Started the type registry impl.

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@269075 13f79535-47bb-0310-9956-ffa450edef68

proposal/myrmidon/src/java/org/apache/myrmidon/components/type/ComponentFactory.java

@@ -0,0 +1,30 @@
+/*
+ * 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 file.
+ */
+package org.apache.myrmidon.components.type;
+
+import org.apache.avalon.framework.component.Component;
+import org.apache.avalon.framework.component.ComponentException;
+
+/**
+ * Create a component based on role and hint.
+ *
+ * @author <a href="mailto:donaldp@apache.org">Peter Donald</a>
+ * @version CVS $Revision$ $Date$
+ */
+public interface ComponentFactory
+{
+    /**
+     * Create a Component with appropriate name.
+     *
+     * @param name the name
+     * @return the created component
+     * @exception ComponentException if an error occurs
+     */
+    Component create( String name )
+        throws ComponentException;
+}

proposal/myrmidon/src/java/org/apache/myrmidon/components/type/DefaultComponentFactory.java

@@ -0,0 +1,104 @@
+/*
+ * 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 file.
+ */
+package org.apache.myrmidon.components.type;
+
+import java.net.URL;
+import java.util.HashMap;
+import java.net.URLClassLoader;
+import org.apache.avalon.framework.component.Component;
+import org.apache.avalon.framework.component.ComponentException;
+
+/**
+ * Create a component based on name.
+ *
+ * @author <a href="mailto:donaldp@apache.org">Peter Donald</a>
+ * @version CVS $Revision$ $Date$
+ */
+public class DefaultComponentFactory
+    implements ComponentFactory
+{
+    ///A Map of shortnames to classnames
+    private final HashMap        m_classNames = new HashMap();
+
+    ///A list of URLs from which classLoader is constructed
+    private final URL[]          m_urls;
+
+    ///The parent classLoader (if any)
+    private final ClassLoader    m_parent;
+
+    ///The parent classLoader (if any)
+    private ClassLoader          m_classLoader;
+
+    public DefaultComponentFactory( final URL[] urls )
+    {
+        this( urls, null );
+    }
+
+    public DefaultComponentFactory( final URL[] urls, final ClassLoader parent )
+    {
+        m_urls = urls;
+        m_parent = parent;
+    }
+
+    public DefaultComponentFactory( final ClassLoader classLoader )
+    {
+        this( null, null );
+        m_classLoader = classLoader;
+    }
+
+    public void addNameClassMapping( final String name, final String className )
+    {
+        m_classNames.put( name, className );
+    }
+
+    /**
+     * Create a Component with appropriate name.
+     *
+     * @param name the name
+     * @return the created component
+     * @exception ComponentException if an error occurs
+     */
+    public Component create( final String name )
+        throws ComponentException
+    {
+        final String className = getClassName( name );
+
+        try
+        {
+            return (Component)getClassLoader().loadClass( className ).newInstance();
+        }
+        catch( final Exception e )
+        {
+            throw new ComponentException( "Unable to instantiate '" + name + "'", e );
+        }
+    }
+
+    private String getClassName( final String name )
+        throws ComponentException
+    {
+        final String className = (String)m_classNames.get( name );
+
+        if( null == className )
+        {
+            throw new ComponentException( "Malconfigured factory, no clasname for '" + 
+                                          name + "'" );
+        }
+        
+        return className;
+    }
+
+    private ClassLoader getClassLoader()
+    {
+        if( null == m_classLoader )
+        {
+            m_classLoader = new URLClassLoader( m_urls, m_parent );
+        }
+        
+        return m_classLoader;
+    }
+}

proposal/myrmidon/src/java/org/apache/myrmidon/components/type/RoleManager.java

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+/*
+ * 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 file.
+ */
+package org.apache.myrmidon.components.type;
+
+import java.util.HashMap;
+
+/**
+ * Interface to manage roles and mapping to shorthand names.
+ *
+ * @author <a href="mailto:bloritsch@apache.org">Berin Loritsch</a>
+ * @author <a href="mailto:ricardo@apache,org">Ricardo Rocha</a>
+ * @author <a href="mailto:giacomo@apache,org">Giacomo Pati</a>
+ * @author <a href="mailto:donaldp@apache.org">Peter Donald</a>
+ * @version CVS $Revision$ $Date$
+ */
+public class RoleManager
+{
+    /** Parent <code>RoleManager</code> for nested resolution */
+    private final RoleManager  m_parent;
+
+    /** Map for shorthand to role mapping */
+    private final HashMap      m_shorthands = new HashMap();
+
+    /**
+     *  constructor--this RoleManager has no parent.
+     */
+    public RoleManager()
+    {
+        this( null );
+    }
+
+    /**
+     * Alternate constructor--this RoleManager has the specified
+     * parent.
+     *
+     * @param parent The parent <code>RoleManager</code>.
+     */
+    public RoleManager( final RoleManager parent )
+    {
+        m_parent = parent;
+    }
+
+    /**
+     * Find Role name based on shorthand name.
+     *
+     * @param shorthandName the shorthand name
+     * @return the role
+     */
+    public String getRoleForName( final String shorthandName )
+    {
+        final String role = (String)m_shorthands.get( shorthandName );
+
+        if( null == role && null != m_parent )
+        {
+            return m_parent.getRoleForName( shorthandName );
+        }
+
+        return role;
+    }
+
+    /**
+     * Add a mapping between shorthand name and role
+     *
+     * @param shorthandName the shorthand name
+     * @param role the role
+     * @exception IllegalArgumentException if an name is already mapped to a different role
+     */
+    public void addNameRoleMapping( final String shorthandName, final String role )
+        throws IllegalArgumentException
+    {
+        final String oldRole = (String)m_shorthands.get( shorthandName );
+
+        if( null != oldRole && oldRole.equals( role ) )
+        {
+            throw new IllegalArgumentException( "Name already mapped to another role (" +
+                                                oldRole + ")" );
+        }
+
+        m_shorthands.put( shorthandName, role );
+    }
+}

proposal/myrmidon/src/java/org/apache/myrmidon/components/type/TypedComponentSelector.java

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+/*
+ * 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 file.
+ */
+package org.apache.myrmidon.components.type;
+
+import java.util.HashMap;
+import org.apache.avalon.framework.component.Component;
+import org.apache.avalon.framework.component.ComponentSelector;
+import org.apache.avalon.framework.component.ComponentException;
+
+/**
+ * This is a ComponentSelector implementation that acts as factory
+ * for objects and checks type on creation.
+ *
+ * @author <a href="mailto:donaldp@apache.org">Peter Donald</a>
+ */
+public class TypedComponentSelector
+    implements ComponentSelector
+{
+    private final HashMap  m_factorys = new HashMap();
+
+    private final Class    m_type;
+
+    public TypedComponentSelector( final Class type )
+    {
+        m_type = type;
+    }
+
+    /**
+     * Select the desired component.  
+     * This creates component and checks if type appropriate.
+     *
+     * @param hint the hint to retrieve Component 
+     * @return the Component
+     * @exception ComponentException if an error occurs
+     */
+    public Component select( Object hint )
+        throws ComponentException
+    {
+        if( !(hint instanceof String) )
+        {
+            throw new ComponentException( "Invalid hint, expected a string not a " + 
+                                          hint.getClass().getName() );
+        }
+        
+        final Component component = createComponent( (String)hint );
+
+        if( null != component )
+        {
+            if( m_type.isInstance( component ) )
+            {
+                throw new ComponentException( "Implementation of " + hint + " is not of " +
+                                              "correct type (" + m_type.getClass().getName() + ")" );
+            }
+
+            return component;
+        }
+        else
+        {
+            throw new ComponentException( "Unable to provide implementation for " + hint );
+        }
+    }
+
+    /**
+     * Release component.
+     *
+     * @param component the component
+     */
+    public void release( final Component component )
+    {
+    }
+
+    /**
+     * Populate the ComponentSelector.
+     */
+    public void put( final String name, final ComponentFactory factory )
+    {
+        m_factorys.put( name, factory );
+    }
+
+    /**
+     * Helper method for subclasses to retrieve component map.
+     *
+     * @return the component map
+     */
+    private Component createComponent( final String name )
+        throws ComponentException
+    {
+        final ComponentFactory factory = (ComponentFactory)m_factorys.get( name );
+        
+        if( null == factory ) return null;
+        else
+        {
+            return factory.create( name );
+        }
+    }
+}