Abstract task to define types.

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@269120 13f79535-47bb-0310-9956-ffa450edef68

proposal/myrmidon/src/java/org/apache/myrmidon/framework/AbstractTypeDef.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.framework;
+
+import java.io.File;
+import java.net.URL;
+import java.net.URLClassLoader;
+import org.apache.avalon.framework.component.ComponentException;
+import org.apache.avalon.framework.component.ComponentManager;
+import org.apache.avalon.framework.component.Composable;
+import org.apache.myrmidon.api.AbstractTask;
+import org.apache.myrmidon.api.TaskException;
+import org.apache.myrmidon.components.deployer.RoleManager;
+import org.apache.myrmidon.components.type.DefaultTypeFactory;
+import org.apache.myrmidon.components.type.TypeException;
+import org.apache.myrmidon.components.type.TypeManager;
+
+/**
+ * Abstract task to extend to define a type.
+ *
+ * TODO: Make this support classpath sub-element in future
+ *
+ * @author <a href="mailto:donaldp@apache.org">Peter Donald</a>
+ */
+public abstract class AbstractTypeDef
+    extends AbstractTask
+    implements Composable
+{
+    private String              m_lib;
+    private String              m_name;
+    private String              m_className;
+    private TypeManager         m_typeManager;
+    private RoleManager         m_roleManager;
+
+    public void compose( final ComponentManager componentManager )
+        throws ComponentException
+    {
+        m_typeManager = (TypeManager)componentManager.lookup( TypeManager.ROLE );
+        m_roleManager = (RoleManager)componentManager.lookup( RoleManager.ROLE );
+    }
+
+    public void setLib( final String lib )
+    {
+        //In the future this would be replaced by ClassPath sub-element
+        m_lib = lib;
+    }
+
+    public void setName( final String name )
+    {
+        m_name = name;
+    }
+
+    public void setClassname( final String className )
+    {
+        m_className = className;
+    }
+
+    public void execute()
+        throws TaskException
+    {
+        if( null == m_name )
+        {
+            throw new TaskException( "Must specify name parameter" );
+        }
+        else if( null == m_className )
+        {
+            throw new TaskException( "Must specify classname parameter" );
+        }
+
+        final String typeName = getTypeName();
+        final String role = m_roleManager.getRoleForName( typeName );
+
+        final ClassLoader classLoader = createClassLoader();
+        final DefaultTypeFactory factory = new DefaultTypeFactory( classLoader );
+        factory.addNameClassMapping( m_name, m_className );
+
+        try { m_typeManager.registerType( role, m_name, factory ); }
+        catch( final TypeException te )
+        {
+            throw new TaskException( "Failed to register type", te );
+        }
+    }
+
+    protected ClassLoader createClassLoader()
+        throws TaskException
+    {
+        //TODO: Make this support classpath sub-element in future
+
+        try
+        {
+            final File file = getContext().resolveFile( m_lib );
+            final URL url = file.getCanonicalFile().toURL();
+            final ClassLoader classLoader =
+                Thread.currentThread().getContextClassLoader();
+
+            return new URLClassLoader( new URL[] { url }, classLoader );
+        }
+        catch( final Exception e )
+        {
+            throw new TaskException( "Failed to build classLoader due to: " + e, e );
+        }
+    }
+
+    protected final TypeManager getTypeManager()
+    {
+        return m_typeManager;
+    }
+
+    protected abstract String getTypeName();
+}