package org.qi4j.runtime.association;
import org.qi4j.api.entity.EntityComposite;
import org.qi4j.api.entity.EntityReference;
import org.qi4j.api.association.AbstractAssociation;
import org.qi4j.functional.Function2;
import org.qi4j.runtime.composite.ProxyReferenceInvocationHandler;
import org.qi4j.runtime.entity.EntityInstance;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Proxy;
import java.lang.reflect.Type;
/**
* Implementation of AbstractAssociation. Includes helper methods for subclasses
*/
public abstract class AbstractAssociationInstance<T>
implements AbstractAssociation
{
protected AssociationInfo associationInfo;
private Function2<EntityReference, Type, Object> entityFunction;
public AbstractAssociationInstance( AssociationInfo associationInfo,
Function2<EntityReference, Type, Object> entityFunction
)
{
this.associationInfo = associationInfo;
this.entityFunction = entityFunction;
}
public AssociationInfo getAssociationInfo()
{
return associationInfo;
}
public void setAssociationInfo(AssociationInfo newInfo)
{
this.associationInfo = newInfo;
}
protected T getEntity( EntityReference entityId )
{
if( entityId == null )
{
return null;
}
return (T) entityFunction.map( entityId, associationInfo.type() );
}
protected EntityReference getEntityReference( Object composite )
{
if( composite == null )
{
return null;
}
InvocationHandler handler = Proxy.getInvocationHandler( composite );
if( handler instanceof ProxyReferenceInvocationHandler )
{
handler = Proxy.getInvocationHandler( ( (ProxyReferenceInvocationHandler) handler ).proxy() );
}
EntityInstance instance = (EntityInstance) handler;
return instance.identity();
}
protected void checkType( Object instance )
{
if( instance != null )
{
if( !( instance instanceof EntityComposite ) )
{
if( instance instanceof Proxy )
{
if( Proxy.getInvocationHandler( instance ) instanceof EntityInstance )
{
return; // It's fine
}
}
throw new IllegalArgumentException( "Object must be an EntityComposite" );
}
}
}
protected void checkImmutable() throws IllegalStateException
{
if( associationInfo.isImmutable() )
{
throw new IllegalStateException( "Association [" + associationInfo.qualifiedName() + "] is immutable." );
}
}
}