DPML Notify

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

Author: davidoff
Date: 2007-09-18 13:59:40 +0200 (Tue, 18 Sep 2007)
New Revision: 2044

Added:
   trunk/main/transit/core/src/main/dpml/transit/configuration/
   
trunk/main/transit/core/src/main/dpml/transit/configuration/ConfigurationURLConnection.java
   trunk/main/transit/core/src/main/dpml/transit/configuration/Handler.java
   
trunk/main/transit/core/src/main/dpml/transit/configuration/package-info.java
Log:
Add configuration hajndler package.

Added: 
trunk/main/transit/core/src/main/dpml/transit/configuration/ConfigurationURLConnection.java
===================================================================
--- 
trunk/main/transit/core/src/main/dpml/transit/configuration/ConfigurationURLConnection.java
 2007-09-18 05:21:36 UTC (rev 2043)
+++ 
trunk/main/transit/core/src/main/dpml/transit/configuration/ConfigurationURLConnection.java
 2007-09-18 11:59:40 UTC (rev 2044)
@@ -0,0 +1,273 @@
+/*
+ * Copyright 2007 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 dpml.transit.configuration;
+
+import dpml.transit.TransitContext;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.FileInputStream;
+import java.io.OutputStream;
+import java.io.FileOutputStream;
+import java.io.File;
+import java.net.URL;
+import java.net.URLConnection;
+import java.security.AccessController;
+import java.security.PrivilegedExceptionAction;
+import java.security.PrivilegedActionException;
+import java.security.PrivilegedAction;
+
+import net.dpml.transit.Transit;
+import net.dpml.transit.Artifact;
+import net.dpml.transit.ArtifactException;
+import net.dpml.transit.ContentHandler;
+
+/**
+ * The local URL protocol connection implementation.
+ * @author <a href="@PUBLISHER-URL@">@PUBLISHER-NAME@</a>
+ * @version @PROJECT-VERSION@
+ */
+public class ConfigurationURLConnection extends URLConnection
+{
+   /**
+    * Transit context.
+    */
+    private final TransitContext m_context;
+
+    private boolean m_connected;
+
+    private File m_target;
+
+    /**
+     * Creation of a new local handler.
+     * @param url the url to establish a connection with
+     * @exception NullPointerException if the url argument is null
+     */
+    ConfigurationURLConnection( URL url, TransitContext context )
+        throws NullPointerException
+    {
+        super( url );
+
+        m_context = context;
+        m_connected = false;
+    }
+
+   /**
+    * Establish a connection.
+    *
+    * @exception IOException is an error occurs while attempting to establish
+    *  the connection.
+    */
+    public void connect()
+        throws IOException
+    {
+        if( m_connected )
+        {
+            return;
+        }
+
+        m_connected = true;
+        
+        try
+        {
+            AccessController.doPrivileged( 
+              new PrivilegedExceptionAction<Object>()
+              {
+                public Object run()
+                    throws IOException
+                {
+                    String spec = url.toExternalForm();
+                    try
+                    {
+                        Artifact artifact = Artifact.createArtifact( spec );
+                        String groupSpec = artifact.getGroup();
+                        String artifactName = artifact.getName();
+                        String typeSpec = artifact.getType();
+                        String versionSpec = artifact.getVersion();
+                        File config = Transit.CONFIG;
+                        File group = new File( config, groupSpec );
+                        File type = new File( group, typeSpec + "s" );
+                        if( null == versionSpec )
+                        {
+                            final String filename = artifactName + "." + 
typeSpec;
+                            m_target = new File( type, filename );
+                        }
+                        else
+                        {
+                            final String filename = artifactName + "-" + 
versionSpec + "." + typeSpec;
+                            m_target = new File( type, filename );
+                        }
+                    }
+                    catch( Throwable e )
+                    {
+                        String message = e.getMessage();
+                        IOException exception = new IOException( message );
+                        exception.initCause( e.getCause() );
+                        throw exception;
+                    }
+                    return null; // nothing to return
+                }
+              }
+            );
+        } 
+        catch( PrivilegedActionException e )
+        {
+            throw (IOException) e.getException();
+        } 
+    }
+
+   /**
+    * Return an input stream to the resource.
+    * @return the input stream
+    * @exception IOException is an error occurs
+    */
+    public InputStream getInputStream()
+        throws IOException
+    {
+        connect();
+        if( m_target == null )
+        {
+            return null;
+        }
+        else
+        {
+            return new FileInputStream( m_target );
+        }
+    }
+
+   /**
+    * Return an output stream to the resource.
+    * @return the output stream
+    * @exception IOException if any I/O problems occur.
+    */
+    public OutputStream getOutputStream()
+        throws IOException
+    {
+        return null;
+    }
+
+   /**
+    * Return the content for this local resource.
+    * @param classes a sequence of classes against which the
+    *   implementation will attempt to establish a known match
+    * @return the content object (possibly null)
+    * @exception IOException is an error occurs
+    */
+    public Object getContent( final Class[] classes )
+        throws IOException
+    {
+        connect();
+        Object result = AccessController.doPrivileged( 
+          new PrivilegedAction<Object>()
+          {
+            public Object run()
+            {
+                for( int i=0; i < classes.length; i++ )
+                {
+                    Class c = classes[i];
+                    if( c.equals( File.class ) )
+                    {
+                        return m_target;
+                    }
+                }
+                return null;
+            }
+          }
+        );
+
+        if( null != result )
+        {
+            return result;
+        }
+        else
+        {
+            if( null != m_target )
+            {
+                String spec = url.toExternalForm();
+                try
+                {
+                    Artifact artifact = Artifact.createArtifact( spec );
+                    String type = artifact.getType();
+                    ContentHandler handler = m_context.getContentHandler( 
type );
+                    if( null != handler )
+                    {
+                        URLConnection connection = 
m_target.toURI().toURL().openConnection();
+                        return handler.getContent( connection, classes );
+                    }
+                    else
+                    {
+                        URLConnection connection = 
m_target.toURI().toURL().openConnection();
+                        return connection.getContent( classes );
+                    }
+                }
+                catch( Exception e )
+                {
+                    final String error = 
+                      "Internal error in config url connection handler.";
+                    throw new ArtifactException( error, e );
+                }
+            }
+            else
+            {
+                return super.getContent( classes );
+            }
+        }
+    }
+    
+   /**
+    * Return the link content by delegating to the underlying artifact.
+    * @return the artifact content
+    * @exception IOException if an IO error occurs
+    */
+    public Object getContent()
+        throws IOException
+    {
+        connect();
+        if( null != m_target )
+        {
+            String spec = url.toExternalForm();
+            try
+            {
+                Artifact artifact = Artifact.createArtifact( spec );
+                String type = artifact.getType();
+                ContentHandler handler = m_context.getContentHandler( type );
+                if( null != handler )
+                {
+                    URLConnection connection = 
m_target.toURI().toURL().openConnection();
+                    return handler.getContent( connection );
+                }
+                else
+                {
+                    URLConnection connection = 
m_target.toURI().toURL().openConnection();
+                    return connection.getContent();
+                }
+            }
+            catch( Exception e )
+            {
+                final String error = 
+                  "Internal error in config url connection handler.";
+                throw new ArtifactException( error, e );
+            }
+        }
+        else
+        {
+            return super.getContent();
+        }
+    }
+}

Added: 
trunk/main/transit/core/src/main/dpml/transit/configuration/Handler.java
===================================================================
--- trunk/main/transit/core/src/main/dpml/transit/configuration/Handler.java  
  2007-09-18 05:21:36 UTC (rev 2043)
+++ trunk/main/transit/core/src/main/dpml/transit/configuration/Handler.java  
  2007-09-18 11:59:40 UTC (rev 2044)
@@ -0,0 +1,60 @@
+/*
+ * Copyright 2007 Stephen 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 dpml.transit.configuration;
+
+import dpml.transit.TransitContext;
+
+import java.io.IOException;
+import java.net.URL;
+import java.net.URLConnection;
+import java.net.URLStreamHandler;
+
+/** 
+ * The <code>configuration</code> protocol references a read-only 
configuration resource 
+ * under ${dpml.condfig}. Configuration resources are located using the 
artifact 
+ * protocol uri structure with a direct mapping to 
${dpml.config}/[group]/[type]s/[name].[type].
+ * @author <a href="@PUBLISHER-URL@">@PUBLISHER-NAME@</a>
+ * @version @PROJECT-VERSION@
+ */
+public class Handler extends URLStreamHandler
+{
+   /**
+    * Creation of a new configuration protocol handler.
+    */
+    public Handler()
+    {
+    }
+
+    // 
------------------------------------------------------------------------
+    // implementation
+    // 
------------------------------------------------------------------------
+
+    /**
+     * Opens a connection to the specified URL.
+     *
+     * @param url A URL to open a connection to.
+     * @return The established connection.
+     * @throws IOException If a connection failure occurs.
+     */
+    protected URLConnection openConnection( final URL url )
+        throws IOException
+    {
+        TransitContext context = TransitContext.getInstance();
+        return new ConfigurationURLConnection( url, context );
+    }
+}

Added: 
trunk/main/transit/core/src/main/dpml/transit/configuration/package-info.java
===================================================================
--- 
trunk/main/transit/core/src/main/dpml/transit/configuration/package-info.java 
      2007-09-18 05:21:36 UTC (rev 2043)
+++ 
trunk/main/transit/core/src/main/dpml/transit/configuration/package-info.java 
      2007-09-18 11:59:40 UTC (rev 2044)
@@ -0,0 +1,25 @@
+/*
+ * Copyright 2007 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.
+ */
+
+/**
+ * Transit <tt>configuration</tt> protocol handler.
+ *
+ * @author <a href="@PUBLISHER-URL@">@PUBLISHER-NAME@</a>
+ * @version @PROJECT-VERSION@
+ */
+package dpml.transit.configuration;