Table of Contents

1. About the Fraclet Annotation Framework
2. Fraclet XDoc: An XDoclet2 plugin for Fractal

About the Fraclet Annotation Framework

Fraclet is an annotation framework for the Fractal component model. Fraclet is composed of several annotations and plugins to generate automatically various artifacts required by the Fractal component model. Annotations provide a way to describe the component meta-information directly in the source code of the content class. Fraclet plugins generate either Fractal component glue, FractalADL definitions or Monolog configurations.

This approach has several benefits:

• You don't have to worry about out dating deployment meta-data whenever you touch the code. The deployment meta-data is continuously integrated.
• Working with only one file per component gives you a better overview of what you're doing. If your component consists of several files, it's easy to lose track. If you have ever written an Enterprise Java Bean, you know what we mean. A single EJB can typically consists of 7 or more files. With Fraclet you only maintain one of them, and the rest is generated.
• You dramatically reduce development time, and can concentrate on business logic, while Fraclet generates 60% of the code for you.

Fraclet XDoc: An XDoclet2 plugin for Fractal

Fraclet uses the XDoclet2 as annotation parser and generation engine.

XDoclet is an open source code generation engine. It enables Attribute-Oriented Programming for java. In short, this means that you can add more significance to your code by adding meta data (attributes) to your java sources. This is done in special JavaDoc tags. This use of JavaDoc tags for attributes formed the original ideas for Java 5 Annotations.

XDoclet2 is the next generation of this technology. Based on Generama, it uses standard template engines such as Velocity and Freemarker for generation of text-oriented output, and Jelly for XML output. The function of XDoclet2 is to seed the generation contexts for these template engines.

XDoclet2 is supported by XDoclet2 plugins, which provide task-specific generation functionality.

This part describes the features of this XDoclet2 plugin for Fractal, and the way to use them.

1. Available Annotations
2. Available Plugins

Available Annotations

Some annotations have been defined in order to describe the component meta-information. The list below describes these annotations.

@fractal.itf

Details:

This class annotation adds the name information to the definition of a Fractal interface. This name is required by the Fractal component model to identify the interfaces required and provided by a Fractal component. This annotation can also override the associated interface signature to introduce interface meta-information at the class level.

Parameters:

Examples:

/** @fractal.itf name="m" */
public interface Main { ... }

/** @fractal.itf name="r" signature="java.lang.Runnable" */
public class Client implements Runnable { ... }
                

@fractal.ctrl

Details:

This class annotation allows the developer to describe the description of the controller part that should be associated to the content part of the Fractal component.

Parameters:

Example:

/** @fractal.ctrl desc="primitive" */
public class Client implements Runnable { ... }
                

@fractal.tmpl

Details:

This class annotation allows the developer to describe the description of the controller part that should be associated to the template part of the Fractal component.

Parameters:

Example:

/** @fractal.tmpl desc="primitiveTemplate" */
public class Client implements Runnable { ... }
                

@monolog.handler

Details:

This class annotation allows the developer to describe a Monolog handler specific to the Fractal component. The available annotation attributes support the various properties that can be defined in a Monolog configuration file.

Parameters:

Example:

/** @monolog.handler name="clientHandler" output="System.err" pattern="%-5l [%h] <%t> %m%n" */
public class Client implements Runnable { ... }
                

@fractal.ac

Details:

This field annotation describes a Fractal attribute. A Fractal attribute is a Java attribute whose value can be configured and introspected from the Fractal component. Fractal attributes are managed by the attribute control feature of the Fractal component model.

Parameters:

Example:

public class Client implements Runnable {
  /** @fractal.ac name="count" value=2 */
  protected int counter; // field should be declared as protected or public.

  /** @fractal.ac argument="client-prefix" */
  protected String pref;

  /** @fractal.ac */
  protected String suffix;

  ...
}
                

@fractal.bc

Details:

This field annotation describes a Fractal binding. A Fractal binding is a Java attribute representing a client interface. Fractal bindings are managed by the binding control feature of the Fractal component model.

Parameters:

Example:

public class Client implements Runnable {
  /** @fractal.bc name="s" signature="Service" cardinality="collection" */
  protected Map servers = new HashMap(); // collections are stored in a map

  /** @fractal.bc */
  protected Service service;

  ...
}
                

@fractal.rc

Details:

This field annotation provides a way to refer a control interface provided by the controller part of the associated Fractal component.

Parameters:

Example:

public class Client implements Runnable {
  /** @fractal.rc controller="name-controller" */
  protected NameController nc; // field should be declared as protected or public.

  /** @fractal.rc  */
  protected Component self;

  ...
}
                

@fractal.log

Details:

This field annotation provides a way to define a Monolog logger to log the execution of the Fractal component.

Parameters:

Example:

public class Client implements Runnable {
  /** @fractal.log name="c" handler="clientHandler,consoleHandler" */
  protected Logger log; // field should be declared as protected or public.

  /** @fractal.log */
  protected Logger log2;

  ...
}
                

Julia Configuration:

To enable the Monolog support in Julia, the julia.cfg configuration file should be modified to override the lifecycle-controller-impl definition as follows:

...                  
                  
# LifeCycleController implementation (for primitive or composite components)
(lifecycle-controller-impl
  ((org.objectweb.fractal.julia.asm.MixinClassGenerator
        LifeCycleControllerImpl
        org.objectweb.fractal.julia.BasicControllerMixin
        org.objectweb.fractal.julia.UseComponentMixin
        org.objectweb.fractal.julia.control.lifecycle.BasicLifeCycleCoordinatorMixin
        org.objectweb.fractal.julia.control.lifecycle.BasicLifeCycleControllerMixin
        # to check that mandatory client interfaces are bound in startFc:
        org.objectweb.fractal.julia.control.lifecycle.TypeLifeCycleMixin
        # to automatically assign the logger and logger factory:
        org.objectweb.fractal.julia.BasicInitializableMixin
        org.objectweb.fractal.julia.logger.LoggerLifeCycleMixin        
        # to notify the encapsulated component (if present) when its state changes:
        org.objectweb.fractal.julia.control.lifecycle.ContainerLifeCycleMixin
  ) 
        # optional initialization parameter (monolog configuration file name):
        (monolog-conf-file monolog.properties)
  )
)
 
...                                   
                  

AOKell Configuration:

To enable the Monolog support in AOKell, the build.properties configuration file should be modified to activate the feature.loggable.on property as follows:

...
                  
# The loggable feature determines whether primitive components are equipped
# with a monolog logger or not (which is the default case).
# Uncomment the following property for using primitive components equipped
# with a monolog logger.
feature.loggable.on 	true                  

...
                

Available Plugins

Some plugins have been defined in order to generate the component artifacts. The list below describes these plugins:

AttributeControllerPlugin

Details:

Generates the <CLASS>AttributeController interface associated to a <CLASS> class if it defines at least an attribute using the @fractal.ac annotation.

Usage:

<target name="compile">
  <taskdef name="xdoclet" classname="org.xdoclet.ant.XDocletTask" classpathref="classpath"/>
  <mkdir dir="${gen}"/>
  <xdoclet>
    <fileset dir="${src}" includes="**/*.java" />
    <component destdir="${gen}" classname="org.objectweb.fractal.fraclet.AttributeControllerPlugin"/>
  </xdoclet>
  ...
</target>
                

PrimitiveComponentPlugin

Details:

Generates the Fc<CLASS> class associated to a <CLASS> class. class if it defines either a @fractal.ac, @fractal.bc, @fractal.rc or/and @fractal.log annotation.

Usage:

<target name="compile">
  <taskdef name="xdoclet" classname="org.xdoclet.ant.XDocletTask" classpathref="classpath"/>
  <mkdir dir="${gen}"/>
  <xdoclet>
    <fileset dir="${src}" includes="**/*.java" />
    <component destdir="${gen}" classname="org.objectweb.fractal.fraclet.PrimitiveComponentPlugin"/>
  </xdoclet>
  ...
</target>
                

PrimitiveDefinitionPlugin

Generates the <CLASS>.fractal definition associated to a <CLASS> class (or interface).

Usage:

<target name="compile">
  <taskdef name="xdoclet" classname="org.xdoclet.ant.XDocletTask" classpathref="classpath"/>
  <mkdir dir="${build}"/>
  <xdoclet>
    <fileset dir="${src}" includes="**/*.java" />
    <component destdir="${build}" classname="org.objectweb.fractal.fraclet.PrimitiveDefinitionPlugin"/>
  </xdoclet>
  ...
</target>
                

CompositeDefinitionPlugin

Details:

Generates the <CLASS>Comp.fractal definition associated to a <CLASS> class if it defines at least a @fractal.bc annotation.

Usage:

<target name="compile">
  <taskdef name="xdoclet" classname="org.xdoclet.ant.XDocletTask" classpathref="classpath"/>
  <mkdir dir="${build}"/>
  <xdoclet>
    <fileset dir="${src}" includes="**/*.java" />
    <component destdir="${build}" classname="org.objectweb.fractal.fraclet.CompositeDefinitionPlugin"/>
  </xdoclet>
  ...
</target>
                

MonologConfigurationPlugin

Details:

Generates the monolog.properties configuration file for the Monolog tool.

Usage:

<target name="compile">
  <taskdef name="xdoclet" classname="org.xdoclet.ant.XDocletTask" classpathref="classpath"/>
  <mkdir dir="${build}"/>
  <xdoclet>
    <fileset dir="${src}" includes="**/*.java" />
    <component destdir="${build}" classname="org.objectweb.fractal.fraclet.MonologConfigurationPlugin"/>
  </xdoclet>
  ...
</target>