/* ========================================================================
* JCommon : a free general purpose class library for the Java(tm) platform
* ========================================================================
*
* (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
*
* Project Info: http://www.jfree.org/jcommon/index.html
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*
* [Java is a trademark or registered trademark of Sun Microsystems, Inc.
* in the United States and other countries.]
*
* ------------------------
* ObjectFactoryLoader.java
* ------------------------
* (C) Copyright 2002-2005, by Thomas Morgner and Contributors.
*
* Original Author: Thomas Morgner;
* Contributor(s): -;
*
* $Id: ObjectFactoryLoader.java,v 1.4 2005/10/18 13:33:53 mungady Exp $
*
* Changes
* -------
* 24-Sep-2003: Initial version
*
*/
package org.jfree.xml.util;
import java.net.URL;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Iterator;
import org.jfree.util.Log;
import org.jfree.xml.attributehandlers.AttributeHandler;
/**
* The object factory loader loads the xml specification for the generic
* handlers. The specification may be distributed over multiple files.
* <p>
* This class provides the model management for the reader and writer.
* The instantiation of the handlers is done elsewhere.
*
* @author TM
*/
public class ObjectFactoryLoader extends AbstractModelReader implements ObjectFactory {
/** Maps classes to GenericObjectFactory instances. */
private HashMap objectMappings;
/** Manual mappings. */
private HashMap manualMappings;
/** Multiplex mappings. */
private HashMap multiplexMappings;
/** The target class. */
private Class target;
/** The register name. */
private String registerName;
/** The property definition. */
private ArrayList propertyDefinition;
/** The attribute definition. */
private ArrayList attributeDefinition;
/** The constructor definition. */
private ArrayList constructorDefinition;
/** The lookup definitions. */
private ArrayList lookupDefinitions;
/** The ordered names. */
private ArrayList orderedNames;
/** The base class. */
private String baseClass;
/** The attribute name. */
private String attributeName;
/** The multiplex entries. */
private ArrayList multiplexEntries;
/**
* Creates a new object factory loader for the given base file.
*
* @param resourceName the URL of the initial specification file.
*
* @throws ObjectDescriptionException if the file could not be parsed.
*/
public ObjectFactoryLoader(final URL resourceName) throws ObjectDescriptionException {
this.objectMappings = new HashMap();
this.manualMappings = new HashMap();
this.multiplexMappings = new HashMap();
parseXml(resourceName);
rebuildSuperClasses();
}
private void rebuildSuperClasses() throws ObjectDescriptionException {
this.propertyDefinition = new ArrayList();
this.attributeDefinition = new ArrayList();
this.constructorDefinition = new ArrayList();
this.lookupDefinitions = new ArrayList();
this.orderedNames = new ArrayList();
final HashMap newObjectDescriptions = new HashMap();
final Iterator it = this.objectMappings.keySet().iterator();
while (it.hasNext()) {
final Object key = it.next();
final GenericObjectFactory gef = (GenericObjectFactory) this.objectMappings.get(key);
performSuperClassUpdate(gef);
final PropertyDefinition[] propertyDefs = (PropertyDefinition[])
this.propertyDefinition.toArray(new PropertyDefinition[0]);
final LookupDefinition[] lookupDefs = (LookupDefinition[])
this.lookupDefinitions.toArray(new LookupDefinition[0]);
final AttributeDefinition[] attribDefs = (AttributeDefinition[])
this.attributeDefinition.toArray(new AttributeDefinition[0]);
final ConstructorDefinition[] constructorDefs = (ConstructorDefinition[])
this.constructorDefinition.toArray(new ConstructorDefinition[0]);
final String[] orderedNamesDefs = (String[])
this.orderedNames.toArray(new String[0]);
final GenericObjectFactory objectFactory = new GenericObjectFactory
(gef.getBaseClass(), gef.getRegisterName(), constructorDefs,
propertyDefs, lookupDefs, attribDefs, orderedNamesDefs);
newObjectDescriptions.put(key, objectFactory);
this.propertyDefinition.clear();
this.attributeDefinition.clear();
this.constructorDefinition.clear();
this.lookupDefinitions.clear();
this.orderedNames.clear();
}
this.objectMappings.clear();
this.objectMappings = newObjectDescriptions;
this.propertyDefinition = null;
this.attributeDefinition = null;
this.constructorDefinition = null;
this.lookupDefinitions = null;
this.orderedNames = null;
}
private void performSuperClassUpdate(final GenericObjectFactory gef) {
// first handle the super classes, ...
final Class superClass = gef.getBaseClass().getSuperclass();
if (superClass != null && !superClass.equals(Object.class)) {
final GenericObjectFactory superGef = (GenericObjectFactory) this.objectMappings.get(
superClass
);
if (superGef != null) {
performSuperClassUpdate(superGef);
}
}
// and finally append all local properties ...
this.propertyDefinition.addAll(Arrays.asList(gef.getPropertyDefinitions()));
this.attributeDefinition.addAll(Arrays.asList(gef.getAttributeDefinitions()));
this.constructorDefinition.addAll(Arrays.asList(gef.getConstructorDefinitions()));
this.lookupDefinitions.addAll(Arrays.asList(gef.getLookupDefinitions()));
this.orderedNames.addAll(Arrays.asList(gef.getOrderedPropertyNames()));
}
/**
* Starts a object definition. The object definition collects all properties of
* an bean-class and defines, which constructor should be used when creating the
* class.
*
* @param className the class name of the defined object
* @param register the (optional) register name, to lookup and reference the object later.
* @param ignore ignore?
*
* @return true, if the definition was accepted, false otherwise.
* @throws ObjectDescriptionException if an unexpected error occured.
*/
protected boolean startObjectDefinition(final String className, final String register, final boolean ignore)
throws ObjectDescriptionException {
if (ignore) {
return false;
}
this.target = loadClass(className);
if (this.target == null) {
Log.warn(new Log.SimpleMessage("Failed to load class ", className));
return false;
}
this.registerName = register;
this.propertyDefinition = new ArrayList();
this.attributeDefinition = new ArrayList();
this.constructorDefinition = new ArrayList();
this.lookupDefinitions = new ArrayList();
this.orderedNames = new ArrayList();
return true;
}
/**
* Handles an attribute definition. This method gets called after the object definition
* was started. The method will be called for every defined attribute property.
*
* @param name the name of the property
* @param attribName the xml-attribute name to use later.
* @param handlerClass the attribute handler class.
* @throws ObjectDescriptionException if an error occured.
*/
protected void handleAttributeDefinition(final String name, final String attribName, final String handlerClass)
throws ObjectDescriptionException {
final AttributeHandler handler = loadAttributeHandler(handlerClass);
this.orderedNames.add(name);
this.attributeDefinition.add(new AttributeDefinition(name, attribName, handler));
}
/**
* Handles an element definition. This method gets called after the object definition
* was started. The method will be called for every defined element property. Element
* properties are used to describe complex objects.
*
* @param name the name of the property
* @param element the xml-tag name for the child element.
* @throws ObjectDescriptionException if an error occurs.
*/
protected void handleElementDefinition(final String name, final String element)
throws ObjectDescriptionException {
this.orderedNames.add(name);
this.propertyDefinition.add(new PropertyDefinition(name, element));
}
/**
* Handles an lookup definition. This method gets called after the object definition
* was started. The method will be called for every defined lookup property. Lookup properties
* reference previously created object using the object's registry name.
*
* @param name the property name of the base object
* @param lookupKey the register key of the referenced object
* @throws ObjectDescriptionException if an error occured.
*/
protected void handleLookupDefinition(final String name, final String lookupKey)
throws ObjectDescriptionException {
final LookupDefinition ldef = new LookupDefinition(name, lookupKey);
this.orderedNames.add(name);
this.lookupDefinitions.add(ldef);
}
/**
* Finializes the object definition.
*
* @throws ObjectDescriptionException if an error occures.
*/
protected void endObjectDefinition()
throws ObjectDescriptionException {
final PropertyDefinition[] propertyDefs = (PropertyDefinition[])
this.propertyDefinition.toArray(new PropertyDefinition[0]);
final LookupDefinition[] lookupDefs = (LookupDefinition[])
this.lookupDefinitions.toArray(new LookupDefinition[0]);
final AttributeDefinition[] attribDefs = (AttributeDefinition[])
this.attributeDefinition.toArray(new AttributeDefinition[0]);
final ConstructorDefinition[] constructorDefs = (ConstructorDefinition[])
this.constructorDefinition.toArray(new ConstructorDefinition[0]);
final String[] orderedNamesDefs = (String[])
this.orderedNames.toArray(new String[0]);
final GenericObjectFactory objectFactory = new GenericObjectFactory
(this.target, this.registerName, constructorDefs,
propertyDefs, lookupDefs, attribDefs, orderedNamesDefs);
this.objectMappings.put(this.target, objectFactory);
}
/**
* Handles a constructor definition. Only one constructor can be defined for
* a certain object type. The constructor will be filled using the given properties.
*
* @param propertyName the property name of the referenced local property
* @param parameterClass the parameter class for the parameter.
*/
protected void handleConstructorDefinition(final String propertyName, final String parameterClass) {
final Class c = loadClass(parameterClass);
this.orderedNames.add(propertyName);
this.constructorDefinition.add(new ConstructorDefinition(propertyName, c));
}
/**
* Handles a manual mapping definition. The manual mapping maps specific
* read and write handlers to a given base class. Manual mappings always
* override any other definition.
*
* @param className the base class name
* @param readHandler the class name of the read handler
* @param writeHandler the class name of the write handler
* @return true, if the mapping was accepted, false otherwise.
* @throws ObjectDescriptionException if an unexpected error occured.
*/
protected boolean handleManualMapping(final String className, final String readHandler, final String writeHandler)
throws ObjectDescriptionException {
if (!this.manualMappings.containsKey(className)) {
final Class loadedClass = loadClass(className);
this.manualMappings.put(loadedClass, new ManualMappingDefinition
(loadedClass, readHandler, writeHandler));
return true;
}
return false;
}
/**
* Starts a multiplex mapping. Multiplex mappings are used to define polymorphic
* argument handlers. The mapper will collect all derived classes of the given
* base class and will select the corresponding mapping based on the given type
* attribute.
*
* @param className the base class name
* @param typeAttr the xml-attribute name containing the mapping key
*/
protected void startMultiplexMapping(final String className, final String typeAttr) {
this.baseClass = className;
this.attributeName = typeAttr;
this.multiplexEntries = new ArrayList();
}
/**
* Defines an entry for the multiplex mapping. The new entry will be activated
* when the base mappers type attribute contains this <code>typename</code> and
* will resolve to the handler for the given classname.
*
* @param typeName the type value for this mapping.
* @param className the class name to which this mapping resolves.
* @throws ObjectDescriptionException if an error occurs.
*/
protected void handleMultiplexMapping(final String typeName, final String className)
throws ObjectDescriptionException {
this.multiplexEntries.add
(new MultiplexMappingEntry(typeName, className));
}
/**
* Finializes the multiplexer mapping.
*
* @throws ObjectDescriptionException if an error occurs.
*/
protected void endMultiplexMapping() throws ObjectDescriptionException {
final MultiplexMappingEntry[] mappings = (MultiplexMappingEntry[])
this.multiplexEntries.toArray(new MultiplexMappingEntry[0]);
final Class c = loadClass(this.baseClass);
this.multiplexMappings.put(c,
new MultiplexMappingDefinition(c, this.attributeName, mappings));
this.multiplexEntries = null;
}
/**
* Loads an instantiates the attribute handler specified by the given
* class name.
*
* @param attribute the attribute handlers classname.
* @return the created attribute handler instance
* @throws ObjectDescriptionException if the handler could not be loaded.
*/
private AttributeHandler loadAttributeHandler(final String attribute)
throws ObjectDescriptionException {
final Class c = loadClass(attribute);
try {
return (AttributeHandler) c.newInstance();
}
catch (Exception e) {
throw new ObjectDescriptionException
("Invalid attribute handler specified: " + attribute);
}
}
/**
* Checks, whether the factory has a description for the given class.
*
* @param c the class to be handled by the factory.
* @return true, if an description exists for the given class, false otherwise.
*/
public boolean isGenericHandler(final Class c) {
return this.objectMappings.containsKey(c);
}
/**
* Returns a factory instance for the given class. The factory is independent
* from all previously generated instances.
*
* @param c the class
* @return the object factory.
*/
public GenericObjectFactory getFactoryForClass(final Class c) {
final GenericObjectFactory factory = (GenericObjectFactory) this.objectMappings.get(c);
if (factory == null) {
return null;
}
return factory.getInstance();
}
/**
* Returns the manual mapping definition for the given class, or null, if
* not manual definition exists.
*
* @param c the class for which to check the existence of the definition
* @return the manual mapping definition or null.
*/
public ManualMappingDefinition getManualMappingDefinition(final Class c) {
return (ManualMappingDefinition) this.manualMappings.get(c);
}
/**
* Returns the multiplex definition for the given class, or null, if no
* such definition exists.
*
* @param c the class for which to check the existence of the multiplexer
* @return the multiplexer for the class, or null if no multiplexer exists.
*/
public MultiplexMappingDefinition getMultiplexDefinition(final Class c) {
final MultiplexMappingDefinition definition = (MultiplexMappingDefinition)
this.multiplexMappings.get(c);
return definition;
}
}