Package com.sapportals.wcm.util.factories

Provides base classes for factory implementations.

See:
Description

Class Summary

AbstractObjectFactory	A factory which produces configurable objects.
ReflectionUtils	A wrapper for reflection methods with an WcmException .
ThreadUtils	Some tools for starting threads.

Package com.sapportals.wcm.util.factories Description

Provides base classes for factory implementations.

Package Specification

Factories are a standard design pattern.
A simple factory, which will create SampleWcmObjects, would look like that:

public class SampleWcmObjectFactory
extends AbstractClassFactory {

  private static final String ID = "samplewcmobject";

  public SampleWcmObjectFactory(String id) {
    super("SampleWcmObjectFactory", id);
  }

  protected void onInitialize()
                       throws WcmException {
    readConfig();
    loadClass();
  }

  protected static SchedulerFactory getInstance()
                                         throws WcmException {
    return (SampleWcmObjectFactory)getFactoryInstance(SampleWcmObjectFactory.class, SINGLETON, ID);
  }

  public static ISampleWcmObject getSampleWcmObject()
                                             throws WcmException {
    return (ISampleWcmObject)getInstance().getClassInstance();
  }

}

To get an object from the factory, one would call the getSampleWcmObject() method, wich will call getInstance() at first:
getInstance() calls the AbstractClassFactory's method getFactoryInstance(). This method expects the class-object of the factory, the type of instanciation (SINGLETON or MULTI) and the id for the factory as parameters. It will call the given classes constructor, passing the id as the constructors parameter. The constructor initializes the base class by calling the AbstractClassFactory's constructor via super().
After creating a new instance of the factory, getFactoryInstance() calls the factories method onInitialize(). The onInitialize() method should do two things:

1. readConfig() loads the configuration data (the WCM config properties, prefixed by the id of the factory).
2. loadClass() loads the class with the name defined in the id.class config property (samplewcmobject.class in the sample code).

Afterwards the class for the objects to be produced by the factory is loaded.
So the new factory instance is returned by getInstance() to getSampleWcmObject() and the AbstractClassFactory's method getClassInstance() is called. This method calls the constructor of the class loaded by loadClass(), passing the config properties as the parameter to this constructor.
Finally the newly created instance is returned as the new object.

Therefore, a constructor for SampleWcmObjects should look like this:

public class SampleWcmObject implements ISampleWcmObject {

  public SampleWcmObject(Properities property) {
  }

}

Such an object will be dynamically created by a call to SampleWcmObjectFactory.getSampleWcmObject(), if the SampleWcmObjectFactory is properly configured (with the config entry:

samplewcmobject.class = SampleWcmObject

).