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
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 * 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 + ']';
  }

  /**
   * @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];
  }


}