com.livis.livingtalks.ejb
Class EntityHandler

java.lang.Object
  |
  +--com.livis.livingtalks.ejb.EntityHandler

Direct Known Subclasses:

CachingEntityHandler

public class EntityHandler

extends java.lang.Object

EntityHandler is a generic class capable of acting as a fassade to any of our entity beans. In an ideal world, our entity beans would have been derived from a common base class. General algorithms acting on them would then have used the base class interface. We have at least one such algorithm in our system: the cache. Therefore, we need a solution. EJBs are components, not objects, and cannot be derived from each other.

The first idea is that their implementations can, but wait: Imagine we would have definded a base method setModel (AbstractModel m) in our entity bean base class. Then, because of RMI-IIOP we would have got a Corba-Exception when calling setModel with, e.g., an AuthorModel m as argument. The solution presented here encapsulates all breaches of object-oriented design in this single file.

This is also a nice example where the difference between RMI-IIOP and RMI affects the entire system design.

Field Summary

protected java.lang.reflect.Method	creatorModel
protected java.lang.reflect.Method	finder1
protected java.lang.reflect.Method	finder1a
protected java.lang.reflect.Method	finder2
protected java.lang.reflect.Method	finderAll
protected java.lang.reflect.Method	finderByPrimaryKey
protected java.lang.reflect.Method	getterModel
protected java.lang.reflect.Method	setterModel

Constructor Summary

protected

EntityHandler(java.lang.String homeName, java.lang.Class homeClass)

Method Summary

java.lang.String	create(AbstractModel model)
java.util.Collection	getKeys1(java.lang.Object a)
java.util.Collection	getKeys1a(java.lang.Object a)
java.util.Collection	getKeys2(java.lang.Object a, java.lang.Object b)
java.util.Collection	getKeysAll()
AbstractModel	getModel(java.lang.String key)
AbstractModel	getShortmodel(java.lang.String key)
java.util.Collection	getShortmodelsAll()
void	remove(java.lang.String key)
void	setModel(AbstractModel model)

Methods inherited from class java.lang.Object

, clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

getterModel

protected java.lang.reflect.Method getterModel

setterModel

protected java.lang.reflect.Method setterModel

creatorModel

protected java.lang.reflect.Method creatorModel

finderByPrimaryKey

protected java.lang.reflect.Method finderByPrimaryKey

finderAll

protected java.lang.reflect.Method finderAll

finder1

protected java.lang.reflect.Method finder1

finder1a

protected java.lang.reflect.Method finder1a

finder2

protected java.lang.reflect.Method finder2

Constructor Detail

EntityHandler

protected EntityHandler(java.lang.String homeName,
                        java.lang.Class homeClass)

Method Detail

getModel

public AbstractModel getModel(java.lang.String key)

getShortmodel

public AbstractModel getShortmodel(java.lang.String key)

setModel

public void setModel(AbstractModel model)
              throws javax.ejb.CreateException

remove

public void remove(java.lang.String key)
            throws com.livis.livingtalks.ejb.RemoveException

create

public java.lang.String create(AbstractModel model)
                        throws javax.ejb.CreateException

getShortmodelsAll

public java.util.Collection getShortmodelsAll()

getKeysAll

public java.util.Collection getKeysAll()

getKeys1

public java.util.Collection getKeys1(java.lang.Object a)

getKeys1a

public java.util.Collection getKeys1a(java.lang.Object a)

getKeys2

public java.util.Collection getKeys2(java.lang.Object a,
                                     java.lang.Object b)