DefaultModelProcessor.java
/*
* Copyright (C) Christian Schulte <cs@schulte.it>, 2005-206
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* o Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* o Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $JOMC: DefaultModelProcessor.java 5043 2015-05-27 07:03:39Z schulte $
*
*/
package org.jomc.model.modlet;
import java.net.URISyntaxException;
import java.net.URL;
import java.text.MessageFormat;
import java.util.Enumeration;
import java.util.LinkedList;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.ResourceBundle;
import java.util.logging.Level;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBElement;
import javax.xml.bind.JAXBException;
import javax.xml.bind.util.JAXBResult;
import javax.xml.bind.util.JAXBSource;
import javax.xml.transform.ErrorListener;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.stream.StreamSource;
import org.jomc.modlet.Model;
import org.jomc.modlet.ModelContext;
import org.jomc.modlet.ModelException;
import org.jomc.modlet.ModelProcessor;
/**
* Default object management and configuration {@code ModelProcessor} implementation.
*
* @author <a href="mailto:cs@schulte.it">Christian Schulte</a>
* @version $JOMC: DefaultModelProcessor.java 5043 2015-05-27 07:03:39Z schulte $
* @see ModelContext#processModel(org.jomc.modlet.Model)
*/
public class DefaultModelProcessor implements ModelProcessor
{
/**
* Constant for the name of the model context attribute backing property {@code enabled}.
*
* @see #processModel(org.jomc.modlet.ModelContext, org.jomc.modlet.Model)
* @see ModelContext#getAttribute(java.lang.String)
* @since 1.2
*/
public static final String ENABLED_ATTRIBUTE_NAME = "org.jomc.model.modlet.DefaultModelProcessor.enabledAttribute";
/**
* Constant for the name of the system property controlling property {@code defaultEnabled}.
*
* @see #isDefaultEnabled()
*/
private static final String DEFAULT_ENABLED_PROPERTY_NAME =
"org.jomc.model.modlet.DefaultModelProcessor.defaultEnabled";
/**
* Constant for the name of the deprecated system property controlling property {@code defaultEnabled}.
* @see #isDefaultEnabled()
*/
private static final String DEPRECATED_DEFAULT_ENABLED_PROPERTY_NAME =
"org.jomc.model.DefaultModelProcessor.defaultEnabled";
/**
* Default value of the flag indicating the processor is enabled by default.
*
* @see #isDefaultEnabled()
* @since 1.2
*/
private static final Boolean DEFAULT_ENABLED = Boolean.TRUE;
/**
* Flag indicating the processor is enabled by default.
*/
private static volatile Boolean defaultEnabled;
/**
* Flag indicating the processor is enabled.
*/
private Boolean enabled;
/**
* Constant for the name of the model context attribute backing property {@code transformerLocation}.
*
* @see #processModel(org.jomc.modlet.ModelContext, org.jomc.modlet.Model)
* @see ModelContext#getAttribute(java.lang.String)
* @since 1.2
*/
public static final String TRANSFORMER_LOCATION_ATTRIBUTE_NAME =
"org.jomc.model.modlet.DefaultModelProcessor.transformerLocationAttribute";
/**
* Constant for the name of the system property controlling property {@code defaultTransformerLocation}.
*
* @see #getDefaultTransformerLocation()
*/
private static final String DEFAULT_TRANSFORMER_LOCATION_PROPERTY_NAME =
"org.jomc.model.modlet.DefaultModelProcessor.defaultTransformerLocation";
/**
* Constant for the name of the deprecated system property controlling property {@code defaultTransformerLocation}.
* @see #getDefaultTransformerLocation()
*/
private static final String DEPRECATED_DEFAULT_TRANSFORMER_LOCATION_PROPERTY_NAME =
"org.jomc.model.DefaultModelProcessor.defaultTransformerLocation";
/**
* Class path location searched for transformers by default.
*
* @see #getDefaultTransformerLocation()
*/
private static final String DEFAULT_TRANSFORMER_LOCATION = "META-INF/jomc.xsl";
/**
* Default transformer location.
*/
private static volatile String defaultTransformerLocation;
/**
* Transformer location of the instance.
*/
private String transformerLocation;
/**
* Creates a new {@code DefaultModelProcessor} instance.
*/
public DefaultModelProcessor()
{
super();
}
/**
* Gets a flag indicating the processor is enabled by default.
* <p>
* The default enabled flag is controlled by system property
* {@code org.jomc.model.modlet.DefaultModelProcessor.defaultEnabled} holding a value indicating the processor is
* enabled by default. If that property is not set, the {@code true} default is returned.
* </p>
*
* @return {@code true}, if the processor is enabled by default; {@code false}, if the processor is disabled by
* default.
*
* @see #setDefaultEnabled(java.lang.Boolean)
*/
public static boolean isDefaultEnabled()
{
if ( defaultEnabled == null )
{
defaultEnabled =
Boolean.valueOf( System.getProperty( DEFAULT_ENABLED_PROPERTY_NAME,
System.getProperty( DEPRECATED_DEFAULT_ENABLED_PROPERTY_NAME,
Boolean.toString( DEFAULT_ENABLED ) ) ) );
}
return defaultEnabled;
}
/**
* Sets the flag indicating the processor is enabled by default.
*
* @param value The new value of the flag indicating the processor is enabled by default or {@code null}.
*
* @see #isDefaultEnabled()
*/
public static void setDefaultEnabled( final Boolean value )
{
defaultEnabled = value;
}
/**
* Gets a flag indicating the processor is enabled.
*
* @return {@code true}, if the processor is enabled; {@code false}, if the processor is disabled.
*
* @see #isDefaultEnabled()
* @see #setEnabled(java.lang.Boolean)
*/
public final boolean isEnabled()
{
if ( this.enabled == null )
{
this.enabled = isDefaultEnabled();
}
return this.enabled;
}
/**
* Sets the flag indicating the processor is enabled.
*
* @param value The new value of the flag indicating the processor is enabled or {@code null}.
*
* @see #isEnabled()
*/
public final void setEnabled( final Boolean value )
{
this.enabled = value;
}
/**
* Gets the default location searched for transformer resources.
* <p>
* The default transformer location is controlled by system property
* {@code org.jomc.model.modlet.DefaultModelProcessor.defaultTransformerLocation} holding the location to search for
* transformer resources by default. If that property is not set, the {@code META-INF/jomc.xsl} default is
* returned.
* </p>
*
* @return The location searched for transformer resources by default.
*
* @see #setDefaultTransformerLocation(java.lang.String)
*/
public static String getDefaultTransformerLocation()
{
if ( defaultTransformerLocation == null )
{
defaultTransformerLocation =
System.getProperty( DEFAULT_TRANSFORMER_LOCATION_PROPERTY_NAME,
System.getProperty( DEPRECATED_DEFAULT_TRANSFORMER_LOCATION_PROPERTY_NAME,
DEFAULT_TRANSFORMER_LOCATION ) );
}
return defaultTransformerLocation;
}
/**
* Sets the default location searched for transformer resources.
*
* @param value The new default location to search for transformer resources or {@code null}.
*
* @see #getDefaultTransformerLocation()
*/
public static void setDefaultTransformerLocation( final String value )
{
defaultTransformerLocation = value;
}
/**
* Gets the location searched for transformer resources.
*
* @return The location searched for transformer resources.
*
* @see #getDefaultTransformerLocation()
* @see #setTransformerLocation(java.lang.String)
*/
public final String getTransformerLocation()
{
if ( this.transformerLocation == null )
{
this.transformerLocation = getDefaultTransformerLocation();
}
return this.transformerLocation;
}
/**
* Sets the location searched for transformer resources.
*
* @param value The new location to search for transformer resources or {@code null}.
*
* @see #getTransformerLocation()
*/
public final void setTransformerLocation( final String value )
{
this.transformerLocation = value;
}
/**
* Searches a given context for transformers.
*
* @param context The context to search for transformers.
* @param location The location to search at.
*
* @return The transformers found at {@code location} in {@code context} or {@code null}, if no transformers are
* found.
*
* @throws NullPointerException if {@code context} or {@code location} is {@code null}.
* @throws ModelException if getting the transformers fails.
*/
public List<Transformer> findTransformers( final ModelContext context, final String location ) throws ModelException
{
if ( context == null )
{
throw new NullPointerException( "context" );
}
if ( location == null )
{
throw new NullPointerException( "location" );
}
try
{
final long t0 = System.currentTimeMillis();
final List<Transformer> transformers = new LinkedList<Transformer>();
final TransformerFactory transformerFactory = TransformerFactory.newInstance();
final Enumeration<URL> resources = context.findResources( location );
final ErrorListener errorListener = new ErrorListener()
{
public void warning( final TransformerException exception ) throws TransformerException
{
if ( context.isLoggable( Level.WARNING ) )
{
context.log( Level.WARNING, getMessage( exception ), exception );
}
}
public void error( final TransformerException exception ) throws TransformerException
{
if ( context.isLoggable( Level.SEVERE ) )
{
context.log( Level.SEVERE, getMessage( exception ), exception );
}
throw exception;
}
public void fatalError( final TransformerException exception ) throws TransformerException
{
if ( context.isLoggable( Level.SEVERE ) )
{
context.log( Level.SEVERE, getMessage( exception ), exception );
}
throw exception;
}
};
transformerFactory.setErrorListener( errorListener );
int count = 0;
while ( resources.hasMoreElements() )
{
count++;
final URL url = resources.nextElement();
if ( context.isLoggable( Level.FINEST ) )
{
context.log( Level.FINEST, getMessage( "processing", url.toExternalForm() ), null );
}
final Transformer transformer =
transformerFactory.newTransformer( new StreamSource( url.toURI().toASCIIString() ) );
transformer.setErrorListener( errorListener );
for ( final Map.Entry<Object, Object> e : System.getProperties().entrySet() )
{
transformer.setParameter( e.getKey().toString(), e.getValue() );
}
transformers.add( transformer );
}
if ( context.isLoggable( Level.FINE ) )
{
context.log( Level.FINE, getMessage( "contextReport", count, location,
Long.valueOf( System.currentTimeMillis() - t0 ) ), null );
}
return transformers.isEmpty() ? null : transformers;
}
catch ( final URISyntaxException e )
{
throw new ModelException( getMessage( e ), e );
}
catch ( final TransformerConfigurationException e )
{
String message = getMessage( e );
if ( message == null && e.getException() != null )
{
message = getMessage( e.getException() );
}
throw new ModelException( message, e );
}
}
/**
* {@inheritDoc}
*
* @see #isEnabled()
* @see #getTransformerLocation()
* @see #findTransformers(org.jomc.modlet.ModelContext, java.lang.String)
* @see #ENABLED_ATTRIBUTE_NAME
* @see #TRANSFORMER_LOCATION_ATTRIBUTE_NAME
*/
public Model processModel( final ModelContext context, final Model model ) throws ModelException
{
if ( context == null )
{
throw new NullPointerException( "context" );
}
if ( model == null )
{
throw new NullPointerException( "model" );
}
try
{
Model processed = model;
boolean contextEnabled = this.isEnabled();
if ( DEFAULT_ENABLED == contextEnabled
&& context.getAttribute( ENABLED_ATTRIBUTE_NAME ) instanceof Boolean )
{
contextEnabled = (Boolean) context.getAttribute( ENABLED_ATTRIBUTE_NAME );
}
String contextTransformerLocation = this.getTransformerLocation();
if ( DEFAULT_TRANSFORMER_LOCATION.equals( contextTransformerLocation )
&& context.getAttribute( TRANSFORMER_LOCATION_ATTRIBUTE_NAME ) instanceof String )
{
contextTransformerLocation = (String) context.getAttribute( TRANSFORMER_LOCATION_ATTRIBUTE_NAME );
}
if ( contextEnabled )
{
final org.jomc.modlet.ObjectFactory objectFactory = new org.jomc.modlet.ObjectFactory();
final JAXBContext jaxbContext = context.createContext( model.getIdentifier() );
final List<Transformer> transformers = this.findTransformers( context, contextTransformerLocation );
processed = model.clone();
if ( transformers != null )
{
for ( int i = 0, s0 = transformers.size(); i < s0; i++ )
{
final JAXBElement<Model> e = objectFactory.createModel( processed );
final JAXBSource source = new JAXBSource( jaxbContext, e );
final JAXBResult result = new JAXBResult( jaxbContext );
transformers.get( i ).transform( source, result );
if ( result.getResult() instanceof JAXBElement<?>
&& ( (JAXBElement<?>) result.getResult() ).getValue() instanceof Model )
{
processed = (Model) ( (JAXBElement<?>) result.getResult() ).getValue();
}
else
{
throw new ModelException( getMessage(
"illegalTransformationResult", model.getIdentifier() ) );
}
}
}
}
else if ( context.isLoggable( Level.FINER ) )
{
context.log( Level.FINER, getMessage( "disabled", this.getClass().getSimpleName(),
model.getIdentifier() ), null );
}
return processed;
}
catch ( final TransformerException e )
{
String message = getMessage( e );
if ( message == null && e.getException() != null )
{
message = getMessage( e.getException() );
}
throw new ModelException( message, e );
}
catch ( final JAXBException e )
{
String message = getMessage( e );
if ( message == null && e.getLinkedException() != null )
{
message = getMessage( e.getLinkedException() );
}
throw new ModelException( message, e );
}
}
private static String getMessage( final String key, final Object... args )
{
return MessageFormat.format( ResourceBundle.getBundle(
DefaultModelProcessor.class.getName().replace( '.', '/' ), Locale.getDefault() ).getString( key ), args );
}
private static String getMessage( final Throwable t )
{
return t != null
? t.getMessage() != null && t.getMessage().trim().length() > 0
? t.getMessage()
: getMessage( t.getCause() )
: null;
}
}