ClassDescriptorImpl

/**
 * Redistribution and use of this software and associated documentation
 * ("Software"), with or without modification, are permitted provided
 * that the following conditions are met:
 *
 * 1. Redistributions of source code must retain copyright
 *    statements and notices.  Redistributions must also contain a
 *    copy of this document.
 *
 * 2. 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.
 *
 * 3. The name "Exolab" must not be used to endorse or promote
 *    products derived from this Software without prior written
 *    permission of Intalio, Inc.  For written permission,
 *    please contact info@exolab.org.
 *
 * 4. Products derived from this Software may not be called "Exolab"
 *    nor may "Exolab" appear in their names without prior written
 *    permission of Intalio, Inc. Exolab is a registered
 *    trademark of Intalio, Inc.
 *
 * 5. Due credit should be given to the Exolab Project
 *    (http://www.exolab.org/).
 *
 * THIS SOFTWARE IS PROVIDED BY INTALIO, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESSED 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
 * INTALIO, INC. OR ITS CONTRIBUTORS 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.
 *
 * Copyright 1999 (C) Intalio, Inc. All Rights Reserved.
 *
 * $Id$
 */
package org.exolab.castor.mapping.loader;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import org.exolab.castor.mapping.ClassDescriptor;
import org.exolab.castor.mapping.FieldDescriptor;
import org.exolab.castor.mapping.xml.ClassMapping;

/**
 * The standard {@link ClassDescriptor} implementation, holding general OO information
 * about the class <i>described</i>.<p/>
 *
 * Engines will use {@link Nature}s to augment this class with engine-specific knowledge
 * and functionality, using {@link #addNature(String)} to register these views
 * with this class.<p/>
 *
 * Once a Nature has been registered with this {@link ClassDescriptor}, the nature
 * can be applied to the {@link ClassDescriptor} and nature-specific properties
 * can be accessed in a type-safe way.
 *
 * @see Nature
 * @see #addNature(String)
 * @see #hasNature(String)
 *
 * @author <a href="mailto:arkin AT intalio DOT com">Assaf Arkin</a>
 * @author <a href="mailto:ralf DOT joachim AT syscon DOT eu">Ralf Joachim</a>
 * @author <a href="mailto:wguttmn AT codehaus DOT org">Werner Guttmann</a>
 * @version $Revision$ $Date: 2006-01-07 15:48:31 -0700 (Sat, 07 Jan 2006) $
 */
public class ClassDescriptorImpl implements ClassDescriptor {

    /**
     * {@link ClassMapping} instance holding class mapping information required
     * during initialisation of e.g. (JDO) ClassMolder.
     */
    private ClassMapping _mapping;

    /**
     * The Java class for this descriptor.
     */
    private Class<?> _javaClass;

    /**
     * The descriptor of the class which this class extends,
     * or null if this is a top-level class.
     */
    private ClassDescriptor _extends;

    /**
     * The {@link ClassDescriptor} of the class which this class
     * depends upon.
     */
    private ClassDescriptor _depends;

    /** #
     * The fields described for this class.
     */
    private FieldDescriptor[] _fields;

    /**
     * Map holding the properties set and read by natures.
     */
    private Map<String, Object> _properties = new HashMap<String, Object>();

    /**
     * Map holding the available natures.
     */
    private Set<String> _natures = new HashSet<String>();

   /**
     * Identity {@link FieldDescriptor}s.
     */
    private FieldDescriptor[] _identities;

    /**
     * Sets the {@link ClassMapping} instance.
     * @param mapping The {@link ClassMapping} instance to be used.
     */
    public void setMapping(final ClassMapping mapping) {
        _mapping = mapping;
    }

    /**
     * Returns the {@link ClassMapping} instance used.
     * @return The {@link ClassMapping} instance used.
     */
    public ClassMapping getMapping() {
        return _mapping;
    }

    /**
     * Sets the Java {@link Class} as described by this descriptor.
     * @param javaClass The Java {@link Class} instance as described by this descriptor.
     */
    public void setJavaClass(final Class<?> javaClass) {
        _javaClass = javaClass;
    }

    /**
     * {@inheritDoc}
     *
     * @see org.exolab.castor.mapping.ClassDescriptor#getJavaClass()
     */
    public Class<?> getJavaClass() {
        return _javaClass;
    }

    /**
     * Sets the descriptor of the class which this class extends.
     * @param extend the descriptor of the class which this class extends.
     */
    public void setExtends(final ClassDescriptor extend) {
        _extends = extend;
    }

    /**
     * {@inheritDoc}
     *
     * @see org.exolab.castor.mapping.ClassDescriptor#getExtends()
     */
    public ClassDescriptor getExtends() {
        return _extends;
    }

    /**
     * Sets the {@link ClassDescriptor} of the class which this class
     * depends upon.
     * @param depends the {@link ClassDescriptor} of the class which this class
     * depends upon
     */
    public void setDepends(final ClassDescriptor depends) {
        _depends = depends;
    }

    /**
     * Returns the {@link ClassDescriptor} of the class which this class
     * depends upon.
     * @return the {@link ClassDescriptor} of the class which this class
     * depends upon.
     */
    public ClassDescriptor getDepends() {
        return _depends;
    }

    /**
     * Sets the {@link FieldDescriptor}s that describe the fields defined for this class.
     * @param fields the {@link FieldDescriptor}s that describe the fields defined for this class.
     */
    public void setFields(final FieldDescriptor[] fields) {
        _fields = fields;
    }

    /**
     * {@inheritDoc}
     * @see org.exolab.castor.mapping.ClassDescriptor#getFields()
     */
    public FieldDescriptor[] getFields() {
        return _fields;
    }

    /**
     * {@inheritDoc}
     * @see java.lang.Object#toString()
     */
    public String toString() {
        return _javaClass.getName() + "[" + _natures.toString() + "]";
    }

    /**
     * @see org.exolab.castor.builder.info.nature.PropertyHolder#
     *      getProperty(java.lang.String)
     * @param name
     *            of the property
     * @return value of the property
     */
    public Object getProperty(final String name) {
        return _properties.get(name);
    }

    /**
     * @see org.exolab.castor.builder.info.nature.PropertyHolder#
     *      setProperty(java.lang.String, java.lang.Object)
     * @param name
     *            of the property
     * @param value
     *            of the property
     */
    public void setProperty(final String name, final Object value) {
        _properties.put(name, value);
    }

    /**
     * @see org.exolab.castor.builder.info.nature.NatureExtendable#
     *      addNature(java.lang.String)
     * @param nature
     *            ID of the Nature
     */
    public void addNature(final String nature) {
        _natures.add(nature);
    }

    /**
     * @see org.exolab.castor.builder.info.nature.NatureExtendable#
     *      hasNature(java.lang.String)
     * @param nature
     *            ID of the Nature
     * @return true if the Nature ID was added.
     */
    public boolean hasNature(final String nature) {
        return _natures.contains(nature);

    }

    /**
     * Sets the {@link FieldDescriptor}s that describe the identities as defined for this class.
     * @param identities the {@link FieldDescriptor}s that describe the identities as defined
     *     for this class.
     */
    public void setIdentities(final FieldDescriptor[] identities) {
        _identities = identities;
    }

    /**
     * Returns the {@link FieldDescriptor}s that describe the identities as defined for this class.
     * @return the {@link FieldDescriptor}s that describe the identities as defined for this class.
     */
    public FieldDescriptor[] getIdentities() {
        return _identities;
    }

    /**
     * Returns the first {@link FieldDescriptor} instance.
     * @return the first {@link FieldDescriptor} instance
     */
    public FieldDescriptor getIdentity() {
        FieldDescriptor[] identities = getIdentities();
        if (identities == null) {
            return null;
        }
        return identities[0];
    }


}