Changes to DefaultDeployer:

* Parses services descriptors (META-INF/ant-services.xml).  Does not do anything
  with them yet.

* Enforces that the version attribute in type, role, and service descriptors
  is present, and compatible with the current version.

* Moved descriptor construction from DefaultDeployer into separate
  DescriptorBuilder classes, one for each type of descriptor.

* Detection of whether a descriptor is present in a file, was not portable across
  XML parser implementations.


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@271294 13f79535-47bb-0310-9956-ffa450edef68

proposal/myrmidon/src/java/org/apache/myrmidon/components/deployer/ClassLoaderManager.java

@@ -8,8 +8,8 @@
 package org.apache.myrmidon.components.deployer;
 
 import java.io.File;
-import org.apache.myrmidon.interfaces.deployer.DeploymentException;
 import org.apache.avalon.framework.component.Component;
+import org.apache.myrmidon.interfaces.deployer.DeploymentException;
 
 /**
  * Manages a classloader hierarchy.

proposal/myrmidon/src/java/org/apache/myrmidon/components/deployer/DefaultDeployer.java

@@ -17,23 +17,22 @@ import org.apache.avalon.framework.component.ComponentException;
 import org.apache.avalon.framework.component.ComponentManager;
 import org.apache.avalon.framework.component.Composable;
 import org.apache.avalon.framework.logger.AbstractLogEnabled;
-import org.apache.avalon.framework.configuration.Configuration;
-import org.apache.avalon.framework.configuration.ConfigurationException;
+import org.apache.myrmidon.converter.Converter;
+import org.apache.myrmidon.interfaces.converter.ConverterRegistry;
+import org.apache.myrmidon.interfaces.deployer.ConverterDefinition;
 import org.apache.myrmidon.interfaces.deployer.Deployer;
 import org.apache.myrmidon.interfaces.deployer.DeploymentException;
-import org.apache.myrmidon.interfaces.deployer.TypeDeployer;
 import org.apache.myrmidon.interfaces.deployer.TypeDefinition;
-import org.apache.myrmidon.interfaces.deployer.ConverterDefinition;
-import org.apache.myrmidon.interfaces.converter.ConverterRegistry;
-import org.apache.myrmidon.interfaces.type.TypeManager;
-import org.apache.myrmidon.interfaces.type.DefaultTypeFactory;
+import org.apache.myrmidon.interfaces.deployer.TypeDeployer;
 import org.apache.myrmidon.interfaces.role.RoleManager;
-import org.apache.myrmidon.converter.Converter;
+import org.apache.myrmidon.interfaces.type.DefaultTypeFactory;
+import org.apache.myrmidon.interfaces.type.TypeManager;
 
 /**
  * This class deploys roles, types and services from a typelib.
  *
  * @author <a href="mailto:peter@apache.org">Peter Donald</a>
+ * @author <a href="mailto:adammurdoch@apache.org">Adam Murdoch</a>
  * @version $Revision$ $Date$
  */
 public class DefaultDeployer
@@ -136,57 +135,10 @@ public class DefaultDeployer
         return deployment;
     }
 
-    /**
-     * Creates a type definition.
-     */
-    public TypeDefinition createTypeDefinition( final Configuration configuration )
-        throws ConfigurationException
-    {
-        final String converterShorthand = m_roleManager.getNameForRole( Converter.ROLE );
-        final String roleShorthand = configuration.getName();
-        if( roleShorthand.equals( converterShorthand ) )
-        {
-            // A converter definition
-            final String className = configuration.getAttribute( "classname" );
-            final String source = configuration.getAttribute( "source" );
-            final String destination = configuration.getAttribute( "destination" );
-            return new ConverterDefinition( className, source, destination );
-        }
-        else
-        {
-            // A type definition
-            final String typeName = configuration.getAttribute( "name" );
-            final String className = configuration.getAttribute( "classname" );
-            return new TypeDefinition( typeName, roleShorthand, className );
-        }
-    }
-
-    /**
-     * Handles a converter definition.
-     */
-    private void handleConverter( final Deployment deployment,
-                                  final String className,
-                                  final String source,
-                                  final String destination )
-        throws Exception
-    {
-        m_converterRegistry.registerConverter( className, source, destination );
-        final DefaultTypeFactory factory = deployment.getFactory( Converter.class );
-        factory.addNameClassMapping( className, className );
-        m_typeManager.registerType( Converter.class, className, factory );
-
-        if( getLogger().isDebugEnabled() )
-        {
-            final String message =
-                REZ.getString( "register-converter.notice", source, destination );
-            getLogger().debug( message );
-        }
-    }
-
     /**
      * Handles a type definition.
      */
-    public void handleType( final Deployment deployment,
+    public void deployType( final Deployment deployment,
                             final TypeDefinition typeDef )
         throws Exception
     {
@@ -263,10 +215,32 @@ public class DefaultDeployer
         }
     }
 
+    /**
+     * Handles a converter definition.
+     */
+    private void handleConverter( final Deployment deployment,
+                                  final String className,
+                                  final String source,
+                                  final String destination )
+        throws Exception
+    {
+        m_converterRegistry.registerConverter( className, source, destination );
+        final DefaultTypeFactory factory = deployment.getFactory( Converter.class );
+        factory.addNameClassMapping( className, className );
+        m_typeManager.registerType( Converter.class, className, factory );
+
+        if( getLogger().isDebugEnabled() )
+        {
+            final String message =
+                REZ.getString( "register-converter.notice", source, destination );
+            getLogger().debug( message );
+        }
+    }
+
     /**
      * Handles a role definition.
      */
-    public void handleRole( final Deployment deployment,
+    public void deployRole( final Deployment deployment,
                             final RoleDefinition roleDef )
     {
         final String name = roleDef.getShortHand();

proposal/myrmidon/src/java/org/apache/myrmidon/components/deployer/Deployment.java

@@ -12,34 +12,24 @@ import java.net.URL;
 import java.util.ArrayList;
 import java.util.Enumeration;
 import java.util.HashMap;
-import java.util.Iterator;
-import java.util.List;
 import java.util.Map;
 import javax.xml.parsers.SAXParser;
 import javax.xml.parsers.SAXParserFactory;
 import org.apache.avalon.excalibur.i18n.ResourceManager;
 import org.apache.avalon.excalibur.i18n.Resources;
-import org.apache.avalon.framework.component.ComponentException;
-import org.apache.avalon.framework.component.ComponentManager;
-import org.apache.avalon.framework.configuration.Configuration;
-import org.apache.avalon.framework.configuration.ConfigurationException;
 import org.apache.avalon.framework.configuration.SAXConfigurationHandler;
 import org.apache.avalon.framework.logger.AbstractLogEnabled;
-import org.apache.myrmidon.converter.Converter;
-import org.apache.myrmidon.interfaces.converter.ConverterRegistry;
-import org.apache.myrmidon.interfaces.deployer.ConverterDefinition;
 import org.apache.myrmidon.interfaces.deployer.DeploymentException;
 import org.apache.myrmidon.interfaces.deployer.TypeDefinition;
 import org.apache.myrmidon.interfaces.deployer.TypeDeployer;
-import org.apache.myrmidon.interfaces.role.RoleManager;
 import org.apache.myrmidon.interfaces.type.DefaultTypeFactory;
-import org.apache.myrmidon.interfaces.type.TypeManager;
 import org.xml.sax.XMLReader;
 
 /**
  * This class deploys type libraries from a ClassLoader into a registry.
  *
  * @author <a href="mailto:peter@apache.org">Peter Donald</a>
+ * @author <a href="mailto:adammurdoch@apache.org">Adam Murdoch</a>
  * @version $Revision$ $Date$
  */
 class Deployment
@@ -49,13 +39,19 @@ class Deployment
     private final static Resources REZ =
         ResourceManager.getPackageResources( Deployment.class );
 
-    private final static String DESCRIPTOR_NAME = "META-INF/ant-descriptor.xml";
+    private final static String TYPE_DESCRIPTOR_NAME = "META-INF/ant-descriptor.xml";
     private final static String ROLE_DESCRIPTOR_NAME = "META-INF/ant-roles.xml";
+    private final static String SERVICE_DESCRIPTOR_NAME = "META-INF/ant-services.xml";
 
     private ClassLoader m_classLoader;
     private DefaultDeployer m_deployer;
-    private String[] m_descriptorUrls;
-    private Configuration[] m_descriptors;
+    private TypeDescriptor[] m_descriptors;
+    private ServiceDescriptor[] m_services;
+
+    // TODO - create and configure these in DefaultDeployer
+    private DescriptorBuilder m_roleBuilder = new RoleDescriptorBuilder();
+    private DescriptorBuilder m_typeBuilder = new TypeDescriptorBuilder();
+    private DescriptorBuilder m_serviceBuilder = new ServiceDescriptorBuilder();
 
     /** Map from role Class -> DefaultTypeFactory for that role. */
     private Map m_factories = new HashMap();
@@ -69,12 +65,13 @@ class Deployment
     /**
      * Load the descriptors.  Deploys all roles, then loads the descriptors
      * for, but does not deploy, all the types.
+     *
+     * @param jarUrl The URL for the typelib, used to locate the descriptors.
+     *               If null, the resources from the classloader are used.
      */
     public void loadDescriptors( final URL jarUrl )
         throws Exception
     {
-        final ArrayList descriptors = new ArrayList();
-
         // Create a SAX parser to assemble the descriptors into Configuration
         // objects
         final SAXParserFactory saxParserFactory = SAXParserFactory.newInstance();
@@ -86,45 +83,51 @@ class Deployment
         parser.setContentHandler( handler );
         parser.setErrorHandler( handler );
 
-        // Load the role descriptors, and deploy all roles
-        final List roleUrls = locateResources( ROLE_DESCRIPTOR_NAME, jarUrl );
-        for( Iterator iterator = roleUrls.iterator(); iterator.hasNext(); )
-        {
-            String url = (String)iterator.next();
-            try
-            {
-                parser.parse( url );
-            }
-            catch( FileNotFoundException e )
-            {
-                // Ignore - this happens when jarUrl != null and the Jar does
-                // not contain a role descriptor.
-                continue;
-            }
+        // Build the role descriptors
+        final ArrayList roleUrls = locateResources( ROLE_DESCRIPTOR_NAME, jarUrl );
+        final ArrayList roleDescriptors = buildDescriptors( roleUrls, m_roleBuilder, parser, handler );
 
-            handleRoleDescriptor( handler.getConfiguration(), url );
+        // Deploy the roles
+        // TODO - need to defer this
+        for( int i = 0; i < roleDescriptors.size(); i++ )
+        {
+            final RoleDescriptor descriptor = (RoleDescriptor)roleDescriptors.get( i );
+            deployRoles( descriptor );
         }
 
-        // Load type descriptors
-        final List typeUrls = locateResources( DESCRIPTOR_NAME, jarUrl );
-        for( Iterator iterator = typeUrls.iterator(); iterator.hasNext(); )
-        {
-            String url = (String)iterator.next();
-            try
-            {
-                parser.parse( url.toString() );
-            }
-            catch( FileNotFoundException e )
-            {
-                // Ignore - this happens when jarUrl != null and the Jar does
-                // not contain a type descriptor
-                continue;
-            }
+        // Build the type descriptors
+        final ArrayList typeUrls = locateResources( TYPE_DESCRIPTOR_NAME, jarUrl );
+        final ArrayList typeDescriptors = buildDescriptors( typeUrls, m_typeBuilder, parser, handler );
+        m_descriptors = (TypeDescriptor[])typeDescriptors.toArray( new TypeDescriptor[ typeDescriptors.size() ] );
 
-            descriptors.add( handler.getConfiguration() );
+        // Build the service descriptors
+        final ArrayList serviceUrls = locateResources( SERVICE_DESCRIPTOR_NAME, jarUrl );
+        final ArrayList serviceDescriptors = buildDescriptors( serviceUrls, m_serviceBuilder, parser, handler );
+        m_services = (ServiceDescriptor[])serviceDescriptors.toArray( new ServiceDescriptor[ serviceDescriptors.size() ] );
+    }
+
+    /**
+     * Returns the type factory for a role.
+     */
+    public DefaultTypeFactory getFactory( final Class roleType )
+    {
+        DefaultTypeFactory factory = (DefaultTypeFactory)m_factories.get( roleType );
+
+        if( null == factory )
+        {
+            factory = new DefaultTypeFactory( m_classLoader );
+            m_factories.put( roleType, factory );
         }
-        m_descriptorUrls = (String[])typeUrls.toArray( new String[ typeUrls.size() ] );
-        m_descriptors = (Configuration[])descriptors.toArray( new Configuration[ descriptors.size() ] );
+
+        return factory;
+    }
+
+    /**
+     * Returns the classloader for this deployment.
+     */
+    public ClassLoader getClassLoader()
+    {
+        return m_classLoader;
     }
 
     /**
@@ -135,8 +138,8 @@ class Deployment
     {
         for( int i = 0; i < m_descriptors.length; i++ )
         {
-            Configuration descriptor = m_descriptors[ i ];
-            deployFromDescriptor( descriptor, m_descriptorUrls[ i ] );
+            TypeDescriptor descriptor = m_descriptors[ i ];
+            deployTypes( descriptor );
         }
     }
 
@@ -148,19 +151,21 @@ class Deployment
     {
         try
         {
-            // Locate the entry for the type
+            // Locate the definition for the type
             for( int i = 0; i < m_descriptors.length; i++ )
             {
-                Configuration descriptor = m_descriptors[ i ];
-                final Configuration[] datatypes =
-                    descriptor.getChild( "types" ).getChildren( roleShorthand );
-                for( int j = 0; j < datatypes.length; j++ )
+                final TypeDescriptor descriptor = m_descriptors[ i ];
+                final TypeDefinition[] definitions = descriptor.getDefinitions();
+                for( int j = 0; j < definitions.length; j++ )
                 {
-                    Configuration datatype = datatypes[ j ];
-                    if( datatype.getAttribute( "name" ).equals( typeName ) )
+                    TypeDefinition definition = definitions[ j ];
+                    if( definition.getRole().equals( roleShorthand )
+                        && definition.getName().equals( typeName ) )
                     {
-                        final TypeDefinition typeDef = m_deployer.createTypeDefinition( datatype );
-                        m_deployer.handleType( this, typeDef );
+                        // Found the definition - deploy it.  Note that we
+                        // keep looking for matching types, and let the deployer
+                        // deal with duplicates
+                        m_deployer.deployType( this, definition );
                     }
                 }
             }
@@ -178,30 +183,63 @@ class Deployment
     public void deployType( final TypeDefinition typeDef )
         throws DeploymentException
     {
-        final String typeName = typeDef.getName();
-        final String roleShorthand = typeDef.getRole();
         try
         {
-            m_deployer.handleType( this, typeDef );
+            m_deployer.deployType( this, typeDef );
         }
         catch( Exception e )
         {
-            final String message = REZ.getString( "deploy-type.error", roleShorthand, typeName );
+            final String message = REZ.getString( "deploy-type.error", typeDef.getRole(), typeDef.getName() );
             throw new DeploymentException( message, e );
         }
     }
 
+    /**
+     * Builds descriptors.
+     */
+    private ArrayList buildDescriptors( final ArrayList urls,
+                                        final DescriptorBuilder builder,
+                                        final XMLReader parser,
+                                        final SAXConfigurationHandler handler )
+        throws Exception
+    {
+        final ArrayList descriptors = new ArrayList();
+        for( int i = 0; i < urls.size(); i++ )
+        {
+            final String url = (String)urls.get( i );
+
+            // Parse the file
+            parser.parse( url );
+            final TypelibDescriptor descriptor = builder.createDescriptor( handler.getConfiguration(), url );
+            descriptors.add( descriptor );
+        }
+
+        return descriptors;
+    }
+
     /**
      * Locates all resources of a particular name.
      */
-    private List locateResources( final String resource, final URL jarUrl )
+    private ArrayList locateResources( final String resource, final URL jarUrl )
         throws Exception
     {
         final ArrayList urls = new ArrayList();
         if( null != jarUrl )
         {
             final String systemID = "jar:" + jarUrl + "!/" + resource;
-            urls.add( systemID );
+            try
+            {
+                // Probe the resource
+                final URL url = new URL( systemID );
+                url.openStream().close();
+
+                // Add to the list
+                urls.add( systemID );
+            }
+            catch( FileNotFoundException e )
+            {
+                // Ignore
+            }
         }
         else
         {
@@ -216,77 +254,45 @@ class Deployment
     }
 
     /**
-     * Configure RoleManager based on contents of single descriptor.
-     *
-     * @param descriptor the descriptor
-     * @exception ConfigurationException if an error occurs
+     * Deploys the roles from a role descriptor.
      */
-    private void handleRoleDescriptor( final Configuration descriptor,
-                                       final String url )
-        throws ConfigurationException
+    private void deployRoles( final RoleDescriptor descriptor )
     {
-        final String message = REZ.getString( "url-deploy-roles.notice", url );
+        final String message = REZ.getString( "url-deploy-roles.notice", descriptor.getUrl() );
         getLogger().info( message );
 
-        final Configuration[] types = descriptor.getChildren( "role" );
-        for( int i = 0; i < types.length; i++ )
+        final RoleDefinition[] definitions = descriptor.getDefinitions();
+        for( int i = 0; i < definitions.length; i++ )
         {
-            final String name = types[ i ].getAttribute( "shorthand" );
-            final String role = types[ i ].getAttribute( "name" );
-            final RoleDefinition roleDef = new RoleDefinition( role, name );
-            m_deployer.handleRole( this, roleDef );
+            final RoleDefinition definition = definitions[ i ];
+            m_deployer.deployRole( this, definition );
         }
     }
 
     /**
      * Deploys all types from a typelib descriptor.
      */
-    private void deployFromDescriptor( final Configuration descriptor,
-                                       final String url )
+    private void deployTypes( final TypeDescriptor descriptor )
         throws DeploymentException
     {
         try
         {
-            final String message = REZ.getString( "url-deploy-types.notice", url );
+            final String message = REZ.getString( "url-deploy-types.notice", descriptor.getUrl() );
             getLogger().info( message );
 
             // Deploy all the types
-            final Configuration[] typeEntries = descriptor.getChild( "types" ).getChildren();
-            for( int i = 0; i < typeEntries.length; i++ )
+            final TypeDefinition[] definitions = descriptor.getDefinitions();
+            for( int i = 0; i < definitions.length; i++ )
             {
-                final Configuration typeEntry = typeEntries[ i ];
-                final TypeDefinition typeDef = m_deployer.createTypeDefinition( typeEntry );
-                m_deployer.handleType( this, typeDef );
+                final TypeDefinition definition = definitions[ i ];
+                m_deployer.deployType( this, definition );
             }
         }
         catch( final Exception e )
         {
-            final String message = REZ.getString( "deploy-lib.error", url );
+            final String message = REZ.getString( "deploy-types.error", descriptor.getUrl() );
             throw new DeploymentException( message, e );
         }
     }
 
-    /**
-     * Returns the type factory for a role.
-     */
-    public DefaultTypeFactory getFactory( final Class roleType )
-    {
-        DefaultTypeFactory factory = (DefaultTypeFactory)m_factories.get( roleType );
-
-        if( null == factory )
-        {
-            factory = new DefaultTypeFactory( m_classLoader );
-            m_factories.put( roleType, factory );
-        }
-
-        return factory;
-    }
-
-    /**
-     * Returns the classloader for this deployment.
-     */
-    public ClassLoader getClassLoader()
-    {
-        return m_classLoader;
-    }
 }

proposal/myrmidon/src/java/org/apache/myrmidon/components/deployer/DescriptorBuilder.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) The Apache Software Foundation. All rights reserved.
+ *
+ * This software is published under the terms of the Apache Software License
+ * version 1.1, a copy of which has been included  with this distribution in
+ * the LICENSE.txt file.
+ */
+package org.apache.myrmidon.components.deployer;
+
+import org.apache.avalon.framework.configuration.Configuration;
+import org.apache.myrmidon.interfaces.deployer.DeploymentException;
+
+/**
+ * Builds a descriptor.
+ *
+ * @author <a href="mailto:adammurdoch@apache.org">Adam Murdoch</a>
+ * @version $Revision$ $Date$
+ */
+interface DescriptorBuilder
+{
+    /**
+     * Builds a descriptor from a set of configuration.
+     */
+    TypelibDescriptor createDescriptor( Configuration config,
+                                        String descriptorUrl )
+        throws DeploymentException;
+}

proposal/myrmidon/src/java/org/apache/myrmidon/components/deployer/Resources.properties

@@ -4,9 +4,9 @@ register-role.notice=Registered role {0} with shorthand name {1}.
 url-deploy-types.notice=Registering types from "{0}".
 url-deploy-roles.notice=Registering roles from "{0}".
 
-deploy-from-classloader.error=Could not register types from ClassLoader {0}.
+deploy-from-classloader.error=Could not register types from ClassLoader.
 deploy-from-file.error=Could not register types from type library "{0}".
-deploy-lib.error=Could not register types from "{0}".
+deploy-types.error=Could not register types from "{0}".
 deploy-converter.error=Could not register converter that converts from {0} to {1}.
 deploy-type.error=Could not register type {0}/{1}.
 unknown-role4name.error=Unknown role "{0}".
@@ -17,6 +17,12 @@ typedef.no-name.error=Must specify name parameter.
 typedef.no-role.error=Must specify type parameter.
 converterdef.no-source.error=Must specify the source-type parameter.
 converterdef.no-destination.error=Must specify the destination-type parameter.
+role-descriptor-version.error=Role descriptor version {0} is incompatible with current version {1}.
+build-role-descriptor.error=Could not build role descriptor from "{0}".
+type-descriptor-version.error=Type library descriptor version {0} is incompatible with current version {1}.
+build-type-descriptor.error=Could not build type library descriptor from "{0}".
+service-descriptor-version.error=Service descriptor version {0} is incompatible with current version {1}.
+build-service-descriptor.error=Could not build service descriptor from "{0}".
 
 available-extensions.notice=The list of available extensions for type library includes; {0}
 required-extensions.notice=The list of required extensions for type library includes; {0}

proposal/myrmidon/src/java/org/apache/myrmidon/components/deployer/RoleDescriptor.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) The Apache Software Foundation. All rights reserved.
+ *
+ * This software is published under the terms of the Apache Software License
+ * version 1.1, a copy of which has been included  with this distribution in
+ * the LICENSE.txt file.
+ */
+package org.apache.myrmidon.components.deployer;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A typelib role descriptor, which defines a set of roles.
+ *
+ * @author <a href="mailto:adammurdoch@apache.org">Adam Murdoch</a>
+ * @version $Revision$ $Date$
+ */
+class RoleDescriptor
+    extends TypelibDescriptor
+{
+    private final List m_definitions = new ArrayList();
+
+    public RoleDescriptor( final String url )
+    {
+        super( url );
+    }
+
+    /**
+     * Returns the role definitions in the descriptor.
+     */
+    public RoleDefinition[] getDefinitions()
+    {
+        return (RoleDefinition[])m_definitions.toArray( new RoleDefinition[ m_definitions.size() ] );
+    }
+
+    /**
+     * Adds a role definition to the descriptor.
+     */
+    public void addDefinition( final RoleDefinition def )
+    {
+        m_definitions.add( def );
+    }
+}

proposal/myrmidon/src/java/org/apache/myrmidon/components/deployer/RoleDescriptorBuilder.java

@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) The Apache Software Foundation. All rights reserved.
+ *
+ * This software is published under the terms of the Apache Software License
+ * version 1.1, a copy of which has been included  with this distribution in
+ * the LICENSE.txt file.
+ */
+package org.apache.myrmidon.components.deployer;
+
+import org.apache.avalon.excalibur.i18n.ResourceManager;
+import org.apache.avalon.excalibur.i18n.Resources;
+import org.apache.avalon.framework.Version;
+import org.apache.avalon.framework.configuration.Configuration;
+import org.apache.myrmidon.interfaces.deployer.DeploymentException;
+
+/**
+ * Builds typelib role descriptors.
+ *
+ * @author <a href="mailto:adammurdoch@apache.org">Adam Murdoch</a>
+ * @version $Revision$ $Date$
+ */
+class RoleDescriptorBuilder
+    implements DescriptorBuilder
+{
+    private final static Resources REZ =
+        ResourceManager.getPackageResources( RoleDescriptorBuilder.class );
+
+    private final static Version ROLE_DESCRIPTOR_VERSION = new Version( 1, 0, 0 );
+
+    /**
+     * Builds a descriptor from a set of configuration.
+     */
+    public TypelibDescriptor createDescriptor( final Configuration config,
+                                               final String url )
+        throws DeploymentException
+    {
+        try
+        {
+            // Check version
+            final String versionString = config.getAttribute( "version" );
+            final Version version = Version.getVersion( versionString );
+            if( ! ROLE_DESCRIPTOR_VERSION.complies( version ) )
+            {
+                final String message = REZ.getString( "role-descriptor-version.error", version, ROLE_DESCRIPTOR_VERSION );
+                throw new DeploymentException( message );
+            }
+
+            // Assemble the descriptor
+            final RoleDescriptor descriptor = new RoleDescriptor( url );
+
+            // Extract each of the role elements
+            final Configuration[] types = config.getChildren( "role" );
+            for( int i = 0; i < types.length; i++ )
+            {
+                final String name = types[ i ].getAttribute( "shorthand" );
+                final String role = types[ i ].getAttribute( "name" );
+                final RoleDefinition roleDef = new RoleDefinition( role, name );
+                descriptor.addDefinition( roleDef );
+            }
+
+            return descriptor;
+        }
+        catch( Exception e )
+        {
+            final String message = REZ.getString( "build-role-descriptor.error", url );
+            throw new DeploymentException( message, e );
+        }
+    }
+}

proposal/myrmidon/src/java/org/apache/myrmidon/components/deployer/ServiceDefinition.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) The Apache Software Foundation. All rights reserved.
+ *
+ * This software is published under the terms of the Apache Software License
+ * version 1.1, a copy of which has been included  with this distribution in
+ * the LICENSE.txt file.
+ */
+package org.apache.myrmidon.components.deployer;
+
+import org.apache.avalon.framework.configuration.Configuration;
+
+/**
+ * A service definition.
+ *
+ * @author <a href="mailto:adammurdoch@apache.org">Adam Murdoch</a>
+ * @version $Revision$ $Date$
+ */
+class ServiceDefinition
+{
+    private final String m_roleShorthand;
+    private final String m_factoryClass;
+    private final Configuration m_config;
+
+    public ServiceDefinition( final String roleShorthand,
+                              final String factoryClass,
+                              final Configuration config )
+    {
+        m_roleShorthand = roleShorthand;
+        m_factoryClass = factoryClass;
+        m_config = config;
+    }
+
+    /**
+     * Returns the role that the service implements.
+     */
+    public String getRoleShorthand()
+    {
+        return m_roleShorthand;
+    }
+
+    /**
+     * Returns the name of the factory class for creating the service.
+     */
+    public String getFactoryClass()
+    {
+        return m_factoryClass;
+    }
+
+    /**
+     * Returns the service configuration.
+     */
+    public Configuration getConfig()
+    {
+        return m_config;
+    }
+}

proposal/myrmidon/src/java/org/apache/myrmidon/components/deployer/ServiceDescriptor.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) The Apache Software Foundation. All rights reserved.
+ *
+ * This software is published under the terms of the Apache Software License
+ * version 1.1, a copy of which has been included  with this distribution in
+ * the LICENSE.txt file.
+ */
+package org.apache.myrmidon.components.deployer;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A typelib service descriptor, which defines a set of services.
+ *
+ * @author <a href="mailto:adammurdoch@apache.org">Adam Murdoch</a>
+ * @version $Revision$ $Date$
+ */
+class ServiceDescriptor
+    extends TypelibDescriptor
+{
+    private final List m_services = new ArrayList();
+
+    public ServiceDescriptor( final String url )
+    {
+        super( url );
+    }
+
+    public ServiceDefinition[] getDefinitions()
+    {
+        return (ServiceDefinition[])m_services.toArray( new ServiceDefinition[ m_services.size() ] );
+    }
+
+    public void addDefinition( final ServiceDefinition definition )
+    {
+        m_services.add( definition );
+    }
+}

proposal/myrmidon/src/java/org/apache/myrmidon/components/deployer/ServiceDescriptorBuilder.java

@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) The Apache Software Foundation. All rights reserved.
+ *
+ * This software is published under the terms of the Apache Software License
+ * version 1.1, a copy of which has been included  with this distribution in
+ * the LICENSE.txt file.
+ */
+package org.apache.myrmidon.components.deployer;
+
+import org.apache.avalon.excalibur.i18n.ResourceManager;
+import org.apache.avalon.excalibur.i18n.Resources;
+import org.apache.avalon.framework.Version;
+import org.apache.avalon.framework.configuration.Configuration;
+import org.apache.myrmidon.interfaces.deployer.DeploymentException;
+
+/**
+ * Builds typelib service descriptors.
+ *
+ * @author <a href="mailto:adammurdoch@apache.org">Adam Murdoch</a>
+ * @version $Revision$ $Date$
+ */
+class ServiceDescriptorBuilder
+    implements DescriptorBuilder
+{
+    private final static Resources REZ =
+        ResourceManager.getPackageResources( ServiceDescriptorBuilder.class );
+
+    private final static Version SERVICE_DESCRIPTOR_VERSION = new Version( 1, 0, 0 );
+
+    /**
+     * Builds a descriptor from a set of configuration.
+     */
+    public TypelibDescriptor createDescriptor( final Configuration config,
+                                               final String url )
+        throws DeploymentException
+    {
+        try
+        {
+            // Check version
+            final String versionString = config.getAttribute( "version" );
+            final Version version = Version.getVersion( versionString );
+            if( ! SERVICE_DESCRIPTOR_VERSION.complies( version ) )
+            {
+                final String message = REZ.getString( "service-descriptor-version.error", version, SERVICE_DESCRIPTOR_VERSION );
+                throw new DeploymentException( message );
+            }
+
+            // TODO - populate the descriptor
+
+            return new ServiceDescriptor( url );
+        }
+        catch( Exception e )
+        {
+            final String message = REZ.getString( "build-service-descriptor.error", url );
+            throw new DeploymentException( message, e );
+        }
+    }
+}

proposal/myrmidon/src/java/org/apache/myrmidon/components/deployer/TypeDescriptor.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) The Apache Software Foundation. All rights reserved.
+ *
+ * This software is published under the terms of the Apache Software License
+ * version 1.1, a copy of which has been included  with this distribution in
+ * the LICENSE.txt file.
+ */
+package org.apache.myrmidon.components.deployer;
+
+import java.util.ArrayList;
+import java.util.List;
+import org.apache.myrmidon.interfaces.deployer.TypeDefinition;
+
+/**
+ * A typelib type descriptor, which defines a set of types.
+ *
+ * @author <a href="mailto:adammurdoch@apache.org">Adam Murdoch</a>
+ * @version $Revision$ $Date$
+ */
+class TypeDescriptor
+    extends TypelibDescriptor
+{
+    private final List m_definitions = new ArrayList();
+
+    public TypeDescriptor( final String url )
+    {
+        super( url );
+    }
+
+    public TypeDefinition[] getDefinitions()
+    {
+        return (TypeDefinition[])m_definitions.toArray( new TypeDefinition[ m_definitions.size() ] );
+    }
+
+    public void addDefinition( final TypeDefinition def )
+    {
+        m_definitions.add( def );
+    }
+}

proposal/myrmidon/src/java/org/apache/myrmidon/components/deployer/TypeDescriptorBuilder.java

@@ -0,0 +1,95 @@
+/*
+ * Copyright (C) The Apache Software Foundation. All rights reserved.
+ *
+ * This software is published under the terms of the Apache Software License
+ * version 1.1, a copy of which has been included  with this distribution in
+ * the LICENSE.txt file.
+ */
+package org.apache.myrmidon.components.deployer;
+
+import org.apache.avalon.excalibur.i18n.ResourceManager;
+import org.apache.avalon.excalibur.i18n.Resources;
+import org.apache.avalon.framework.Version;
+import org.apache.avalon.framework.configuration.Configuration;
+import org.apache.avalon.framework.configuration.ConfigurationException;
+import org.apache.myrmidon.interfaces.deployer.ConverterDefinition;
+import org.apache.myrmidon.interfaces.deployer.DeploymentException;
+import org.apache.myrmidon.interfaces.deployer.TypeDefinition;
+
+/**
+ * Builds typelib type descriptors.
+ *
+ * @author <a href="mailto:adammurdoch@apache.org">Adam Murdoch</a>
+ * @version $Revision$ $Date$
+ */
+class TypeDescriptorBuilder
+    implements DescriptorBuilder
+{
+    private final static Resources REZ =
+        ResourceManager.getPackageResources( TypeDescriptorBuilder.class );
+
+    private final static Version TYPE_DESCRIPTOR_VERSION = new Version( 1, 0, 0 );
+
+    /**
+     * Builds a descriptor from a set of configuration.
+     */
+    public TypelibDescriptor createDescriptor( final Configuration config,
+                                               final String url )
+        throws DeploymentException
+    {
+        try
+        {
+            // Check version
+            final String versionString = config.getAttribute( "version" );
+            final Version version = Version.getVersion( versionString );
+            if( ! TYPE_DESCRIPTOR_VERSION.complies( version ) )
+            {
+                final String message = REZ.getString( "type-descriptor-version.error", version, TYPE_DESCRIPTOR_VERSION );
+                throw new DeploymentException( message );
+            }
+
+            // Assemble the descriptor
+            final TypeDescriptor descriptor = new TypeDescriptor( url );
+
+            // Extract each of the types elements
+            final Configuration[] typeEntries = config.getChild( "types" ).getChildren();
+            for( int i = 0; i < typeEntries.length; i++ )
+            {
+                final Configuration typeEntry = typeEntries[ i ];
+                final TypeDefinition typeDef = createTypeDefinition( typeEntry );
+                descriptor.addDefinition( typeDef );
+            }
+
+            return descriptor;
+        }
+        catch( Exception e )
+        {
+            final String message = REZ.getString( "build-type-descriptor.error", url );
+            throw new DeploymentException( message, e );
+        }
+    }
+
+    /**
+     * Creates a type definition.
+     */
+    public TypeDefinition createTypeDefinition( final Configuration configuration )
+        throws ConfigurationException
+    {
+        final String roleShorthand = configuration.getName();
+        if( roleShorthand.equals( "converter" ) )
+        {
+            // A converter definition
+            final String className = configuration.getAttribute( "classname" );
+            final String source = configuration.getAttribute( "source" );
+            final String destination = configuration.getAttribute( "destination" );
+            return new ConverterDefinition( className, source, destination );
+        }
+        else
+        {
+            // A type definition
+            final String typeName = configuration.getAttribute( "name" );
+            final String className = configuration.getAttribute( "classname" );
+            return new TypeDefinition( typeName, roleShorthand, className );
+        }
+    }
+}

proposal/myrmidon/src/java/org/apache/myrmidon/components/deployer/TypelibDescriptor.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) The Apache Software Foundation. All rights reserved.
+ *
+ * This software is published under the terms of the Apache Software License
+ * version 1.1, a copy of which has been included  with this distribution in
+ * the LICENSE.txt file.
+ */
+package org.apache.myrmidon.components.deployer;
+
+/**
+ * A descriptor from a typelib.
+ *
+ * @author <a href="mailto:adammurdoch@apache.org">Adam Murdoch</a>
+ * @version $Revision$ $Date$
+ */
+class TypelibDescriptor
+{
+    private final String m_url;
+
+    public TypelibDescriptor( final String url )
+    {
+        m_url = url;
+    }
+
+    /**
+     * Returns the descriptor URL.
+     */
+    public String getUrl()
+    {
+        return m_url;
+    }
+}