<div class="content">

...

Declaring component types

<component
    classname="my.Implementation"
    name="my-type">
</component>

@Component(name="my-type")
public class Implementation {
  // ...
}

• How-to use iPOJO factories

Creating component instances

<instance component="my-type"/>
<instance component="my.Implementation"/>
<instance component="my-type" name="my-instance"/>
<instance component="my-type" name="my-instance">
    <property name="property1" value="value1"/>
</instance>

• Instances can contains a configuration given under the key-value form. Properties can also by complex type.
• How-to use iPOJO factories

Providing services

@Component(name="my-

type")
@Instantiate
public class Implementation {
  // ...
}

Providing services

<component classname="my.service.implementation" name="my-service-impl">
   

<provides/>
</component>
<instance name="my-service-impl"/>

@Component
@Provides
public class Implementation implements FooService {
   ...
}

• Only instances provides really services, so don't forget to declare an instance.
• Published service interfaces must be implemented by your component implementation

  ...

  Div
  class borderedTable
  Center Attribute name Required Default value   specifications no all implemented interfaces specifies the published service interfaces strategy no singleton specifies the service object creation policy among singleton, service (OSGi Service Factory), method (use the factory method), instance (an object per instance)

• Providing OSGi services

Publishing service properties

Publishing service properties

<component classname="my.service.implementation" name="my-service-impl">
  <provides>
	<property name="foo" field="m_foo" />
	<property name="bar" field="m_bar" mandatory="true" />
	<property name="baz" type="java.lang.String" /> <!-- Static property (do not change at runtime) -->
  </provides>
</component>
<instance name="my-service-impl"> <!-- The configuration has to inject value in unvalued mandatory properties -->
  <property name="bar" value="5"/>
  <property name="baz" value="my string"/>
<instance/>

• Providing OSGi services

Using services with field injection

• Service Requirement Handler

@Component
@Provides(specifications= {FooService.class, BarService.class}

,

properties= {
	@StaticServiceProperty(name="baz", type="java.lang.String")})
public class ProvidesProperties implements FooService, BarService {
    
    @ServiceProperty(name = "foo")
    public int m_foo = 0;
    
    @ServiceProperty(name="bar", mandatory=true)
    public int m_bar;
    
// ...
}

<component classname="my.consumer.Implementation">
    <requires field="fs" />
</component>

@Component
public class Dependency {

    @Requires
    public FooService fs;
    
    //...
}

• Providing OSGi services

Using services with field injection

<component classname="my.consumer.Implementation">
    

<requires field="

fs" 

/>

    <requires field="bs" />

</

component>

@Component
public class Dependency {

    

@Requires
    public 

FooService fs;

    

@Requires
    

public 

BarService[] bs;
   

//...
}

• Service Requirement Handler

Using services with method injection

Lifecycle callbacks

<callback type="modified" method="modified" 

/> <!-- for filtered service dependencies, to be notified when a service is modified but still match -->
    

• Lifecycle Callback Handler

</requires>	
</component>

<component classname="my.consumer.Implementation">
    <requires>
	<callback type="bind" method="bind" />
	<callback type="unbind" method="unbind" />

<component classname="my.service.implementation" name="my-service-impl" immediate="true">
   <provides/>
</component>

@Component(immediate=true)
@Provides
public class Implementation implements FooService {
   ...
}

<component classname="my.implementation" name="my-impl">
    <callback transition="validate" method="start" />
    <callback transition="invalidate" method="stop" />
</component>

public synchronized void bindBaz(BazService bz) {
        // ...
    }

    @Modified
    public synchronized void modifiedBaz() {
        // ...
    }

• Configuration Handler

Using 'arch'

• Deploy the 'arch' command bundle (available for Felix and Equinox)
• Launch the 'arch' command in the OSGi Framework Shell

@Component
public class Dependency {

    

@Unbind
    public synchronized void unbindBaz(BazService bz) {
        //...
    

}
    
    @Bind
    

arch => displays instances name & state (equivalent to arch \-instances)
arch -instance $instance_name => displays complete information about the instance $instance_name
arch -factories => display the list of available factories
arch -factory $factory_name => display complete information about the factory $factory_name
arch -handlers => list available handlers

Temporal Dependencies

• Temporal dependencies are injected in fields. When accessing to the service, the thread waits for the service availability. If a timeout is reached, a timeout policy is executed.
• Service objects can be injected as proxies and be given to collaborator objects.
• Temporal dependencies are implemented as an external handlers. To use them, deploy and start the temporal dependency handler bundle.

<iPOJO xmlns:temporal="org.apache.felix.ipojo.handler.temporal">
<component
    className="my.Implementation">

    <!-- Temporal dependency configuration -->
    <temporal:requires field="mytemporal"/>
    <provides/>
</component>
</iPOJO>

import org.apache.felix.ipojo.annotations.Component;
import org.apache.felix.ipojo.handler.temporal.Requires;
import org.apache.felix.ipojo.test.scenarios.annotations.service.FooService;

@Component
public class Implementation {
    
    @Requires // org.apache.felix.ipojo.handler.temporal.Requires
    private FooService mytemporal;
    
}

• Temporal Service Dependency

Sending and receiving events

Receiving events

//...
}

• Service Requirement Handler

Configuring service dependencies in the instance configuration

Configuring the from attribute

• Thanks to the requires.from property, it is possible to override the from attribute value.

<component 
   classname="...MyComponent"
   name="FOO">
	<requires field="m_foo" id="id1">
		<callback type="bind" method="bind"/>
		<callback type="unbind" method="unbind"/>
	</requires>
</component>

<instance name="FOO1" component="FOO"/> <!-- Use the default 'from' value -->

<instance name="FOO2" component="FOO">
	<property name="requires.from">
		<property name="id1" value="myprovider"/>
	</property>
</instance>

Configuring the filter attribute

• Thanks to the requires.filters property, it is possible to override the filter attribute value.

• Instance configuration
  • event.topics : overrides topics attribute
  • event.filter : overrides filter attribute

• Event Admin Handlers

Sending events

• The event admin handler allows sending events to the Event Admin.
• The event admin handler is implemented as an external handlers. To use it, deploy and start the event admin handler bundle and an implementation of the event admin service.
• To send events, your code must contains a org.apache.felix.ipojo.handlers.event.publisher.Publisher field.

• Event Admin Handlers

• Instance configuration
  • event.topics : overrides topics attribute

Extender Pattern

• Allows implementing an Extender pattern without handling obscure details
• The extender pattern handler is implemented as an external handlers. To use it, deploy and start the external pattern handler bundle.

• Extender Pattern Handler

Whiteboard Pattern

• Allows implementing a Whiteboard pattern without handling obscure details
• The whiteboard pattern handler is implemented as an external handlers. To use it, deploy and start the whiteboard pattern handler bundle.

component>

<instance name="FOO1" component="FOO"/> <!-- Use the default 'filter' value -->

<instance name="FOO2" component="FOO">
	<property name="requires.filters">
		<property name="id1" value="(foo.property=BAR)"/>
	</property>
</instance>

<component 
   

classname="org.apache.felix.ipojo.

example.FilteredDependency" 
   name="FOO">
	

<requires field="m_foo" fiter="

(foo.property=FOO)" id="id1">
		<callback type="bind" method="bind"/>
		<callback type="unbind" method="unbind"/>
	</

requires>
</

@Component
public class MyComponent {
    
    @Subscriber(name="s1", data_key="data")
    public void receive1(Object foo) {
        // Nothing
    }
    
    @Subscriber(name="s2", topics="foo,bar", filter="(foo=true)")
    public void receive2(Event foo) {
        // Nothing
    }
    
    
    @Subscriber(name="s3", topics="foo", data_key="data", data_type="java.lang.String")
    public void receive3(String foo) {
        // Nothing
    }

<instance component="...MyComponent">
		<property name="event.topics">
			<property name="mySubscriber" value="foo"/>
		</property>
		<property name="event.filter">
			<property name="mySubscriber"
				    value="|((arg=Minibar)(arg=Coconuts))"/>
		</property>
	</instance>

<ipojo
    xmlns:ev="org.apache.felix.ipojo.handlers.event.EventAdminHandler">
	<component className="...MyComponent">
		<ev:publisher
			name="myPublisher"
			field="m_publisher"
			topics="bar,nuts"/>
	</component>
	<instance component="...MyComponent"/>
</ipojo>

@Component
public class MyComponent {
    @org.apache.felix.ipojo.handlers.event.Publisher(name="p1", synchronous=true)
    org.apache.felix.ipojo.handlers.event.publisher.Publisher publisher1;
    
    @org.apache.felix.ipojo.handlers.event.Publisher(name="p2", synchronous=false, topics="foo,bar", data_key="data")
    org.apache.felix.ipojo.handlers.event.publisher.Publisher publisher2;
    
    @org.apache.felix.ipojo.handlers.event.Publisher(name="p3", synchronous=true, topics="bar")
    org.apache.felix.ipojo.handlers.event.publisher.Publisher publisher3;

    // ...

    public void doSomething() {
        Dictionary e = new Properties();
        //...
        // Fill out the event

        // Send event
        publisher1.send(e);
    }
}

<instance component="...MyComponent">
		<property name="event.topics">
			<property name="myPublisher" value="foo"/>
		</property>
	</instance>

<ipojo xmlns:extender="org.apache.felix.ipojo.extender">
	<component
		classname="org.apache.felix.ipojo.extender.Myextender">
		
                <!—Extender Pattern handler configuration -->
		<extender:extender 
                  extension="My-Extension"
                  onArrival="onArrival" 
                  onDeparture="onDeparture" 
                />

		<callback transition="invalidate" method="stopping" />
		<callback transition="validate" method="starting" />
	</component>
</ipojo>

@Component
@org.apache.felix.ipojo.extender.Extender(extension="My-Extension", onArrival="onArrival", onDeparture="onDeparture")
public class Myextender {
    
    public void onArrival(Bundle bundle, String extension) {
        // handle matching bundle arrival
    }
    
    public void onDeparture(Bundle bundle) {
        // handler matching bundle departure
    }
}

Reacting to lifecycle state changes

Immediate components

• A POJO object (implementation object) is created as soons as the instance becomes valid
• Instances that don't provide services becomes automatically immediate

  Code Block
  xml xml title XML
  <component classname="my.service.implementation" name="my-service-impl" immediate="true"> <provides/> </component>

  Code Block
  java java title Annotations
  @Component(immediate=true) @Provides public class Implementation implements FooService { ... }

  Div
  class borderedTable
  Center Attribute name Required Default value   immediate no false // true for instances that don't provide a service specifies if the instance is immediate or not

• Lifecycle Callback Handler

Lifecycle callbacks

<component classname="my.implementation" name="my-impl">
    <callback transition="validate" method="start" />
    <callback transition="invalidate" method="stop" />
</component>

@Component
public class Implementation {
    
    @Validate
    public void start() {
        
    }
    
    @Invalidate
    public void stop() {
        
    }
}

• Lifecycle Callback Handler

Declaring properties

<component classname="my.Implementation" name="my-impl">
    <properties propagation="true" managedservice="MyPID">
        <property name="boo" method="setBoo" />
	<property field="m_bar" mandatory="true"/>
	<property field="m_foo" value="4"/>
    </properties>
</component>
<instance component="my-impl">
    <property name="boo" value="..."/>
    <property name="m_bar" value="..."/>
</instance>
<instance component="my-impl">
    <property name="boo" value="..."/>
    <property name="m_bar" value="..."/>
    <property name="managed.service.pid" value="AnotherPID"/>
</instance>

@Component(managedservice="MyPID", propagation=true)
public class Implementation {
    
    @Property(name="boo")
    public void setBoo(int boo) {
        //...
    }
        
    @Property(mandatory=true)
    public int m_bar;

    @Property(value="4")
    public int m_foo;
}

• Configuration Handler

PostRegistration and PostUnregistration callbacks

• This feature is part of the provided service handler, and so requires that the component provides a service.
• The callback receives a ServiceReference as parameter.

  Code Block
  xml xml title XML
  <component classname="..."> <provides post-unregistration="unregistered" post-registration="registered"/> </component>

  Code Block
  java java title Annotations
  @PostRegistration public void registered(ServiceReference ref) { System.out.println("Registered"); } @PostUnregistration public void unregistered(ServiceReference ref) { System.out.println("Unregistered"); }

• Provided Service Handler

Controlling service publication

• This feature is part of the provided service handler, and so requires that the component provides a service.
• It allows a component to force the un-publication of a service.

  Code Block
  xml xml title XML
  <component classname="..."> <provides> <controller field="controller" value="false"/> </provides> </component>

  Code Block
  java java title Annotations
  @ServiceController(value="false") private boolean controller

• Provided Service Handler

Using 'arch'

• Deploy the 'arch' command bundle (available for Felix and Equinox)
• Launch the 'arch' command in the OSGi Framework Shell

  Code Block
  java java title Felix Shell
  arch => displays instances name & state (equivalent to arch \-instances) arch -instance $instance_name => displays complete information about the instance $instance_name arch -factories => display the list of available factories arch -factory $factory_name => display complete information about the factory $factory_name arch -handlers => list available handlers

  Code Block
  java java title Felix Gogo
  ipojo:instances => displays instances name & state (equivalent to arch \-instances) ipojo:instance $instance_name => displays complete information about the instance $instance_name ipojo:factories => display the list of available factories ipojo:factory $factory_name => display complete information about the factory $factory_name ipojo:handlers => list available handlers

• iPOJO Arch Command
• Architecture Handler

Temporal Dependencies

• Temporal dependencies are injected in fields. When accessing to the service, the thread waits for the service availability. If a timeout is reached, a timeout policy is executed.
• Service objects can be injected as proxies and be given to collaborator objects.
• Temporal dependencies are implemented as an external handlers. To use them, deploy and start the temporal dependency handler bundle.

<iPOJO xmlns:temporal="org.apache.felix.ipojo.handler.temporal">
<component
    className="my.Implementation">

    <!-- Temporal dependency configuration -->
    <temporal:requires field="mytemporal"/>
    <provides/>
</component>
</iPOJO>

import org.apache.felix.ipojo.annotations.Component;
import org.apache.felix.ipojo.handler.temporal.Requires;
import org.apache.felix.ipojo.test.scenarios.annotations.service.FooService;

@Component
public class Implementation {
    
    @Requires // org.apache.felix.ipojo.handler.temporal.Requires
    private FooService mytemporal;
    
}

• Temporal Service Dependency

Sending and receiving events

Receiving events

• The event admin handler allows receiving events from the Event Admin.
• The event admin handler is implemented as an external handlers. To use it, deploy and start the event admin handler bundle and an implementation of the event admin service.
• Event (or data) are receive thanks to a callback method.

<ipojo
    xmlns:ev="org.apache.felix.ipojo.handlers.event.EventAdminHandler">
	<component className="...MyComponent">
		<ev:subscriber
			name="mySubscriber"
			callback="receive"
			topics="foo"/>
	</component>
</ipojo>

@Component
public class MyComponent {
    
    @Subscriber(name="s1", data_key="data")
    public void receive1(Object foo) {
        // Nothing
    }
    
    @Subscriber(name="s2", topics="foo,bar", filter="(foo=true)")
    public void receive2(Event foo) {
        // Nothing
    }
    
    
    @Subscriber(name="s3", topics="foo", data_key="data", data_type="java.lang.String")
    public void receive3(String foo) {
        // Nothing
    }

• Instance configuration
  • event.topics : overrides topics attribute
  • event.filter : overrides filter attribute

<instance component="...MyComponent">
		<property name="event.topics">
			<property name="mySubscriber" value="foo"/>
		</property>
		<property name="event.filter">
			<property name="mySubscriber"
				    value="|((arg=Minibar)(arg=Coconuts))"/>
		</property>
	</instance>

• Event Admin Handlers

Sending events

• The event admin handler allows sending events to the Event Admin.
• The event admin handler is implemented as an external handlers. To use it, deploy and start the event admin handler bundle and an implementation of the event admin service.
• To send events, your code must contains a org.apache.felix.ipojo.handlers.event.publisher.Publisher field.

<ipojo
    xmlns:ev="org.apache.felix.ipojo.handlers.event.EventAdminHandler">
	<component className="...MyComponent">
		<ev:publisher
			name="myPublisher"
			field="m_publisher"
			topics="bar,nuts"/>
	</component>
	<instance component="...MyComponent"/>
</ipojo>

@Component
public class MyComponent {
    // We use qualified names to avoid conflict.
    @org.apache.felix.ipojo.handlers.event.Publisher(name="p1", synchronous=true)
    org.apache.felix.ipojo.handlers.event.publisher.Publisher publisher1;
    
    @org.apache.felix.ipojo.handlers.event.Publisher(name="p2", synchronous=false, topics="foo,bar", data_key="data")
    org.apache.felix.ipojo.handlers.event.publisher.Publisher publisher2;
    
    @org.apache.felix.ipojo.handlers.event.Publisher(name="p3", synchronous=true, topics="bar")
    org.apache.felix.ipojo.handlers.event.publisher.Publisher publisher3;

    // ...

    public void doSomething() {
        Dictionary e = new Properties();
        //...
        // Fill out the event

        // Send event
        publisher1.send(e);
    }
}

• Event Admin Handlers

• Instance configuration
  • event.topics : overrides topics attribute

<instance component="...MyComponent">
		<property name="event.topics">
			<property name="myPublisher" value="foo"/>
		</property>
	</instance>

Extender Pattern

• Allows implementing an Extender pattern without handling obscure details
• The extender pattern handler is implemented as an external handlers. To use it, deploy and start the external pattern handler bundle.

<ipojo xmlns:extender="org.apache.felix.ipojo.extender">
	<component
		classname="org.apache.felix.ipojo.extender.Myextender">
		
                <!—Extender Pattern handler configuration -->
		<extender:extender 
                  extension="My-Extension"
                  onArrival="onArrival" 
                  onDeparture="onDeparture" 
                />

		<callback transition="invalidate" method="stopping" />
		<callback transition="validate" method="starting" />
	</component>
</ipojo>

@Component
@org.apache.felix.ipojo.extender.Extender(extension="My-Extension", onArrival="onArrival", onDeparture="onDeparture")
public class Myextender {
    
    public void onArrival(Bundle bundle, String extension) {
        // handle matching bundle arrival
    }
    
    public void onDeparture(Bundle bundle) {
        // handler matching bundle departure
    }
}

• Extender Pattern Handler

Whiteboard Pattern

• Allows implementing a Whiteboard pattern without handling obscure details
• The whiteboard pattern handler is implemented as an external handlers. To use it, deploy and start the whiteboard pattern handler bundle.

<ipojo xmlns:wbp="org.apache.felix.ipojo.whiteboard">
     <component 
          classname="org.apache.felix.ipojo.test.MyWhiteBoardPattern"
      >
        <wbp:wbp 
   	      filter="(my.property=1)" 
              onArrival="onArrival" 
              onDeparture="onDeparture" 
              onModification="onModification"
         />
       
         <provides/>
      </component>

void onArrival(ServiceReference ref) {
        

// ...
    }
 
    public 

void onDeparture(ServiceReference ref) {
        

// ...
    }
    
    public void 

onModification(ServiceReference ref) {
        // 

...
    }

• White Board Pattern Handler

}

@Component
@org.apache.felix.ipojo.whiteboard.Wbp(

filter="(my.property=1)", 
        

onArrival="onArrival", 

onDeparture="onDeparture"

,
        

onModification="onModification")
public class 

WhiteBoardWIModification {
    

    public 

• White Board Pattern Handler
  
  

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