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Declaring component types

Code Block
xml
xml
titleXMLxml
<component
    classname="my.Implementation"
    name="my-type">
</component>
Code Block
java
java
titleAnnotationsjava
@Component(name="my-type")
public class Implementation {
  // ...
}
Wiki Markup
{div:class=borderedTable}
{center}
||Attribute name || Required || Default value || ||
| classname | yes | | indicates the implementation class (automatic when using annotations). |
| name | no | implementation class name | specifies the component type name. |
| public \\ (public_factory for annotations) | no | true | specifies if the component type is accessible from others bundle or is private.|
| factory-method \\ (factory_method for annotations) | no |  | specifies a static method to call instead of the 'regular' constructor to create POJO objects.|
{center}
{div}
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classborderedTable
Center

Attribute name

Required

Default value

 

classname

yes

 

indicates the implementation class (automatic when using annotations).

name

no

implementation class name

specifies the component type name.

public
(public_factory for annotations)

no

true

specifies if the component type is accessible from others bundle or is private.

factory-method
(factory_method for annotations)

no

 

specifies a static method to call instead of the 'regular' constructor to create POJO objects.

Creating component instances

Code Block
xml
xml
titleXMLxml
<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>
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classborderedTable
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Attribute name

Required

Default value

 

component

yes

 

specifies the component type (either by using the name or the class name)

name

no

generated

specifies the instance name.

Wiki Markup
{div:class=borderedTable} {center} ||Attribute name || Required || Default value || || | component | yes | | specifies the component type (either by using the name or the class name) | | name | no | generated | specifies the instance name. | {center} {div}

  • Instances can contains a configuration given under the key-value form. Properties can also by complex type.
  • How-to use iPOJO factories
Code Block
java
java
titleAnnotationsjava
@Component(name="my-type")
@Instantiate
public class Implementation {
  // ...
}

Providing services

Code Block
xml
xml
titleXMLxml
<component classname="my.service.implementation" name="my-service-impl">
   <provides/>
</component>
<instance name="my-service-impl"/>
Code Block
java
java
titleAnnotationsjava
@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
    Wiki Markup
    Div
    classborderedTable
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    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)

    {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) | {center} {div}

  • Providing OSGi services

Publishing service properties

Code Block
xml
xml
titleXMLxml
<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/>
Code Block
java
java
titleAnnotationsjava
@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;
    
// ...
}
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Attribute name

Required

Default value

 

name

no

field name

specifies the published property name

mandatory

no

false

specifies if the property has to receive a value from the instance configuration

value

no

 

specifies the default property value

field

no

(automatic with annotations)

specifies the field attached to the service property

type

Only if there is no field (generated)

Type of the property

Wiki Markup
{div:class=borderedTable} {center} ||Attribute name || Required || Default value || || | name | no | field name | specifies the published property name | | mandatory | no | false | specifies if the property has to receive a value from the instance configuration | | value | no | | specifies the default property value | | field | no | (automatic with annotations) | specifies the field attached to the service property | | type | Only if there is no field (generated) | Type of the property | {center} {div}

Using services with field injection

Code Block
xml
xml
titleXMLxml
<component classname="my.consumer.Implementation">
    <requires field="fs" />
    <requires field="bs" />
</component>
Code Block
java
java
titleAnnotationsjava
@Component
public class Dependency {

    @Requires
    public FooService fs;

    @Requires
    public BarService[] bs;
    
    //...
}
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Attribute name

Required

Default value

 

id

no

field name

dependency id

field

no

automatically detected with annotations

injected field

optional

no

false

specifies if the dependency if optional

aggregate

no

false
(automatically detected with fields)

specifies if the dependency is aggregate of scalar

specification

yes/no

can be discovered from the code

specifies the required service specification. This attribute is required when the service type cannot be inferred from the code (Collection type for fields, callbacks without service objects)

filter

no

no filter

specifies the dependency LDAP filter

from

no

 

specifies a specific provider by its name

policy

no

dynamic

specifies the binding policy among dynamic, static and dynamic-priority

nullable

no

true

enables/disables nullable object injection for optional dependencies

default-implementation // defaultimplementation for annotations

no

 

specifies the default-implementation for optional dependencies

comparator

no

 

specifies the comparator class used to sort service providers

Wiki Markup
{div:class=borderedTable} {center} ||Attribute name || Required || Default value || || | id | no | field name | dependency id | | field | no | automatically detected with annotations | injected field | | optional | no | false | specifies if the dependency if optional | | aggregate | no | false \\ (automatically detected with fields) | specifies if the dependency is aggregate of {{scalar}} | | specification | yes/no | can be discovered from the code | specifies the required service specification. This attribute is required when the service type cannot be inferred from the code (Collection type for fields, callbacks without service objects) | | filter | no | no filter | specifies the dependency LDAP filter | | from | no | | specifies a specific provider by its name | | policy | no | {{dynamic}} | specifies the binding policy among {{dynamic}}, {{static}} and {{dynamic-priority}} | | nullable | no | true | enables/disables nullable object injection for optional dependencies | | default-implementation // defaultimplementation for annotations | no | | specifies the default-implementation for optional dependencies | | comparator | no | | specifies the comparator class used to sort service providers | {center} {div}

Using services with method injection

Code Block
xml
xml
titleXMLxml
<component classname="my.consumer.Implementation">
    <requires>
	<callback type="bind" method="bind" />
	<callback type="unbind" method="unbind" />
        <callback type="modified" method="modified" /> <!-- for filtered service dependencies, to be notified when a service is modified but still match -->
    </requires>	
</component>
Code Block
java
java
titleAnnotationsjava
@Component
public class Dependency {

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

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

  //...
}
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Attribute name

Required

Default value

 

id

no

field name

dependency id

field

no

automatically detected with annotations

injected field

optional

no

false

specifies if the dependency if optional

aggregate

no

false
(automatically detected with fields)

specifies if the dependnency is aggregate of scalar

specification

yes/no

can be discovered from the code

specifies the required service specification. This attribute is required when the service type cannot be infered from the code (Collection type for fields, callbacks without service objects)

filter

no

no filter

specifies the dependency LDAP filter

from

no

 

specifies a specific provider by its name

policy

no

dynamic

specifies the binding policy among dynamic, static and dynamic-priority

nullable

no

true

enables/disables nullable object injection for optional dependencies

default-implementation // default implementation for annotations

no

 

specifies the default-implementation for optional dependencies

comparator

no

 

specifies the comparator class used to sort service providers

Sub-Element name

Required

Default value

 

callback

no

callback specifies bind and unbind method. Two attributes are required (discovered automatically with annotations). type specified if the callback is a bind or unbind method (among {bind, unbind, modified}. The method attribute specified the method to call. The modified callback is called when the service properties of a bound service are modified and the service still match the filter.

Wiki Markup
{div:class=borderedTable} {center} ||Attribute name || Required || Default value || || | id | no | field name | dependency id | | field | no | automatically detected with annotations | injected field | | optional | no | false | specifies if the dependency if optional | | aggregate | no | false \\ (automatically detected with fields) | specifies if the dependnency is aggregate of {{scalar}} | | specification | yes/no | can be discovered from the code | specifies the required service specification. This attribute is required when the service type cannot be infered from the code (Collection type for fields, callbacks without service objects) | | filter | no | no filter | specifies the dependency LDAP filter | | from | no | | specifies a specific provider by its name | | policy | no | {{dynamic}} | specifies the binding policy among {{dynamic}}, {{static}} and {{dynamic-priority}} | | nullable | no | true | enables/disables nullable object injection for optional dependencies | | default-implementation // default implementation for annotations | no | | specifies the default-implementation for optional dependencies | | comparator | no | | specifies the comparator class used to sort service providers | || Sub-Element name || Required || Default value || || | callback | no | callback specifies bind and unbind method. Two attributes are required (discovered automatically with annotations). {{type}} specified if the callback is a bind or unbind method (among \{{{bind}}, {{unbind}}, {{modified}}\}. The {{method}} attribute specified the method to call. The {{modified}} callback is called when the service properties of a bound service are modified and the service still match the filter. {center} {div}

...

  • Thanks to the requires.from property, it is possible to override the from attribute value.
Code Block
xml
xml
1From attribute configurationxml
<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>

...

  • Thanks to the requires.filters property, it is possible to override the filter attribute value.
Code Block
xml
xml
1Filter attribute configurationxml
<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>

<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>

...

  • 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
    titleXMLxml
    <component classname="my.service.implementation" name="my-service-impl" immediate="true">
       <provides/>
    </component>
    
    Code Block
    java
    java
    titleAnnotationsjava
    @Component(immediate=true)
    @Provides
    public class Implementation implements FooService {
       ...
    }
    
    }
    
    Div
    classborderedTable
    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

    Wiki Markup
    {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 | {center} {div}

  • Lifecycle Callback Handler

Lifecycle callbacks

Code Block
xml
xml
titleXMLxml
<component classname="my.implementation" name="my-impl">
    <callback transition="validate" method="start" />
    <callback transition="invalidate" method="stop" />
</component>
Code Block
java
java
titleAnnotationsjava
@Component
public class Implementation {
    
    @Validate
    public void start() {
        
    }
    
    @Invalidate
    public void stop() {
        
    }
}

...

Declaring properties

Code Block
xml
xml
titleXMLxml
<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>
Code Block
java
java
titleAnnotationsjava
@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;
}
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Attribute name

Required

Default value

 

propagation

no

false

specifies if the properties propagation (properties are also published as service properties) is enabled or disabled

managedservice

no

instance name

specifies the PID of the published managed service. // This value can be overidden by the managed.service.pid instance property

name

no

field name or computed from the method name

specifies if the the property name

value

no

 

specifies the default property value

field

no

automatically detected with annotations

specifies the field in which the property value will be injected

method

no

automatically detected with annotations

specifies the setter method in which the property value will be injected

mandatory

no

false

specifies if the property has to receive a value from the instance configuration

Wiki Markup
{div:class=borderedTable} {center} ||Attribute name || Required || Default value || || | propagation | no | false | specifies if the properties propagation (properties are also published as service properties) is enabled or disabled | | managedservice | no | instance name | specifies the PID of the published managed service. // This value can be overidden by the {{managed.service.pid}} instance property | | name | no | field name or computed from the method name | specifies if the the property name | | value | no | | specifies the default property value | | field | no | automatically detected with annotations | specifies the field in which the property value will be injected | | method | no | automatically detected with annotations | specifies the setter method in which the property value will be injected | | mandatory | no | false | specifies if the property has to receive a value from the instance configuration | {center} {div}

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
    titleXMLxml
    <component
         classname="...">
        <provides
    	post-unregistration="unregistered" post-registration="registered"/>
    </component>
    
    Code Block
    java
    java
    titleAnnotationsjava
    @PostRegistration
    public void registered(ServiceReference ref) {
    	System.out.println("Registered");
    }
    
    @PostUnregistration
    public void unregistered(ServiceReference ref) {
    	System.out.println("Unregistered");
    }
    
  • Provided Service Handler

...

  • 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
    titleXMLxml
    <component
         classname="...">
        <provides>
            <controller field="controller" value="false"/>
        </provides>
    </component>
    
    Code Block
    java
    java
    titleAnnotationsjava
    @ServiceController(value="false")
    private boolean controller
    
  • Provided Service Handler

...

  • Deploy the 'arch' command bundle (available for Felix and Equinox)
  • Launch the 'arch' command in the OSGi Framework Shell
    Code Block
    java
    java
    titleFelix Shelljava
    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
    titleFelix Gogojava
    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
    

...

  • 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.
Code Block
xml
xml
titleXMLxml
<iPOJO xmlns:temporal="org.apache.felix.ipojo.handler.temporal">
<component
    className="my.Implementation">

    <!-- Temporal dependency configuration -->
    <temporal:requires field="mytemporal"/>
    <provides/>
</component>
</iPOJO>
Code Block
java
java
titleAnnotationsjava
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;
    
}
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Attribute name

Required

Default value

 

field

no

automatically detected with annotations

specifies the field in which the service object will be injected

timeout

no

3000 ms

specifies the timeout value (in ms). When the timeout is reached, the on timeout policy is executed

onTimeout

no

Runtime Exception

specifies the on timeout policy. Possible values are: null, nullable, empty, default-implementation (class name)

specification

only when using Collections

 

specifies the required service specification. This attribute is required when the injected field is a Collection

proxy

no

false

enables/disables proxy injection. Service injected as proxies can be given to collaborators

filter

no

no filter

Filter use to discover matching filter.

Wiki Markup
{div:class=borderedTable} {center} ||Attribute name || Required || Default value || || | field | no | automatically detected with annotations | specifies the field in which the service object will be injected | | timeout | no | 3000 ms | specifies the timeout value (in ms). When the timeout is reached, the on timeout policy is executed | | onTimeout | no | Runtime Exception | specifies the on timeout policy. Possible values are: {{null}}, {{nullable}}, {{empty}}, _default-implementation_ (class name) | | specification | only when using Collections | | specifies the required service specification. This attribute is required when the injected field is a Collection | | proxy | no | false | enables/disables proxy injection. Service injected as proxies can be given to collaborators | | filter | no | no filter | Filter use to discover matching filter. | {center} {div}

...

  • 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.
Code Block
xml
xml
titleXMLxml
<ipojo
    xmlns:ev="org.apache.felix.ipojo.handlers.event.EventAdminHandler">
	<component className="...MyComponent">
		<ev:subscriber
			name="mySubscriber"
			callback="receive"
			topics="foo"/>
	</component>
</ipojo>
Code Block
java
java
titleAnnotationsjava
@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
    }
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Wiki Markup
{div:class=borderedTable} {center} ||Attribute name || Required || Default value || || | name | yes | | specifies the name of the event subscriber, acting as a unique identifier. This name is used to configure event subscription in the instance configuration. | | callback (or method) | yes \\ automatically detected with annotations | | specifies The name of the method called each time an event is received. This method takes only one parameter, of type {{
Center

Attribute name

Required

Default value

 

name

yes

 

specifies the name of the event subscriber, acting as a unique identifier. This name is used to configure event subscription in the instance configuration.

callback (or method)

yes
automatically detected with annotations

 

specifies The name of the method called each time an event is received. This method takes only one parameter, of type

org.osgi.service.event.Event

}}

by

default,

but

this

type

can

be

overridden

by

defining

the

{{

data-key

}}

and/or

the

{{

data-type

}}

attributes.

| | topics | yes | | specifies the list

topics

yes

 

specifies the list (comma-separated-list)

of

the

topics

that

the

handler

will

listen

to.

Each

event

sent

on

a

topic

present

in

this

list

will

be

sent

to

the

specified

callback

method.

This

parameter

can

be

overridden

by

instances

| |

data-key

\\


data_key

when

using

annotations

| no | | specifies the data key used when you want to receive data events. This attribute's value is the key corresponding to the received data in the event's dictionary. If you use this attribute, the parameter passed to the callback method is the the value associated to this key, not the whole event. This attribute is generally used with the {{data-type}} attribute to specify the received object type. If an event is received and it does not contain such a key, it is ignored (with a warning message). | | data-type \\ data_type when using annotations | no | java.lang.Object | specifies the type of objects ({{java.lang.Object}} by default) that the callback expects. It is used to determine the unique callback method (in case of multiple methods with the same name) and to check type compliance at event reception. Data events that are not corresponding to the specified type will be ignored (with a warning message).| | filter | no | no filter | specifies the event LDAP filter used to filter incoming events before sending them to the callback. The syntax of this field is described in the OSGi EventAdmin Specification. If you don't specify a filter, all events sent on the listened topics will be considered. | {center} {div}

no

 

specifies the data key used when you want to receive data events. This attribute's value is the key corresponding to the received data in the event's dictionary.
If you use this attribute, the parameter passed to the callback method is the the value associated to this key, not the whole event. This attribute is generally used with the data-type attribute to specify the received object type. If an event is received and it does not contain such a key, it is ignored (with a warning message).

data-type
data_type when using annotations

no

java.lang.Object

specifies the type of objects (java.lang.Object by default) that the callback expects. It is used to determine the unique callback method (in case of multiple methods with the same name) and to check type compliance at event reception. Data events that are not corresponding to the specified type will be ignored (with a warning message).

filter

no

no filter

specifies the event LDAP filter used to filter incoming events before sending them to the callback. The syntax of this field is described in the OSGi EventAdmin Specification. If you don't specify a filter, all events sent on the listened topics will be considered.

  • Instance configuration
    • event.topics : overrides topics attribute
    • event.filter : overrides filter attribute
Code Block
xml
xml
titleInstance configurationxml
<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>

...

  • 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.
Code Block
xml
xml
titleXMLxml
<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>
Code Block
java
java
titleAnnotationsjava

@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);
    }
}
Div
classborderedTable
Wiki Markup
{div:class=borderedTable} {center} ||Attribute name || Required || Default value || || | name | yes | | specifies the name of the event publisher, acting as a unique identifier. This name is used to configure event publishing in the instance configuration. | | field | yes \\ automatically detected with annotations | | specifies The name of the field used to send events. The field is initialized at component instantiation time. The type of the field must be : {{
Center

Attribute name

Required

Default value

 

name

yes

 

specifies the name of the event publisher, acting as a unique identifier. This name is used to configure event publishing in the instance configuration.

field

yes
automatically detected with annotations

 

specifies The name of the field used to send events. The field is initialized at component instantiation time. The type of the field must be :

org.apache.felix.ipojo.handlers.event.publisher.Publisher

}}. | | topics | yes | | specifies the list

.

topics

yes

 

specifies the list (comma-separated-list)

of

the

topics

on

which

events

will

be

sent.

This

parameter

can

be

overridden

by

instances

| |

data-key

\\


data_key

when

using

annotations

| no |

no

user.data

|

specifies

the

data

key

used

when

you

want

to

send

data

events.

This

attribute's

value

is

the

key,

in

the

event's

dictionary,

in

which

sent

data

are

stored.

When

you

use

the

_

sendData

_

method

of

the

Publisher,

the

given

object

is

placed

in

the

event

dictionary,

associated

with

the

specified

data-key.

| | synchronous | no | false | specifies if event sending is synchronous or not. | {center} {div}

synchronous

no

false

specifies if event sending is synchronous or not.

  • Instance configuration
    • event.topics : overrides topics attribute
Code Block
xml
xml
titleInstance configurationxml
<instance component="...MyComponent">
		<property name="event.topics">
			<property name="myPublisher" value="foo"/>
		</property>
	</instance>

...

  • 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.
Code Block
xml
xml
titleXMLxml
<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>

Code Block
java
java
titleAnnotationsjava
@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
    }
}
Div
classborderedTable
Center

Attribute name

Required

Default value

 

extension

yes

 

specifies the required extension

Wiki Markup
{div:class=borderedTable} {center} ||Attribute name || Required || Default value || || | extension | yes | | specifies the required extension

(i.e.

the

required

Manifest

key)

| | onArrival | yes | | specifies the method called when a matching bundle arrives. The method receives the Bundle object and the extension value | | onDeparture | yes | | specifies the method called when a matching bundle leaves. The method receives the Bundle object | {center} {div}

onArrival

yes

 

specifies the method called when a matching bundle arrives. The method receives the Bundle object and the extension value

onDeparture

yes

 

specifies the method called when a matching bundle leaves. The method receives the Bundle object

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.
Code Block
xml
xml
titleXMLxml
<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>
Code Block
java
java
titleAnnotationsjava
@Component
@org.apache.felix.ipojo.whiteboard.Wbp(filter="(my.property=1)", 
        onArrival="onArrival", 
        onDeparture="onDeparture",
        onModification="onModification")
public class WhiteBoardWIModification {
    
    public void onArrival(ServiceReference ref) {
        // ...
    }
 
    public void onDeparture(ServiceReference ref) {
        // ...
    }
    
    public void onModification(ServiceReference ref) {
        // ...
    }

}
Center

Attribute name

Required

Default value

 

filter

yes

 

specifies LDAP filter used to detect required service providers

onArrival

yes

 

specifies the method called when a matching service provider arrives. The method receives the ServiceReference object

onDeparture

yes

 

specifies the method called when a matching service provider leaves. The method receives the ServiceReference object

omModification

no

 

specifies the method called when a matching service provider is modified and is still matching. The method receives the ServiceReference object

Wiki Markup
{center} ||Attribute name || Required || Default value || || | filter | yes | | specifies LDAP filter used to detect required service providers | | onArrival | yes | | specifies the method called when a matching service provider arrives. The method receives the ServiceReference object | | onDeparture | yes | | specifies the method called when a matching service provider leaves. The method receives the ServiceReference object | | omModification | no | | specifies the method called when a matching service provider is modified and is still matching. The method receives the ServiceReference object | {center}