api;

public interface HelloWorld {

    void sayHello();
    void sayGoodbye();
}

Nothing has changed here.

The com.sample.api.Language.java qualifier annotation

package com.sample.api;

import javax.inject.Qualifier;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

import static java.lang.annotation.ElementType.*;

@Qualifier (1)
@Target({ TYPE, METHOD, PARAMETER, FIELD })
@Retention(RetentionPolicy.RUNTIME)
public @interface Language {
    String value() default "ENGLISH"; (2)
}

You create a regular CDI qualifier (1) in order to choose the language of your bean bundle. The language will be choose by providing a string (ENGLISH, FRENCH or GERMAN) to the qualifier (2).

The com.sample.impl.HelloWorldImpl*.java implementation classes

package com.sample.impl;

import com.sample.api.HelloWorld;
import com.sample.api.Language;

@Language("ENGLISH") (1)
public class HelloWorldEnglish implements HelloWorld {

    @Override
    public void sayHello() {
        System.out.println("Hello World!"); (2)
    }

    @Override
    public void sayGoodbye() {
        System.out.println("Goodbye World!"); (3)
    }
}

package com.sample.impl;

import com.sample.api.HelloWorld;
import com.sample.api.Language;

@Language("FRENCH") (1)
public class HelloWorldFrench implements HelloWorld {

    @Override
    public void sayHello() {
        System.out.println("Bonjour le Monde !"); (2)
    }

    @Override
    public void sayGoodbye() {
        System.out.println("Au revoir le Monde !"); (3)
    }
}

package com.sample.impl;

import com.sample.api.HelloWorld;
import com.sample.api.Language;

@Language("GERMAN") (1)
public class HelloWorldGerman implements HelloWorld {
    
    @Override
    public void sayHello() {
        System.out.println("Hallo Welt!"); (2)
    }

    @Override
    public void sayGoodbye() {
        System.out.println("Auf Wiedersehen Welt!"); (3)
    }
}

Here you just give the language of the implementation using the Language qualifier (1), then you translate the outputs (2) (3).

Now you will use CDI interceptor to force the bean bundle to present itself every time he greets the World:

The com.sample.api.Presentation.java interceptor binding

package com.sample.api;

import javax.interceptor.InterceptorBinding;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

import static java.lang.annotation.ElementType.*;

@InterceptorBinding (1)
@Target({ TYPE, METHOD })
@Retention(RetentionPolicy.RUNTIME)
public @interface Presentation {
}

You create a regular CDI interceptor binding (1) in order to add a bean bundle presentation everytime it greets the World.

The com.sample.impl.HelloWorldImpl*.java implementation classes
```
...
public class HelloWorld* implements HelloWorld {

    @Override @Presentation (1)
    public void sayHello() {
        System.out.println("Hello World!");
    }
...
}
```
You add the interceptor binding on the sayHello method to force presentation only when the bean bundle is greeting and not saying goodbye.

The com.sample.impl.PresentationInterceptor.java interceptor

package com.sample.impl;

import com.sample.api.Presentation;

import javax.interceptor.AroundInvoke;
import javax.interceptor.Interceptor;
import javax.interceptor.InvocationContext;

@Interceptor (1)
@Presentation
public class PresentationInterceptor {

    @AroundInvoke
    public Object present(InvocationContext ctx) throws Exception {
        ctx.proceed(); (2)
        Language language = ctx.getMethod().getDeclaringClass().getAnnotation(Language.class); (3)
        if(language != null) {
            String lang = language.value();
            if(lang != null) {
                if(lang.equals("FRENCH")) {
                    System.out.println("Je suis le bundle hello-world-multilingual"); (4)
                    return null;
                } else if(lang.equals("GERMAN")) {
                    System.out.println("Ich bin das bundle hello-world-multilingual"); (5)
                    return null;
                }
            }
        }
        System.out.println("I am the bundle hello-world-multilingual"); (6)
        return null;
    }
}

The interceptor is declared so by its annotations (1). It prints the normal sentence using the intercepted method (2), then it detects the current language (3) and prints the corresponding description (4) (5) (6).

Now the HelloWorld service is a bit more complex and you use several CDI features.

Next you need to update the com.sample.App.java main class

package com.sample;

import com.sample.api.HelloWorld;
import com.sample.api.Language;
import org.osgi.cdi.api.extension.events.BundleContainerEvents;

import javax.enterprise.event.Observes;
import javax.inject.Inject;

public class App {

    @Inject @Language("ENGLISH") (1)
    HelloWorld helloWorldEnglish;

    @Inject @Language("FRENCH") (2)
    HelloWorld helloWorldFrench;

    @Inject @Language("GERMAN") (3)
    HelloWorld helloWorldGerman;

    public void onStartup(@Observes BundleContainerEvents.BundleContainerInitialized event) { (4)
        helloWorldEnglish.sayHello();
        helloWorldFrench.sayHello();
        helloWorldGerman.sayHello();
    }

    public void onShutdown(@Observes BundleContainerEvents.BundleContainerShutdown event) { (5)
        helloWorldEnglish.sayGoodbye();
        helloWorldFrench.sayGoodbye();
        helloWorldGerman.sayGoodbye();
    }
}

You replace the initial HelloWorld service injection by three qualified injection, one for each language (1) (2) (3). You also update onStartup and onShutdown methods to greet and say goodbye in the three languages (4) (5).

Finally you should write the configuration files of your bean bundle:

The pom.xml Maven configuration file

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.sample</groupId>
    <artifactId>hello-world-multilingual</artifactId>
    <version>1.0</version>
    <packaging>bundle</packaging>

    <dependencies>
        <dependency>
            <groupId>javax.inject</groupId>
            <artifactId>javax.inject</artifactId>
            <version>1</version>
        </dependency>
        <dependency>
            <groupId>javax.enterprise</groupId>
            <artifactId>cdi-api</artifactId>
            <version>1.0-SP4</version>
        </dependency>
        <dependency>
            <groupId>org.osgi.cdi</groupId>
            <artifactId>weld-osgi-core-api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.felix</groupId>
                <artifactId>maven-bundle-plugin</artifactId>
                <extensions>true</extensions>
                <configuration>
                    <instructions>
                        <_include>-target/classes/META-INF/${project.artifactId}.bnd</_include>
                    </instructions>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

Nothing has changed here, but the artifactId.

The META-INF\beans.xml CDI marker file

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://java.sun.com/xml/ns/javaee"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/beans_1_0.xsd">
    <interceptors> (1)
        <class>com.sample.impl.PresentationInterceptor</class>
    </interceptors>
</beans>

You declare your interceptor in order to activate it (1).

The META-INF\hello-world-multilingual.bnd OSGi configuration file
```
# Let bnd handle the MANIFEST.MF generation
```
Nothing has changed here.
Update bnd files name
Every time you change the artifactId of one of your bean bundle you may also update the name of its bnd file. artifactId and bnd file name should be the same in order to generate a bundle.

Your project should now looks like that:

hello-world-multilingual
      pom.xml
    - src
        - main
            - java
                - com.sample
                  App.java
                    - api
                      HelloWorld.java
                      Language.java
                      Presentation.java
                    - impl
                      HelloWorldEnglish.java
                      HelloWorldFrench.java
                      HelloWorldGerman.java
                      PresentationInterceptor.java
            - resources
                - META-INF
                  beans.xml
                  hello-world-multilingual.bnd

It is time to try out these CDI features in an OSGi environment:

Build your project using Maven: mvn clean install
Copy the generated hello-world-multilingual-1.0.jar file to the Felix home bundle directory and the remove the old hello-world-1.0.jar file.

Update the Felix configuration file to auto install the bean bundle

felix.auto.install.1= file:bundle/weld-osgi-core-api-1.0-SNAPSHOT.jar \
file:bundle/weld-osgi-core-spi-1.0-SNAPSHOT.jar \
file:bundle/weld-osgi-core-mandatory-1.0-SNAPSHOT.jar \
file:bundle/hello-world-multilingual-1.0.jar

Start the Felix framework

____________________________
Welcome to Apache Felix Gogo

g! lb
START LEVEL 1
   ID|State      |Level|Name
    0|Active     |    0|System Bundle (3.2.2)
    1|Active     |    1|Apache Felix Bundle Repository (1.6.2)
    2|Active     |    1|Apache Felix Gogo Command (0.8.0)
    3|Active     |    1|Apache Felix Gogo Runtime (0.8.0)
    4|Active     |    1|Apache Felix Gogo Shell (0.8.0)
    5|Active     |    1|Weld-OSGi :: Core :: Extension Impl (1.0.0.SNAPSHOT)
    6|Active     |    1|Weld-OSGi :: Implementation :: Weld Integration (1.0.0.SNAPSHOT)
    7|Resolved   |    1|Weld-OSGi :: Core :: Extension API (1.0.0.SNAPSHOT)
    8|Resolved   |    1|Weld-OSGi :: Core :: Integration API (1.0.0.SNAPSHOT)
    9|Resolved   |    1|Weld-OSGi :: Core :: Mandatory (1.0.0.SNAPSHOT)
   10|Installed  |    1|hello-world-multilingual (1.0.0)
g!

and start your bean bundle

g! start 10
g! Hello World!
I am the bundle hello-world-multilingual
Bonjour le Monde !
Je suis le bundle hello-world-multilingual
Hallo Welt!
Ich bin das bundle hello-world-multilingual

It is greeting the World in the three languages (and in the right order)! And it is also presenting itself. Now stop the bean bundle

stop 10
g! Goodbye World!
Au revoir le Monde !
Auf Wiedersehen Welt!

and it also says goodbye in the three languages.

CDI seems to respond perfectly in an OSGi environment, thank to Weld-OSGi. But it is sad to use only one bundle for your application, in the next chapter we will see how Weld-OSGi allow to use OSGi powerfulness coupled with CDI easiness in multi bundles application.