DPML Notify

[mcconnell at BerliOS <mcconnell AT mail.berlios.de>]

Author: mcconnell
Date: 2006-03-03 21:33:07 +0100 (Fri, 03 Mar 2006)
New Revision: 1165

Added:
   trunk/lab/lang/src/main/dpmlx/schema/PartHandlerFactory.java
   trunk/main/transit/core/src/main/net/dpml/part/
   trunk/main/transit/core/src/main/net/dpml/part/PartHandler.java
   trunk/main/transit/core/src/main/net/dpml/part/StandardPartHandler.java
Removed:
   trunk/lab/lang/src/main/dpmlx/lang/PartHandler.java
   trunk/lab/lang/src/main/dpmlx/schema/PluginPartHandler.java
Modified:
   trunk/lab/component/src/main/dpmlx/component/ComponentStrategyBuilder.java
   trunk/lab/lang/src/main/dpmlx/lang/PartDirective.java
   trunk/lab/lang/src/main/dpmlx/schema/DOMDocumentBuilder.java
   trunk/lab/lang/src/main/dpmlx/schema/PartStrategyBuilder.java
   trunk/lab/lang/src/main/dpmlx/schema/Plugin.java
   trunk/lab/library.xml
   trunk/lab/test/build.xml
   trunk/lab/test/etc/test/component.xml
   trunk/lab/test/src/test/dpmlx/schema/test/SchemaTestCase.java
   
trunk/main/metro/runtime/src/main/net/dpml/metro/runtime/CompositionController.java
   trunk/main/transit/core/src/main/net/dpml/transit/StandardClassLoader.java
Log:
first steps in moving combined plugin/part model into trunk

Modified: 
trunk/lab/component/src/main/dpmlx/component/ComponentStrategyBuilder.java
===================================================================
--- 
trunk/lab/component/src/main/dpmlx/component/ComponentStrategyBuilder.java  
2006-03-03 17:34:30 UTC (rev 1164)
+++ 
trunk/lab/component/src/main/dpmlx/component/ComponentStrategyBuilder.java  
2006-03-03 20:33:07 UTC (rev 1165)
@@ -22,7 +22,8 @@
 
 import net.dpml.metro.data.ComponentDirective;
 
-import net.dpml.transit.info.ValueDirective;
+import net.dpml.transit.Value;
+import net.dpml.transit.Construct;
 import net.dpml.transit.util.ElementHelper;
 
 import dpmlx.lang.Strategy;
@@ -105,35 +106,35 @@
             String spec = ElementHelper.getAttribute( element, "uri" );
             URI uri = new URI( spec );
             Element[] elements = ElementHelper.getChildren( element, "param" 
);
-            ValueDirective[] values = createValueDirectives( elements );
+            Value[] values = createValues( elements );
             return new PartDirective( uri, values );
         }
     }
 
-    private ValueDirective[] createValueDirectives( Element[] elements )
+    private Value[] createValues( Element[] elements )
     {
-        ValueDirective[] values = new ValueDirective[ elements.length ];
+        Value[] values = new Value[ elements.length ];
         for( int i=0; i<elements.length; i++ )
         {
-            values[i] = createValueDirective( elements[i] );
+            values[i] = createValue( elements[i] );
         }
         return values;
     }
     
-    private ValueDirective createValueDirective( Element element )
+    private Value createValue( Element element )
     {
         String classname = ElementHelper.getAttribute( element, "class" );
         String method = ElementHelper.getAttribute( element, "method" );
         Element[] elements = ElementHelper.getChildren( element, "param" );
         if( elements.length > 0 )
         {
-            ValueDirective[] values = createValueDirectives( elements );
-            return new ValueDirective( classname, method, values );
+            Value[] values = createValues( elements );
+            return new Construct( classname, method, values );
         }
         else
         {
             String value = ElementHelper.getAttribute( element, "value" );
-            return new ValueDirective( classname, method, value );
+            return new Construct( classname, method, value );
         }
     }
 }

Modified: trunk/lab/lang/src/main/dpmlx/lang/PartDirective.java
===================================================================
--- trunk/lab/lang/src/main/dpmlx/lang/PartDirective.java       2006-03-03 
17:34:30 UTC (rev 1164)
+++ trunk/lab/lang/src/main/dpmlx/lang/PartDirective.java       2006-03-03 
20:33:07 UTC (rev 1165)
@@ -21,7 +21,7 @@
 import java.io.Serializable;
 import java.net.URI;
 
-import net.dpml.transit.info.ValueDirective;
+import net.dpml.transit.Value;
 
 /**
  * Immutable part creation directive.
@@ -32,9 +32,9 @@
 public final class PartDirective implements Serializable
 {
     private final URI m_uri;
-    private final ValueDirective[] m_params;
+    private final Value[] m_params;
     
-    public PartDirective( URI uri, ValueDirective[] params )
+    public PartDirective( URI uri, Value[] params )
     {
         if( null == uri )
         {
@@ -43,7 +43,7 @@
         m_uri = uri;
         if( null == params )
         {
-            m_params = new ValueDirective[0];
+            m_params = new Value[0];
         }
         else
         {
@@ -64,7 +64,7 @@
     * Get the values to be used during part instantiation.
     * @return the directives
     */
-    public ValueDirective[] getValueDirectives()
+    public Value[] getValues()
     {
         return m_params;
     }

Deleted: trunk/lab/lang/src/main/dpmlx/lang/PartHandler.java
===================================================================
--- trunk/lab/lang/src/main/dpmlx/lang/PartHandler.java 2006-03-03 17:34:30 
UTC (rev 1164)
+++ trunk/lab/lang/src/main/dpmlx/lang/PartHandler.java 2006-03-03 20:33:07 
UTC (rev 1165)
@@ -1,44 +0,0 @@
-/*
- * Copyright 2006 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 dpmlx.lang;
-
-import net.dpml.lang.Classpath;
-
-/**
- * Interface implemented by part runtime handlers. Handler are identified
- * by the uri returned from the <tt>Part.getStrategy().getController()</tt>.
- */
-public interface PartHandler
-{
-   /**
-    * Build a classloader stack.
-    * @param anchor the anchor classloader to server as the classloader 
chain root
-    * @param classpath the part classpath definition
-    */
-    ClassLoader getClassLoader( ClassLoader anchor, Classpath classpath );
-
-   /**
-    * Instantiate a value.
-    * @param classloader the implementation classloader established for the 
part
-    * @param data the part deployment data
-    * @param args supplimentary arguments
-    * @exception Exception if a deployment error occurs
-    */
-    Object getInstance( ClassLoader classloader, Object data, Object[] args 
) throws Exception;
-}

Modified: trunk/lab/lang/src/main/dpmlx/schema/DOMDocumentBuilder.java
===================================================================
--- trunk/lab/lang/src/main/dpmlx/schema/DOMDocumentBuilder.java        
2006-03-03 17:34:30 UTC (rev 1164)
+++ trunk/lab/lang/src/main/dpmlx/schema/DOMDocumentBuilder.java        
2006-03-03 20:33:07 UTC (rev 1165)
@@ -38,7 +38,6 @@
 import org.xml.sax.SAXNotSupportedException;
 import org.xml.sax.SAXParseException;
 import org.xml.sax.XMLReader;
-//import org.xml.sax.helpers.DefaultHandler;
 
 import org.w3c.dom.Document;
 

Added: trunk/lab/lang/src/main/dpmlx/schema/PartHandlerFactory.java
===================================================================
--- trunk/lab/lang/src/main/dpmlx/schema/PartHandlerFactory.java        
2006-03-03 17:34:30 UTC (rev 1164)
+++ trunk/lab/lang/src/main/dpmlx/schema/PartHandlerFactory.java        
2006-03-03 20:33:07 UTC (rev 1165)
@@ -0,0 +1,121 @@
+/*
+ * Copyright 2006 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 dpmlx.schema;
+
+import java.io.IOException;
+import java.net.URI;
+import java.util.Hashtable;
+
+import dpmlx.lang.PartDirective;
+
+import net.dpml.lang.Classpath;
+import net.dpml.part.PartHandler;
+import net.dpml.part.StandardPartHandler;
+
+import net.dpml.transit.Transit;
+import net.dpml.transit.Repository;
+import net.dpml.transit.Value;
+import net.dpml.transit.Construct;
+
+
+/**
+ * Factory used to locate part handlers.
+ */
+public class PartHandlerFactory
+{
+    private static final StandardPartHandler HANDLER = new 
StandardPartHandler();
+    
+    private Hashtable m_map = new Hashtable();
+    
+    private static final PartHandlerFactory FACTORY = new 
PartHandlerFactory();
+    
+    public static PartHandlerFactory getInstance()
+    {
+        return FACTORY;
+    }
+    
+    private PartHandlerFactory()
+    {
+    }
+    
+   /**
+    * Locate or resolve a part handler.
+    * @param uri the part uri
+    * @param args part instantiation arguments
+    * @exception Exception if an error occurs during handler resolution
+    */
+    public PartHandler getPartHandler( PartDirective directive ) throws 
Exception
+    {
+        URI uri = directive.getURI();
+        Value[] params = directive.getValues();
+        Object[] args = Construct.getArgs( null, params, new Object[0] );
+        return getPartHandler( uri, args );
+    }
+    
+   /**
+    * Locate or resolve a part handler.
+    * @param uri the part uri
+    * @param args part instantiation arguments
+    * @exception Exception if an error occurs during handler resolution
+    */
+    public PartHandler getPartHandler( URI uri, Object[] args ) throws 
Exception
+    {
+        if( StandardPartHandler.PART_HANDLER_URI.equals( uri ) )
+        {
+            return HANDLER;
+        }
+        else
+        {
+            synchronized( m_map )
+            {
+                if( m_map.containsKey( uri ) )
+                {
+                    return (PartHandler) m_map.get( uri );
+                }
+                else
+                {
+                    PartHandler handler = loadPartHandler( uri, args );
+                    m_map.put( uri, handler );
+                    return handler;
+                }
+            }
+        }
+    }
+    
+    private PartHandler loadPartHandler( URI uri, Object[] args ) throws 
Exception
+    {
+        ClassLoader classloader = PartHandler.class.getClassLoader();
+        Repository repository = Transit.getInstance().getRepository();
+        Object instance = repository.getPlugin( classloader, uri, args );
+        if( instance instanceof PartHandler )
+        {
+            return (PartHandler) instance;
+        }
+        else
+        {
+            final String error =
+              "Plugin uri does not resolve to an instance of "
+              + PartHandler.class.getName()
+              + "."
+              + "\nURI: " + uri 
+              + "\nCLass: " + instance.getClass().getName();
+            throw new IllegalArgumentException( error );
+        }
+    }
+}

Modified: trunk/lab/lang/src/main/dpmlx/schema/PartStrategyBuilder.java
===================================================================
--- trunk/lab/lang/src/main/dpmlx/schema/PartStrategyBuilder.java       
2006-03-03 17:34:30 UTC (rev 1164)
+++ trunk/lab/lang/src/main/dpmlx/schema/PartStrategyBuilder.java       
2006-03-03 20:33:07 UTC (rev 1165)
@@ -25,8 +25,10 @@
 import dpmlx.lang.StrategyBuilder;
 import dpmlx.lang.PartDirective;
 
-import net.dpml.transit.info.ValueDirective;
+import net.dpml.transit.Value;
+import net.dpml.transit.Construct;
 import net.dpml.transit.util.ElementHelper;
+import net.dpml.part.StandardPartHandler;
 
 import org.w3c.dom.TypeInfo;
 import org.w3c.dom.Element;
@@ -39,7 +41,8 @@
  */
 public class PartStrategyBuilder implements StrategyBuilder
 {
-    private static final PartDirective TRANSIT_DIRECTIVE = 
createTransitDirective();
+    private static final PartDirective TRANSIT_DIRECTIVE = 
+      new PartDirective( StandardPartHandler.PART_HANDLER_URI, null );
     
     public Strategy buildStrategy( Element element ) throws Exception
     {
@@ -56,7 +59,7 @@
         {
             String classname = ElementHelper.getAttribute( element, "class" 
);
             Element[] elements = ElementHelper.getChildren( element, "param" 
);
-            ValueDirective[] values = createValueDirectives( elements );
+            Value[] values = createValues( elements );
             Plugin plugin = new Plugin( classname, values );
             return new Strategy( TRANSIT_DIRECTIVE, plugin );
         }
@@ -79,44 +82,30 @@
         }
     }
     
-    private ValueDirective[] createValueDirectives( Element[] elements )
+    private Value[] createValues( Element[] elements )
     {
-        ValueDirective[] values = new ValueDirective[ elements.length ];
+        Value[] values = new Value[ elements.length ];
         for( int i=0; i<elements.length; i++ )
         {
-            values[i] = createValueDirective( elements[i] );
+            values[i] = createValue( elements[i] );
         }
         return values;
     }
     
-    private ValueDirective createValueDirective( Element element )
+    private Value createValue( Element element )
     {
         String classname = ElementHelper.getAttribute( element, "class" );
         String method = ElementHelper.getAttribute( element, "method" );
         Element[] elements = ElementHelper.getChildren( element, "param" );
         if( elements.length > 0 )
         {
-            ValueDirective[] values = createValueDirectives( elements );
-            return new ValueDirective( classname, method, values );
+            Value[] values = createValues( elements );
+            return new Construct( classname, method, values );
         }
         else
         {
             String value = ElementHelper.getAttribute( element, "value" );
-            return new ValueDirective( classname, method, value );
+            return new Construct( classname, method, value );
         }
     }
-    
-    private static PartDirective createTransitDirective()
-    {
-        try
-        {
-            URI uri = new URI( "internal:transit" );
-            return new PartDirective( uri, null );
-        }
-        catch( Throwable e )
-        {
-            e.printStackTrace();
-            return null;
-        }
-    }
 }

Modified: trunk/lab/lang/src/main/dpmlx/schema/Plugin.java
===================================================================
--- trunk/lab/lang/src/main/dpmlx/schema/Plugin.java    2006-03-03 17:34:30 
UTC (rev 1164)
+++ trunk/lab/lang/src/main/dpmlx/schema/Plugin.java    2006-03-03 20:33:07 
UTC (rev 1165)
@@ -21,14 +21,14 @@
 import java.io.Serializable;
 import java.util.Arrays;
 
-import net.dpml.transit.info.ValueDirective;
+import net.dpml.transit.Value;
 
 class Plugin implements Serializable
 {
     private final String m_classname;
-    private final ValueDirective[] m_params;
+    private final Value[] m_params;
     
-    public Plugin( String classname, ValueDirective[] params )
+    public Plugin( String classname, Value[] params )
     {
         m_classname = classname;
         m_params = params;
@@ -39,7 +39,7 @@
         return m_classname;
     }
     
-    public ValueDirective[] getValueDirectives()
+    public Value[] getValues()
     {
         return m_params;
     }

Deleted: trunk/lab/lang/src/main/dpmlx/schema/PluginPartHandler.java
===================================================================
--- trunk/lab/lang/src/main/dpmlx/schema/PluginPartHandler.java 2006-03-03 
17:34:30 UTC (rev 1164)
+++ trunk/lab/lang/src/main/dpmlx/schema/PluginPartHandler.java 2006-03-03 
20:33:07 UTC (rev 1165)
@@ -1,53 +0,0 @@
-/*
- * Copyright 2006 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 dpmlx.schema;
-
-import java.io.Serializable;
-
-import net.dpml.lang.Classpath;
-
-import dpmlx.lang.PartHandler;
-
-/**
- * Construct a part.
- */
-public class PluginPartHandler implements PartHandler
-{
-   /**
-    * Build a classloader stack.
-    * @param anchor the anchor classloader to server as the classloader 
chain root
-    * @param classpath the part classpath definition
-    */
-    public ClassLoader getClassLoader( ClassLoader anchor, Classpath 
classpath )
-    {
-        throw new UnsupportedOperationException( "getClassLoader" );
-    }
-
-   /**
-    * Instantiate a value.
-    * @param classloader the implementation classloader established for the 
part
-    * @param data the part deployment data
-    * @param args supplimentary arguments
-    * @exception Exception if a deployment error occurs
-    */
-    public Object getInstance( ClassLoader classloader, Object data, 
Object[] args ) throws Exception
-    {
-        throw new UnsupportedOperationException( "getInstance" );
-    }
-}

Modified: trunk/lab/library.xml
===================================================================
--- trunk/lab/library.xml       2006-03-03 17:34:30 UTC (rev 1164)
+++ trunk/lab/library.xml       2006-03-03 20:33:07 UTC (rev 1165)
@@ -60,6 +60,7 @@
           <dependencies scope="test">
             <include key="dpmlx-lang"/>
             <include ref="ant/ant-junit"/>
+            <include ref="dpml/metro/dpml-part-api"/>
           </dependencies>
         </project>
     

Modified: trunk/lab/test/build.xml
===================================================================
--- trunk/lab/test/build.xml    2006-03-03 17:34:30 UTC (rev 1164)
+++ trunk/lab/test/build.xml    2006-03-03 20:33:07 UTC (rev 1165)
@@ -9,6 +9,7 @@
   <target name="init" depends="standard.init">
     <x:filter feature="uri" type="xsd" token="COMPONENT-XSD-URI" 
ref="dpmlx/dpmlx-component"/>
     <x:filter feature="uri" type="xsd" token="PART-XSD-URI" 
ref="dpmlx/dpmlx-part"/>
+    <x:filter feature="uri" type="plugin" token="METRO-CONTROLLER-URI" 
ref="dpml/metro/dpml-metro-runtime"/>
   </target>
 
 </project>

Modified: trunk/lab/test/etc/test/component.xml
===================================================================
--- trunk/lab/test/etc/test/component.xml       2006-03-03 17:34:30 UTC (rev 
1164)
+++ trunk/lab/test/etc/test/component.xml       2006-03-03 20:33:07 UTC (rev 
1165)
@@ -15,6 +15,9 @@
   </info>
   
   <strategy xsi:type="component:definition">
+    <controller xmlns="@COMPONENT-XSD-URI@" uri="@METRO-CONTROLLER-URI@" >
+      <param class="net.dpml.part.InitialContext"/>
+    </controller>
     <component xmlns="@COMPONENT-XSD-URI@" class="org.acme.Widget" >
       <context>
         <entry key="foo" value="abc"/>

Modified: trunk/lab/test/src/test/dpmlx/schema/test/SchemaTestCase.java
===================================================================
--- trunk/lab/test/src/test/dpmlx/schema/test/SchemaTestCase.java       
2006-03-03 17:34:30 UTC (rev 1164)
+++ trunk/lab/test/src/test/dpmlx/schema/test/SchemaTestCase.java       
2006-03-03 20:33:07 UTC (rev 1165)
@@ -10,7 +10,10 @@
 import dpmlx.lang.PartDirective;
 import dpmlx.schema.PartBuilder;
 import dpmlx.schema.UnresolvableHandlerException;
+import dpmlx.schema.PartHandlerFactory;
 
+import net.dpml.part.PartHandler;
+
 import junit.framework.TestCase;
 
 import org.w3c.dom.Document;
@@ -64,5 +67,15 @@
         
         System.out.println( "  Controller: " + uri );
         System.out.println( "  Data: " + data.getClass().getName() );
+        
+        try
+        {
+            PartHandler handler = 
PartHandlerFactory.getInstance().getPartHandler( directive );
+            System.out.println( "  Handler: " + handler );
+        }
+        catch( Throwable e )
+        {
+            System.out.println( "  " + e.toString() );
+        }
     }
 }

Modified: 
trunk/main/metro/runtime/src/main/net/dpml/metro/runtime/CompositionController.java
===================================================================
--- 
trunk/main/metro/runtime/src/main/net/dpml/metro/runtime/CompositionController.java
 2006-03-03 17:34:30 UTC (rev 1164)
+++ 
trunk/main/metro/runtime/src/main/net/dpml/metro/runtime/CompositionController.java
 2006-03-03 20:33:07 UTC (rev 1165)
@@ -45,6 +45,9 @@
 import net.dpml.part.Model;
 import net.dpml.part.Component;
 
+import net.dpml.part.PartHandler;
+import net.dpml.part.StandardPartHandler;
+
 import net.dpml.transit.Repository;
 import net.dpml.transit.Transit;
 
@@ -55,7 +58,7 @@
  * @author <a href="@PUBLISHER-URL@">@PUBLISHER-NAME@</a>
  * @version @PROJECT-VERSION@
  */
-public class CompositionController implements Controller
+public class CompositionController extends StandardPartHandler implements 
Controller
 {
     //--------------------------------------------------------------------
     // immutable state
@@ -100,6 +103,10 @@
     }
     
     //--------------------------------------------------------------------
+    // PartHandler
+    //--------------------------------------------------------------------
+    
+    //--------------------------------------------------------------------
     // Controller
     //--------------------------------------------------------------------
     

Added: trunk/main/transit/core/src/main/net/dpml/part/PartHandler.java
===================================================================
--- trunk/main/transit/core/src/main/net/dpml/part/PartHandler.java     
2006-03-03 17:34:30 UTC (rev 1164)
+++ trunk/main/transit/core/src/main/net/dpml/part/PartHandler.java     
2006-03-03 20:33:07 UTC (rev 1165)
@@ -0,0 +1,47 @@
+/*
+ * Copyright 2006 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.part;
+
+import java.io.IOException;
+
+import net.dpml.lang.Classpath;
+
+/**
+ * Interface implemented by part runtime handlers. Handler are identified
+ * by the uri returned from the <tt>Part.getStrategy().getController()</tt>.
+ */
+public interface PartHandler
+{
+   /**
+    * Build a classloader stack.
+    * @param anchor the anchor classloader to server as the classloader 
chain root
+    * @param classpath the part classpath definition
+    * @exception IOException if an IO error occurs during classpath 
evaluation
+    */
+    ClassLoader getClassLoader( ClassLoader anchor, Classpath classpath ) 
throws IOException;
+
+   /**
+    * Instantiate a value.
+    * @param classloader the implementation classloader established for the 
part
+    * @param data the part deployment data
+    * @param args supplimentary arguments
+    * @exception Exception if a deployment error occurs
+    */
+    Object getInstance( ClassLoader classloader, Object data, Object[] args 
) throws Exception;
+}

Added: trunk/main/transit/core/src/main/net/dpml/part/StandardPartHandler.java
===================================================================
--- trunk/main/transit/core/src/main/net/dpml/part/StandardPartHandler.java   
  2006-03-03 17:34:30 UTC (rev 1164)
+++ trunk/main/transit/core/src/main/net/dpml/part/StandardPartHandler.java   
  2006-03-03 20:33:07 UTC (rev 1165)
@@ -0,0 +1,187 @@
+/*
+ * Copyright 2006 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.part;
+
+import java.net.URI;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.util.ArrayList;
+import java.io.IOException;
+
+import net.dpml.lang.Category;
+import net.dpml.lang.Classpath;
+
+import net.dpml.transit.Artifact;
+import net.dpml.transit.StandardClassLoader;
+
+/**
+ * Construct a part.
+ */
+public class StandardPartHandler implements PartHandler
+{
+    public static final URI PART_HANDLER_URI = createHandlerURI();
+    
+   /**
+    * Build a classloader stack.
+    * @param anchor the anchor classloader to server as the classloader 
chain root
+    * @param classpath the part classpath definition
+    */
+    public ClassLoader getClassLoader( ClassLoader anchor, Classpath 
classpath ) throws IOException
+    {
+        if( null == anchor )
+        {
+            throw new NullPointerException( "anchor" );
+        }
+        if( null == classpath )
+        {
+            throw new NullPointerException( "classpath" );
+        }
+        
+        URL[] sysUrls = getURLs( classpath, Category.SYSTEM );
+        URL[] apis = getURLs( classpath, Category.PUBLIC );
+        URL[] spis = getURLs( classpath, Category.PROTECTED );
+        URL[] imps = getURLs( classpath, Category.PRIVATE );
+        //if( sysUrls.length > 0 )
+        //{
+        //    updateSystemClassLoader( plugin, sysUrls );
+        //}
+        
+        ClassLoader parent = buildClassLoader( Category.PUBLIC, anchor, apis 
);
+        parent = buildClassLoader( Category.PROTECTED, parent, spis );
+        parent = buildClassLoader( Category.PRIVATE, parent, imps );
+        return parent;
+    }
+    
+   /**
+    * Instantiate a value.
+    * @param classloader the implementation classloader established for the 
part
+    * @param data the part deployment data
+    * @param args supplimentary arguments
+    * @exception Exception if a deployment error occurs
+    */
+    public Object getInstance( ClassLoader classloader, Object data, 
Object[] args ) throws Exception
+    {
+        throw new UnsupportedOperationException( "getInstance" );
+    }
+    
+    private URL[] getURLs( Classpath classpath, Category category ) throws 
IOException
+    {
+        URI[] uris = classpath.getDependencies( category );
+        return getURLs( uris );
+    }
+
+   /**
+    * Convert a sequncence of URIs to URLs.
+    * @param uris the uris to convert
+    * @return the corresponding urls
+    * @exception IOException of a transformation error occurs
+    */
+    private URL[] getURLs( URI[] uris ) throws IOException
+    {
+        URL[] urls = new URL[ uris.length ];
+        for( int i=0; i < urls.length; i++ )
+        {
+            URI uri = uris[i];
+            urls[i] = Artifact.toURL( uri );
+        }
+        return urls;
+    }
+    
+   /**
+    * Internal utility class to build a classloader.  If the supplied url
+    * sequence is zero length the parent classloader is returned directly.
+    *
+    * @param category the type of classloader (api, spi, impl)
+    * @param parent the parent classloader
+    * @param urls the urls to assign as classloader content
+    * @return the classloader
+    */
+    private ClassLoader buildClassLoader( Category category, ClassLoader 
parent, URL[] urls )
+    {
+        if( 0 == urls.length )
+        {
+            return parent;
+        }
+        ArrayList list = new ArrayList();
+        for( int i=0; i < urls.length; i++ )
+        {
+            if( isaCandidate( parent, urls[i] ) )
+            {
+                list.add( urls[i] );
+            }
+        }
+        URL[] qualified = (URL[]) list.toArray( new URL[0] );
+        if( qualified.length == 0 )
+        {
+            return parent;
+        }
+        else
+        {
+            return new StandardClassLoader( null, category, qualified, 
parent );
+        }
+    }
+
+   /**
+    * Test if the supplied url is already present within the supplied 
classloader.
+    * @param classloader the classloader to validate against
+    * @param url to url to check for
+    * @return true if the url is not included in the classloader
+    */
+    private boolean isaCandidate( ClassLoader classloader, URL url )
+    {
+        if( classloader instanceof URLClassLoader )
+        {
+            URL[] urls = ( (URLClassLoader) classloader ).getURLs();
+            for( int i=0; i < urls.length; i++ )
+            {
+                if( urls[i].equals( url ) )
+                {
+                    return false;
+                }
+            }
+            ClassLoader parent = classloader.getParent();
+            if( parent == null )
+            {
+                return true;
+            }
+            else
+            {
+                return isaCandidate( parent, url );
+            }
+        }
+        else
+        {
+            return true;
+        }
+    }
+    
+    private static URI createHandlerURI()
+    {
+        try
+        {
+            return new URI( "internal:transit" );
+        }
+        catch( Throwable e )
+        {
+            e.printStackTrace();
+            return null;
+        }
+    }
+    
+}

Modified: 
trunk/main/transit/core/src/main/net/dpml/transit/StandardClassLoader.java
===================================================================
--- 
trunk/main/transit/core/src/main/net/dpml/transit/StandardClassLoader.java  
2006-03-03 17:34:30 UTC (rev 1164)
+++ 
trunk/main/transit/core/src/main/net/dpml/transit/StandardClassLoader.java  
2006-03-03 20:33:07 UTC (rev 1165)
@@ -193,7 +193,14 @@
                 listClasspath( buffer, parent );
             }
 
-            label = label.concat( "\nGroup: " + m_plugin + " " + 
cl.getCategory() );
+            if( null != m_plugin )
+            {
+                label = label.concat( "\nGroup: " + m_plugin + " " + 
cl.getCategory() );
+            }
+            else
+            {
+                label = label.concat( "\nCategory: " + cl.getCategory() );
+            }
             buffer.append( label );
             buffer.append( "\n" );
             appendEntries( buffer, cl );