DPML Notify

[mcconnell AT dpml.net]

Author: mcconnell AT dpml.net
Date: Tue Apr  5 09:31:19 2005
New Revision: 2209

Added:
   
development/main/metro/automation/control/src/main/net/dpml/automation/model/PartClassNotFoundException.java
   
development/main/metro/automation/control/src/main/net/dpml/automation/model/ServiceClassNotFoundException.java
   
development/main/metro/automation/control/src/main/net/dpml/automation/model/TypeClassNotFoundException.java
   
development/main/metro/composition/control/src/main/net/dpml/composition/models/DuplicateKeyException.java
   
development/main/metro/composition/control/src/main/net/dpml/composition/models/InvalidModelException.java
   
development/main/metro/composition/control/src/main/net/dpml/composition/models/MissingDependencyDirectiveException.java
   
development/main/metro/composition/control/src/main/net/dpml/composition/models/MissingPartException.java
   
development/main/metro/composition/control/src/main/net/dpml/composition/models/PartsModel.java
   
development/main/metro/composition/control/src/main/net/dpml/composition/models/UnresolvableDependencyException.java
Modified:
   
development/main/metro/automation/control/src/main/net/dpml/automation/model/ModelRuntimeException.java
   
development/main/metro/composition/control/src/main/net/dpml/composition/control/Holder.java
   
development/main/metro/composition/control/src/main/net/dpml/composition/control/LifecycleHandler.java
   
development/main/metro/composition/control/src/main/net/dpml/composition/models/StandardComponentModel.java
   
development/main/metro/composition/testing/acme/src/main/net/dpml/composition/testing/AcmeContainer.java
   
development/main/metro/composition/testing/acme/src/main/net/dpml/composition/testing/DefaultGizmo.java
   
development/main/metro/composition/testing/acme/src/main/net/dpml/composition/testing/DefaultWidget.java
Log:
Separate parts into a nested model (keeping the primary model simpler and 
easier to follow).

Modified: 
development/main/metro/automation/control/src/main/net/dpml/automation/model/ModelRuntimeException.java
==============================================================================
--- 
development/main/metro/automation/control/src/main/net/dpml/automation/model/ModelRuntimeException.java
     (original)
+++ 
development/main/metro/automation/control/src/main/net/dpml/automation/model/ModelRuntimeException.java
     Tue Apr  5 09:31:19 2005
@@ -26,10 +26,14 @@
  */
 public class ModelRuntimeException extends RuntimeException 
 {
+    public ModelRuntimeException( String message )
+    {
+        super( message );
+    }
+
     public ModelRuntimeException( String message, Throwable cause )
     {
         super( message, cause );
     }
-
 }
 

Added: 
development/main/metro/automation/control/src/main/net/dpml/automation/model/PartClassNotFoundException.java
==============================================================================
--- (empty file)
+++ 
development/main/metro/automation/control/src/main/net/dpml/automation/model/PartClassNotFoundException.java
        Tue Apr  5 09:31:19 2005
@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2005 Stephen J. McConnell
+ *
+ * Licensed  under the  Apache License,  Version 2.0  (the "License");
+ * you may not use  this file  except in  compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed  under the  License is distributed on an "AS IS" BASIS,
+ * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY KIND, either  express  or
+ * implied.
+ *
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.dpml.automation.model;
+
+/**
+ * Exception thrown when an attempt is made to locate a class declared 
+ * by a parts accessor and the class cannot be found.
+ *
+ * @author <a href="mailto:dev-dpml AT lists.ibiblio.org";>The Digital Product 
Meta Library</a>
+ * @version $Revision: 1.2 $ $Date: 2004/03/17 10:30:09 $
+ */
+public class PartClassNotFoundException extends ModelRuntimeException 
+{
+    private String m_classname;
+
+    public PartClassNotFoundException( String classname )
+    {
+        super( classname );
+        m_classname = classname;
+    }
+
+    public String getClassname()
+    {
+        return m_classname;
+    }
+}
+

Added: 
development/main/metro/automation/control/src/main/net/dpml/automation/model/ServiceClassNotFoundException.java
==============================================================================
--- (empty file)
+++ 
development/main/metro/automation/control/src/main/net/dpml/automation/model/ServiceClassNotFoundException.java
     Tue Apr  5 09:31:19 2005
@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2005 Stephen J. McConnell
+ *
+ * Licensed  under the  Apache License,  Version 2.0  (the "License");
+ * you may not use  this file  except in  compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed  under the  License is distributed on an "AS IS" BASIS,
+ * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY KIND, either  express  or
+ * implied.
+ *
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.dpml.automation.model;
+
+/**
+ * Unexpected runtime exception indicating an internal model error.
+ *
+ * @author <a href="mailto:dev-dpml AT lists.ibiblio.org";>The Digital Product 
Meta Library</a>
+ * @version $Revision: 1.2 $ $Date: 2004/03/17 10:30:09 $
+ */
+public class ServiceClassNotFoundException extends ModelRuntimeException 
+{
+    private String m_serviceClassname;
+    private String m_componentClassname;
+
+    public ServiceClassNotFoundException( String componentClassname, String 
serviceClassname )
+    {
+        super( buildMessage( componentClassname, serviceClassname ) );
+        m_serviceClassname = serviceClassname;
+        m_componentClassname = componentClassname;
+    }
+
+    public String getComponentClassname()
+    {
+        return m_componentClassname;
+    }
+
+    public String getServiceClassname()
+    {
+        return m_serviceClassname;
+    }
+
+    private static String buildMessage( String componentClassname, String 
serviceClassname )
+    {
+        String error = 
+          "Service class ["
+          + serviceClassname 
+          + "] declared by the component type ["
+          + componentClassname
+          + "] was not found.";
+        return error;
+    }
+
+}
+

Added: 
development/main/metro/automation/control/src/main/net/dpml/automation/model/TypeClassNotFoundException.java
==============================================================================
--- (empty file)
+++ 
development/main/metro/automation/control/src/main/net/dpml/automation/model/TypeClassNotFoundException.java
        Tue Apr  5 09:31:19 2005
@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2005 Stephen J. McConnell
+ *
+ * Licensed  under the  Apache License,  Version 2.0  (the "License");
+ * you may not use  this file  except in  compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed  under the  License is distributed on an "AS IS" BASIS,
+ * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY KIND, either  express  or
+ * implied.
+ *
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.dpml.automation.model;
+
+/**
+ * Unexpected runtime exception indicating an internal model error.
+ *
+ * @author <a href="mailto:dev-dpml AT lists.ibiblio.org";>The Digital Product 
Meta Library</a>
+ * @version $Revision: 1.2 $ $Date: 2004/03/17 10:30:09 $
+ */
+public class TypeClassNotFoundException extends ModelRuntimeException 
+{
+    private String m_classname;
+
+    public TypeClassNotFoundException( String classname )
+    {
+        super( classname );
+        m_classname = classname;
+    }
+
+    public String getClassname()
+    {
+        return m_classname;
+    }
+}
+

Modified: 
development/main/metro/composition/control/src/main/net/dpml/composition/control/Holder.java
==============================================================================
--- 
development/main/metro/composition/control/src/main/net/dpml/composition/control/Holder.java
        (original)
+++ 
development/main/metro/composition/control/src/main/net/dpml/composition/control/Holder.java
        Tue Apr  5 09:31:19 2005
@@ -69,6 +69,16 @@
         return m_key;
     }
 
+    public StandardComponentModel getModel()
+    {
+        return m_model;
+    }
+
+    public Object getQualifiedName()
+    {
+        return getModel().getQualifiedName() + "#" + getKey().toString();
+    }
+
     public Object newProxy() throws Exception
     {
         synchronized( m_proxies )
@@ -93,7 +103,7 @@
             }
             if( null == m_instance )
             {
-                m_instance = m_factory.incarnate( m_model );
+                m_instance = m_factory.incarnate( this );
             }
             return m_instance;
         }

Modified: 
development/main/metro/composition/control/src/main/net/dpml/composition/control/LifecycleHandler.java
==============================================================================
--- 
development/main/metro/composition/control/src/main/net/dpml/composition/control/LifecycleHandler.java
      (original)
+++ 
development/main/metro/composition/control/src/main/net/dpml/composition/control/LifecycleHandler.java
      Tue Apr  5 09:31:19 2005
@@ -55,7 +55,27 @@
     }
 
     /**
-     * Execute the incarnation sequence and return a new annonomous 
+     * Execute the incarnation sequence and return a new 
+     * component instance. 
+     *
+     * @return a new component instance
+     */
+    public Object incarnate( Holder holder ) throws LifecycleException
+    {
+        if( getMonitor().isDebugEnabled() )
+        {
+            final String message = 
+              "Incarnating ["
+              + holder.getQualifiedName() 
+              + "].";
+            getMonitor().debug( message );
+        }
+        StandardComponentModel model = holder.getModel();
+        return execute( model );
+    }
+
+    /**
+     * Execute the incarnation sequence and return a new 
      * component instance. 
      *
      * @return a new component instance
@@ -65,12 +85,22 @@
         if( getMonitor().isDebugEnabled() )
         {
             final String message = 
-              "Initiating incarnation using the model ["
+              "Incarnating ["
               + model.getQualifiedName() 
               + "].";
             getMonitor().debug( message );
         }
+        return execute( model );
+    }
 
+    /**
+     * Execute the incarnation sequence and return a new 
+     * component instance. 
+     *
+     * @return a new component instance
+     */
+    private Object execute( StandardComponentModel model ) throws 
LifecycleException
+    {
         Class subject = model.getDeploymentClass();
         ClassLoader classloader = subject.getClassLoader();
         Constructor constructor = getConstructor( subject );

Added: 
development/main/metro/composition/control/src/main/net/dpml/composition/models/DuplicateKeyException.java
==============================================================================
--- (empty file)
+++ 
development/main/metro/composition/control/src/main/net/dpml/composition/models/DuplicateKeyException.java
  Tue Apr  5 09:31:19 2005
@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2005 Stephen J. McConnell
+ *
+ * Licensed  under the  Apache License,  Version 2.0  (the "License");
+ * you may not use  this file  except in  compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed  under the  License is distributed on an "AS IS" BASIS,
+ * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY KIND, either  express  or
+ * implied.
+ *
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.dpml.composition.models;
+
+import net.dpml.automation.model.ModelException;
+
+import net.dpml.composition.data.DependencyDirective;
+
+/**
+ * Exception thrown in response to an attempt to register a part model 
+ * under a key that is already assigned.
+ *
+ * @author <a href="mailto:dev-dpml AT lists.ibiblio.org";>The Digital Product 
Meta Library</a>
+ * @version $Revision: 1.2 $ $Date: 2004/03/17 10:30:09 $
+ */
+public class  DuplicateKeyException extends ModelException 
+{
+    private String m_key;
+
+    public DuplicateKeyException( String key )
+    {
+        super( key );
+        m_key = key;
+    }
+
+    public String getKey()
+    {
+        return m_key;
+    }
+}
+

Added: 
development/main/metro/composition/control/src/main/net/dpml/composition/models/InvalidModelException.java
==============================================================================
--- (empty file)
+++ 
development/main/metro/composition/control/src/main/net/dpml/composition/models/InvalidModelException.java
  Tue Apr  5 09:31:19 2005
@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2005 Stephen J. McConnell
+ *
+ * Licensed  under the  Apache License,  Version 2.0  (the "License");
+ * you may not use  this file  except in  compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed  under the  License is distributed on an "AS IS" BASIS,
+ * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY KIND, either  express  or
+ * implied.
+ *
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.dpml.composition.models;
+
+import net.dpml.automation.model.ModelRuntimeException;
+
+/**
+ * Unexpected runtime exception indicating an internal model error.
+ *
+ * @author <a href="mailto:dev-dpml AT lists.ibiblio.org";>The Digital Product 
Meta Library</a>
+ * @version $Revision: 1.2 $ $Date: 2004/03/17 10:30:09 $
+ */
+public class InvalidModelException extends ModelRuntimeException 
+{
+    private Throwable[] m_issues;
+
+    public InvalidModelException( StandardComponentModel model, Throwable[] 
issues )
+    {
+        super( buildMessage( model, issues ) );
+        m_issues = issues;
+    }
+
+    public Throwable[] getIssues()
+    {
+        return m_issues;
+    }
+
+    private static String buildMessage( StandardComponentModel model, 
Throwable[] issues )
+    {
+        final String name = model.getQualifiedName();
+        final String error =  
+          "The component model ["
+          + name
+          + "] contains " 
+          + issues.length
+          + " unresolved ";
+        if( issues.length == 1 )
+        {
+            return error + "issue.";
+        }
+        else
+        {
+            return error + "issues.";
+        }
+    }
+}
+

Added: 
development/main/metro/composition/control/src/main/net/dpml/composition/models/MissingDependencyDirectiveException.java
==============================================================================
--- (empty file)
+++ 
development/main/metro/composition/control/src/main/net/dpml/composition/models/MissingDependencyDirectiveException.java
    Tue Apr  5 09:31:19 2005
@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2005 Stephen J. McConnell
+ *
+ * Licensed  under the  Apache License,  Version 2.0  (the "License");
+ * you may not use  this file  except in  compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed  under the  License is distributed on an "AS IS" BASIS,
+ * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY KIND, either  express  or
+ * implied.
+ *
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.dpml.composition.models;
+
+import net.dpml.automation.model.ModelException;
+
+/**
+ * Unexpected runtime exception indicating an internal model error.
+ *
+ * @author <a href="mailto:dev-dpml AT lists.ibiblio.org";>The Digital Product 
Meta Library</a>
+ * @version $Revision: 1.2 $ $Date: 2004/03/17 10:30:09 $
+ */
+public class MissingDependencyDirectiveException extends ModelException 
+{
+    private StandardComponentModel m_model;
+    private String m_key;
+
+    public MissingDependencyDirectiveException( StandardComponentModel 
model, String key )
+    {
+        super( buildMessage( model, key ) );
+        m_model = model;
+        m_key = key;
+    }
+
+    public String getKey()
+    {
+        return m_key;
+    }
+
+    public StandardComponentModel getModel()
+    {
+        return m_model;
+    }
+
+    private static String buildMessage( StandardComponentModel model, String 
key )
+    {
+        final String name = model.getQualifiedName();
+        final String error =
+          "The component model ["
+          + name
+          + "] does not delcare a dependency directive for the required 
dependency ["
+          + key
+          + "].";
+        return error;
+    }
+}
+

Added: 
development/main/metro/composition/control/src/main/net/dpml/composition/models/MissingPartException.java
==============================================================================
--- (empty file)
+++ 
development/main/metro/composition/control/src/main/net/dpml/composition/models/MissingPartException.java
   Tue Apr  5 09:31:19 2005
@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2005 Stephen J. McConnell
+ *
+ * Licensed  under the  Apache License,  Version 2.0  (the "License");
+ * you may not use  this file  except in  compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed  under the  License is distributed on an "AS IS" BASIS,
+ * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY KIND, either  express  or
+ * implied.
+ *
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.dpml.composition.models;
+
+import net.dpml.automation.model.ModelException;
+
+/**
+ * Unexpected runtime exception indicating an internal model error.
+ *
+ * @author <a href="mailto:dev-dpml AT lists.ibiblio.org";>The Digital Product 
Meta Library</a>
+ * @version $Revision: 1.2 $ $Date: 2004/03/17 10:30:09 $
+ */
+public class MissingPartException extends ModelException 
+{
+    private StandardComponentModel m_model;
+    private String m_key;
+
+    public MissingPartException( StandardComponentModel model, String key )
+    {
+        super( buildMessage( model, key ) );
+        m_model = model;
+        m_key = key;
+    }
+
+    public String getKey()
+    {
+        return m_key;
+    }
+
+    public StandardComponentModel getModel()
+    {
+        return m_model;
+    }
+
+    private static String buildMessage( StandardComponentModel model, String 
key )
+    {
+        final String name = model.getQualifiedName();
+        final String error =
+          "The component model ["
+          + name
+          + "] does not contain a part for the key ["
+          + key
+          + "].";
+        return error;
+    }
+}
+

Added: 
development/main/metro/composition/control/src/main/net/dpml/composition/models/PartsModel.java
==============================================================================
--- (empty file)
+++ 
development/main/metro/composition/control/src/main/net/dpml/composition/models/PartsModel.java
     Tue Apr  5 09:31:19 2005
@@ -0,0 +1,227 @@
+/*
+ * Copyright (c) 2005 Stephen J. McConnell
+ *
+ * Licensed  under the  Apache License,  Version 2.0  (the "License");
+ * you may not use  this file  except in  compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed  under the  License is distributed on an "AS IS" BASIS,
+ * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY KIND, either  express  or
+ * implied.
+ *
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.dpml.composition.models;
+
+import java.io.Serializable;
+import java.util.Map;
+import java.util.Hashtable;
+import java.util.WeakHashMap;
+import java.util.List;
+import java.util.LinkedList;
+
+import net.dpml.automation.model.Model;
+import net.dpml.automation.model.ModelException;
+import net.dpml.automation.model.ModelRuntimeException;
+import net.dpml.automation.model.ServiceClassNotFoundException;
+import net.dpml.automation.model.TypeClassNotFoundException;
+import net.dpml.automation.model.PartClassNotFoundException;
+import net.dpml.automation.control.Controller;
+import net.dpml.automation.control.DelegationException;
+import net.dpml.automation.part.Part;
+
+import net.dpml.composition.data.ComponentProfile;
+import net.dpml.composition.data.ContextDirective;
+import net.dpml.composition.data.DependencyDirective;
+import net.dpml.composition.control.CompositionClassLoader;
+import net.dpml.composition.control.CompositionController;
+import net.dpml.composition.control.Holder;
+
+import net.dpml.meta.info.Type;
+import net.dpml.meta.info.ServiceDescriptor;
+import net.dpml.meta.info.DependencyDescriptor;
+import net.dpml.meta.info.PartDescriptor;
+
+/**
+ * The parts model is a model of the set of parts maintained by a parent 
model.
+ *
+ * @author <a href="mailto:dev-dpml AT lists.ibiblio.org";>The Digital Product 
Meta Library</a>
+ * @version $Revision: 1.2 $ $Date: 2004/03/17 10:30:09 $
+ */
+public class PartsModel implements Serializable
+{
+    private final ClassLoader m_classloader;
+    private final String m_partition;
+    private final CompositionController m_controller;
+    private final StandardComponentModel m_parent;
+
+    private final Map m_parts = new Hashtable();
+    private final List m_errors = new LinkedList();
+
+   /**
+    * Creation of a model representing the parts within a component.
+    * 
+    * @param controller the model controller
+    * @param parent the enclosing parent model
+    * @param partition a name defining the partition within which the parts 
are enclosed
+    * @param classloader the classloader established as the parent for the 
parts
+    * @param profile the component profile from which initial default values 
are established
+    */
+    public PartsModel( 
+       CompositionController controller, StandardComponentModel parent, 
String partition, ClassLoader classloader )
+       throws DelegationException, ModelException
+    {
+        m_controller = controller;
+        m_partition = partition;
+        m_classloader = classloader;
+        m_parent = parent;
+    }
+
+    public Model getModel( String key )
+    {
+        if( null == key )
+        {
+            throw new NullPointerException( "key" );
+        }
+        return (Model) m_parts.get( key ); 
+    }
+
+    public void addModel( String key, Part part ) throws 
DelegationException, ModelException
+    {
+        if( null == key )
+        {
+            throw new NullPointerException( "key" );
+        }
+        if( null == part )
+        {
+            throw new NullPointerException( "part" );
+        }
+        addPartToCollection( key, part, true );
+    }
+
+    public void validate() throws InvalidModelException
+    {
+        if( m_errors.isEmpty() )
+        {
+            return;
+        }
+        else
+        {
+            StandardComponentModel model = getParentModel();
+            Throwable[] issues = getIssues();
+            throw new InvalidModelException( model, issues ); 
+        }
+    }
+
+    private Throwable[] getIssues()
+    {
+        if( m_errors.isEmpty() )
+        {
+            return new Throwable[0];
+        }
+        else
+        {
+            return (Throwable[]) m_errors.toArray( new Throwable[ 0 ] );
+        }
+    }
+
+    void addPartToCollection( String key, Part part, boolean validate ) 
throws DelegationException, ModelException
+    {
+        Model model = loadModelFromPart( part );
+        String k = getKey( key, model );
+        if( m_parts.containsKey( k ) )
+        {
+            throw new DuplicateKeyException( k );
+        }
+        m_parts.put( k, model );
+        if( validate )
+        {
+            build();
+        }
+    }
+
+    private String getKey( String key, Model model )
+    {
+        if( null == key )
+        {
+            return model.getName();
+        }
+        else
+        {
+            return key;
+        }
+    }
+
+    private Model loadModelFromPart( Part part ) throws DelegationException, 
ModelException, DuplicateKeyException
+    {
+        StandardComponentModel parent = getParentModel();
+        String partition = getPartition();
+        ClassLoader classloader = getClassLoader();
+        return getController().getModel( parent, partition, classloader, 
part );
+    }
+
+    private void build()
+    {
+        StandardComponentModel parent = getParentModel();
+        synchronized( m_errors )
+        {
+            m_errors.clear();
+            PartDescriptor[] descriptors = 
m_parent.getType().getPartDescriptors();
+            for( int i=0; i<descriptors.length; i++ )
+            {
+                PartDescriptor descriptor = descriptors[i];
+                String key = descriptor.getKey();
+                Model model = (Model) m_parts.get( key );
+                if( null == model )
+                {
+                    Exception e = new MissingPartException( parent, key );
+                    m_errors.add( e );
+                }
+                else
+                {
+                    //String returnType = descriptor.getType();
+                    //Class returnClass = loadReturnClass( returnType );
+                    //model.getController().....
+                }
+            }
+        }
+    }
+
+    private Class loadReturnClass( ClassLoader classloader, String classname 
)
+    {
+        try
+        {
+            return classloader.loadClass( classname );
+        }
+        catch( ClassNotFoundException cnfe )
+        {
+            throw new PartClassNotFoundException( classname );
+        }
+    }
+
+
+    private StandardComponentModel getParentModel()
+    {
+        return m_parent;
+    }
+
+    private String getPartition()
+    {
+        return m_partition;
+    }
+
+    private ClassLoader getClassLoader()
+    {
+        return m_classloader;
+    }
+
+    private CompositionController getController()
+    {
+        return m_controller;
+    }
+}

Modified: 
development/main/metro/composition/control/src/main/net/dpml/composition/models/StandardComponentModel.java
==============================================================================
--- 
development/main/metro/composition/control/src/main/net/dpml/composition/models/StandardComponentModel.java
 (original)
+++ 
development/main/metro/composition/control/src/main/net/dpml/composition/models/StandardComponentModel.java
 Tue Apr  5 09:31:19 2005
@@ -22,10 +22,14 @@
 import java.util.Map;
 import java.util.Hashtable;
 import java.util.WeakHashMap;
+import java.util.List;
+import java.util.LinkedList;
 
 import net.dpml.automation.model.Model;
 import net.dpml.automation.model.ModelException;
 import net.dpml.automation.model.ModelRuntimeException;
+import net.dpml.automation.model.ServiceClassNotFoundException;
+import net.dpml.automation.model.TypeClassNotFoundException;
 import net.dpml.automation.control.Controller;
 import net.dpml.automation.control.DelegationException;
 import net.dpml.automation.part.Part;
@@ -54,17 +58,27 @@
     private final ClassLoader m_classloader;
     private final String m_partition;
     private final CompositionController m_controller;
+    private final PartsModel m_parts;
 
     private final Class m_class;
     private final Type m_type;
     private final Class[] m_interfaces;
-    private final String m_name;
-    private final String m_lifestyle;
 
     private transient Map m_holders = new WeakHashMap();
-    private final Hashtable m_providers = new Hashtable();
-    private final Hashtable m_parts = new Hashtable();
+    private final Map m_providers = new Hashtable();
+    private final List m_errors = new LinkedList();
 
+    private String m_name;
+    private String m_lifestyle;
+
+   /**
+    * Creation of a new root component model.
+    * 
+    * @param controller the model controller
+    * @param partition a name defineing the partition that this model exists 
within
+    * @param classloader the classloader established for this model
+    * @param profile the component profile from which initial default values 
are established
+    */
     public StandardComponentModel( 
        CompositionController controller, String partition, ClassLoader 
classloader, ComponentProfile profile )
        throws DelegationException, ModelException
@@ -72,6 +86,22 @@
         this( controller, null, partition, classloader, profile );
     }
 
+   /**
+    * Creation of a new nested component model.
+    *
+    * TODO: Update so that the constructor simply established the initial 
state
+    * (including validity) in such a way that we can progromatically update 
the 
+    * state.  As such only a small subset of operations in the constructor 
will
+    * result in a runtime exception (e.g. component class not found, etc.). 
this 
+    * will require the creation of som sub-models such as DependenciesModel, 
+    * ContextModel, PartsModel, etc. - each representing a management 
concern.
+    * 
+    * @param controller the model controller
+    * @param parent the enclosing parent model
+    * @param partition a name defineing the partition that this model exists 
within
+    * @param classloader the classloader established for this model
+    * @param profile the component profile from which initial default values 
are established
+    */
     public StandardComponentModel( 
        CompositionController controller, Model parent, String partition, 
ClassLoader classloader, ComponentProfile profile )
        throws DelegationException, ModelException
@@ -84,12 +114,13 @@
         m_class = loadComponentClass( classloader, profile ); 
         m_type = controller.loadType( m_class );
         m_name = profile.getName();
-        m_lifestyle = profile.getLifestylePolicy();
 
         //
-        // construct an array of the interface classes that the component 
+        // Construct an array of the interface classes that the component 
         // exposes as public services - these will be used when constructing
-        // a proxy to component instances created from this model
+        // a proxy to component instances created from this model.  If an
+        // error occurs while attempting to load a service class - a runtime
+        // exception will be thrown.
         //
 
         ServiceDescriptor[] services = m_type.getServices();
@@ -102,25 +133,35 @@
         m_interfaces = interfaces;
 
         //
+        // set the preferred lifestyle policy
+        //
+
+        m_lifestyle = profile.getLifestylePolicy();
+
+        //
         // Get the set of parts within this part and add them as nested 
models 
         // within this model. There is an issue here concerning selection of 
         // our classloader as the parent for the parts - in effect we need a 
-        // classname that identifies a class in the component's api loader.
+        // classname that identifies a class in the component's api loader 
+        // (or alternatively - we pass the classloader chain into the 
constructor)
         //
 
         String newPartition = getQualifiedName() + "/";
+        m_parts = new PartsModel( controller, this, newPartition, 
classloader );
         Part[] parts = profile.getParts();
         for( int i=0; i<parts.length; i++ )
         {
             Part part = parts[i];
-            Model model = getController().getModel( this, newPartition, 
m_classloader, part );
-            m_parts.put( model.getName(), model );
+            m_parts.addPartToCollection( null, part, false );
         }
 
         //
-        // Any dependencies declared by the component part must be resolvable
-        // by the enclosing model's controller (if available). We use the 
supplied 
-        // parent model
+        // If this component model has been asserted as a root model then it 
cannot
+        // have any non-optional dependencies. If the model is nested within 
another  
+        // model then we can attempt to resolve dependencies using the 
supplied enclosing 
+        // model and dependency directves declared in this model's profile. 
If a 
+        // dependency directive is not available and the dependency is 
required 
+        // (non-optional) then flag the model as unresolved. 
         //
 
         DependencyDescriptor[] dependencies = m_type.getDependencies();
@@ -128,17 +169,6 @@
         {
             DependencyDescriptor dependency = dependencies[i];
             boolean required = dependency.isRequired();
-            String key = dependency.getKey();
-            DependencyDirective directive = profile.getDependencyDirective( 
key );
-
-            if( ( null == directive ) && required )
-            {
-                final String error = 
-                  "Missing required dependency directive for the key ["
-                  + key 
-                  + "].";
-                throw new ModelException( error );
-            }
 
             if( null == parent )
             {
@@ -148,46 +178,71 @@
                       "The top-level component ["
                       + getQualifiedName()
                       + "] is declaring a required service dependency which 
logically cannot be resolved.";   
-                    throw new ModelException( error );
+                    throw new ModelRuntimeException( error );
+                }
+                else
+                {
+                    // ignore it as its optional and unresolvable
                 }
             }
             else
             {
-                Controller manager = parent.getController();
-                String path = directive.getSource();
-                Model model = manager.getProvider( parent, path );
-                if( null == model )
+                String key = dependency.getKey();
+                DependencyDirective directive = 
profile.getDependencyDirective( key );
+                if( null == directive )
                 {
-                    final String error = 
-                      "Unable to locate a service provider for the key ["
-                      + key 
-                      + "] in the component model ["
-                      + getQualifiedName()
-                      + "] using the source path ["
-                      + path
-                      + "].";
-                    throw new ModelException( error );
+                    if( required )
+                    {
+                        Exception e = new 
MissingDependencyDirectiveException( this, key );
+                        m_errors.add( e );
+                    }
                 }
                 else
                 {
-                    m_providers.put( key, model );
+                    Controller manager = parent.getController();
+                    String path = directive.getSource();
+                    Model model = manager.getProvider( parent, path );
+                    if( null == model )
+                    {
+                        final Exception e = new 
UnresolvableDependencyException( this, directive );
+                        m_errors.add( e );
+                    }
+                    else
+                    {
+                        m_providers.put( key, model );
+                    }
                 }
             }
         }
     }
 
+    public Throwable[] getIssues()
+    {
+        if( m_errors.isEmpty() )
+        {
+            return new Throwable[0];
+        }
+        else
+        {
+            return (Throwable[]) m_errors.toArray( new Throwable[ 0 ] );
+        }
+    }
+
     public Object create() throws Exception
     {
+        validate();
         return getController().create( this );
     }
 
     public Object resolve() throws Exception
     {
+        validate();
         return getController().resolve( this );
     }
 
     public Object resolve( Object key ) throws Exception
     {
+        validate();
         return getController().resolve( this, key );
     }
 
@@ -204,11 +259,10 @@
     public Model getPart( String spec )
     {
         //
-        // the following is rather limited - in particular we are 
+        // the following is too limited - in particular we are 
         // not handling paths in the form aaa/bbb/ccc
         //
-
-        return (Model) m_parts.get( spec ); 
+        return m_parts.getModel( spec );
     }
 
     public ClassLoader getClassLoader()
@@ -231,6 +285,18 @@
         return m_name;
     }
 
+    public void setName( String name )
+    {
+        if( null == name )
+        {
+            throw new NullPointerException( "name" );
+        }
+        if( false == name.equals( getName() ) )
+        {
+            m_name = name;
+        }
+    }
+
     public String getPartition()
     {
         return m_partition;
@@ -312,11 +378,7 @@
         }
         catch( ClassNotFoundException cnfe )
         {
-            final String error =
-              "Component implementation class [" 
-              + classname 
-              + "] not found.";
-            throw new ModelRuntimeException( error, cnfe );
+            throw new TypeClassNotFoundException( classname );
         }
     }
 
@@ -329,12 +391,21 @@
         }
         catch( ClassNotFoundException cnfe )
         {
-            final String error =
-              "Service interface class ["
-              + classname 
-              + "] not found.";
-            throw new ModelRuntimeException( error, cnfe );
+            String type = m_class.getName();
+            throw new ServiceClassNotFoundException( type, classname );
         }
     }
 
+    private void validate()
+    {
+        if( m_errors.isEmpty() )
+        {
+            return;
+        }
+        else
+        {
+            Throwable[] issues = getIssues();
+            throw new InvalidModelException( this, issues ); 
+        }
+    }
 }

Added: 
development/main/metro/composition/control/src/main/net/dpml/composition/models/UnresolvableDependencyException.java
==============================================================================
--- (empty file)
+++ 
development/main/metro/composition/control/src/main/net/dpml/composition/models/UnresolvableDependencyException.java
        Tue Apr  5 09:31:19 2005
@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2005 Stephen J. McConnell
+ *
+ * Licensed  under the  Apache License,  Version 2.0  (the "License");
+ * you may not use  this file  except in  compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed  under the  License is distributed on an "AS IS" BASIS,
+ * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY KIND, either  express  or
+ * implied.
+ *
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.dpml.composition.models;
+
+import net.dpml.automation.model.ModelException;
+
+import net.dpml.composition.data.DependencyDirective;
+
+/**
+ * Unexpected runtime exception indicating an internal model error.
+ *
+ * @author <a href="mailto:dev-dpml AT lists.ibiblio.org";>The Digital Product 
Meta Library</a>
+ * @version $Revision: 1.2 $ $Date: 2004/03/17 10:30:09 $
+ */
+public class  UnresolvableDependencyException extends ModelException 
+{
+    private StandardComponentModel m_model;
+    private DependencyDirective m_directive;
+
+    public UnresolvableDependencyException( StandardComponentModel model, 
DependencyDirective directive )
+    {
+        super( buildMessage( model, directive ) );
+        m_model = model;
+        m_directive = directive;
+    }
+
+    public DependencyDirective getDirective()
+    {
+        return m_directive;
+    }
+
+    public StandardComponentModel getModel()
+    {
+        return m_model;
+    }
+
+    private static String buildMessage( StandardComponentModel model, 
DependencyDirective directive )
+    {
+        final String name = model.getQualifiedName();
+        final String key = directive.getKey();
+        final String source = directive.getSource();
+        final String error =
+          "The source provider address ["
+          + source
+          + "] declared by the component model ["
+          + name
+          + "] under the dependency key ["
+          + key
+          + "] was not found.";
+        return error;
+    }
+}
+

Modified: 
development/main/metro/composition/testing/acme/src/main/net/dpml/composition/testing/AcmeContainer.java
==============================================================================
--- 
development/main/metro/composition/testing/acme/src/main/net/dpml/composition/testing/AcmeContainer.java
    (original)
+++ 
development/main/metro/composition/testing/acme/src/main/net/dpml/composition/testing/AcmeContainer.java
    Tue Apr  5 09:31:19 2005
@@ -56,25 +56,25 @@
     public AcmeContainer( final Logger logger, Parts parts )
     {
          m_logger = logger;
-         logger.info( "getting widget" );
+         logger.debug( "getting widget" );
          Widget widget = parts.getWidget();
 
-         logger.info( "getting gizmo" );
+         logger.debug( "getting gizmo" );
          Gizmo gizmo = parts.getGizmo();
 
-         logger.info( "getting gizmo impl" );
+         logger.debug( "getting gizmo impl" );
          DefaultGizmo newGizmo = parts.createGizmo();
 
-         logger.info( "getting identified gizmo" );
+         logger.debug( "getting identified gizmo" );
          Gizmo myGizmo = parts.getGizmo( "my-gizmo" );
 
-         logger.info( "releasing stuff" );
+         logger.debug( "releasing stuff" );
          parts.releaseGizmo( gizmo );
          parts.releaseGizmo( myGizmo );
          parts.releaseGizmo( newGizmo );
          parts.releaseWidget( widget );
 
-         logger.info( "done" );
+         logger.debug( "done" );
     }
 
     //------------------------------------------------------------------
@@ -83,7 +83,7 @@
 
     public void dispose()
     {
-        m_logger.info( "disposal" );
+        m_logger.debug( "disposal" );
     }
 
     public boolean equals( Object other )

Modified: 
development/main/metro/composition/testing/acme/src/main/net/dpml/composition/testing/DefaultGizmo.java
==============================================================================
--- 
development/main/metro/composition/testing/acme/src/main/net/dpml/composition/testing/DefaultGizmo.java
     (original)
+++ 
development/main/metro/composition/testing/acme/src/main/net/dpml/composition/testing/DefaultGizmo.java
     Tue Apr  5 09:31:19 2005
@@ -63,7 +63,7 @@
         m_logger = logger;
         Widget widget = dependencies.getWidget();
         widget.doWidgetTypeStuff();
-        logger.info( "ready");
+        logger.debug( "ready");
     }
 
     //------------------------------------------------------------------
@@ -72,7 +72,7 @@
 
     public void dispose()
     {
-        m_logger.info( "disposal" );
+        m_logger.debug( "disposal" );
     }
 
     //------------------------------------------------------------------

Modified: 
development/main/metro/composition/testing/acme/src/main/net/dpml/composition/testing/DefaultWidget.java
==============================================================================
--- 
development/main/metro/composition/testing/acme/src/main/net/dpml/composition/testing/DefaultWidget.java
    (original)
+++ 
development/main/metro/composition/testing/acme/src/main/net/dpml/composition/testing/DefaultWidget.java
    Tue Apr  5 09:31:19 2005
@@ -80,7 +80,7 @@
         String partition = m_context.getPartition();
         File work = m_context.getWorkingDirectory();
 
-        m_logger.info( "widget created" );
+        m_logger.debug( "widget created" );
     }
 
     //------------------------------------------------------------------
@@ -110,7 +110,7 @@
     */
     public void dispose()
     {
-        m_logger.info( "disposal" );
+        m_logger.debug( "disposal" );
     }
 
    /**
@@ -137,7 +137,7 @@
         int width = m_context.getWidth();
         int height = m_context.getHeight( 5024 );
 
-        m_logger.info( 
+        m_logger.debug( 
           name 
           + " established with a width of " 
           + width