package org.exolab.castor.mapping.loader;
   
   import java.util.Comparator;
   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.FieldHandler;
  import org.exolab.castor.mapping.xml.types.FieldMappingCollectionType;
  
  public class FieldDescriptorImpl implements FieldDescriptor {
  
    /** A reference to the containing class descriptor (parent). */
    private ClassDescriptor _parent;
  
    /** The name of the field. */
    private String _fieldName;
  
    /** The type of the field. */
    private Class<?> _fieldType;
  
    /** The type class descriptor, if this field is of a type known by a descriptor. */
    private ClassDescriptor _classDescriptor;
  
    /** The field handler for get/set field value. */
    private FieldHandler _handler;
  
    /** True if the field is transient and should not be saved/stored. */
    private boolean _transient;
  
    /** True if the described field type is immutable. */
    private boolean _immutable;
  
    /** True if the field type is required. */
    private boolean _required;
  
    /** True if access to field is direct. */
    private boolean _direct;
  
    /** True if access to field is lazy. */
    private boolean _lazy;
  
    /** True if the object described by this descriptor is multi-valued. */
    private boolean _multivalued;
  
    /** True if the field is part of the identity of the class. */
    private boolean _identity;
  
    /** The name of a class that implements the {@link Comparator} interface. */
    private String _comparator;
  
    /** The name of the 'getter' method used to obtain the value of a property. */
    private String _getMethod;
  
    /** The name of the 'setter' method used to set the value of a property. */
    private String _setMethod;
  
    /** The name of the 'create' method used to create an instance of a property. */
    private String _createMethod;
  
    /** The type of the collection, if the field is multi-valued. */
    private FieldMappingCollectionType _collection;
  
    /**
     * 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>();
  
    /**
     * Creates a default instance of a field descriptor.
     */
    protected FieldDescriptorImpl() {}
  
    /**
     * Constructs a new field descriptor.
     *
     * @param fieldName The field name
     * @param typeInfo The field type information
     * @param handler The field handler (may be null)
     * @param isTransitive True if the field is transient
     */
    public FieldDescriptorImpl(final String fieldName, final TypeInfo typeInfo,
        final FieldHandler handler, final boolean isTransitive) {
  
      if (fieldName == null) {
        throw new IllegalArgumentException("Internal error. Field name not specified.");
      }
  
      if (handler == null) {
        throw new IllegalArgumentException("Internal error. No FieldHandler provided.");
      }
 
     setFieldName(fieldName);
     setFieldType(typeInfo.getFieldType());
     setHandler(handler);
     setTransient(isTransitive);
     setImmutable(typeInfo.isImmutable());
     setRequired(typeInfo.isRequired());
     setMultivalued(typeInfo.getCollectionHandler() != null);
   }
 
   /**
    * @see org.exolab.castor.mapping.FieldDescriptor#setContainingClassDescriptor(
    *      org.exolab.castor.mapping.ClassDescriptor) {@inheritDoc}
    */
   public final void setContainingClassDescriptor(final ClassDescriptor parent) {
     _parent = parent;
   }
 
   /**
    * @see org.exolab.castor.mapping.FieldDescriptor#getContainingClassDescriptor() {@inheritDoc}
    */
   public final ClassDescriptor getContainingClassDescriptor() {
     return _parent;
   }
 
   /**
    * Set the name of the field.
    * 
    * @param fieldName Field name.
    */
   public final void setFieldName(final String fieldName) {
     _fieldName = fieldName;
   }
 
   /**
    * @see org.exolab.castor.mapping.FieldDescriptor#getFieldName() {@inheritDoc}
    */
   public final String getFieldName() {
     return _fieldName;
   }
 
   /**
    * Set the type of the field.
    * 
    * @param fieldType Field type.
    */
   public final void setFieldType(final Class<?> fieldType) {
     _fieldType = fieldType;
   }
 
   /**
    * @see org.exolab.castor.mapping.FieldDescriptor#getFieldType() {@inheritDoc}
    */
   public final Class<?> getFieldType() {
     return _fieldType;
   }
 
   /**
    * Set the ClassDescriptor for the described field.
    *
    * @param classDescriptor The ClassDescriptor for the described field.
    */
   public final void setClassDescriptor(final ClassDescriptor classDescriptor) {
     _classDescriptor = classDescriptor;
   }
 
   /**
    * @see org.exolab.castor.mapping.FieldDescriptor#getClassDescriptor() {@inheritDoc}
    */
   public final ClassDescriptor getClassDescriptor() {
     return _classDescriptor;
   }
 
   /**
    * Set the FieldHandler for the field being described by this FieldDescriptor.
    *
    * @param handler The FieldHandler for the field being described.
    */
   public final void setHandler(final FieldHandler handler) {
     _handler = handler;
   }
 
   /**
    * @see org.exolab.castor.mapping.FieldDescriptor#getHandler() {@inheritDoc}
    */
   public final FieldHandler getHandler() {
     return _handler;
   }
 
   /**
    * Sets whether or not the describled field is 'transient'.
    * 
    * @param isTransient The flag indicating if the described field is 'transient'.
    */
   public final void setTransient(final boolean isTransient) {
     _transient = isTransient;
   }
 
   /**
    * @see org.exolab.castor.mapping.FieldDescriptor#isTransient() {@inheritDoc}
    */
   public final boolean isTransient() {
     return _transient;
   }
 
   /**
    * Set the immutable flag which indicates that changes to this Field result in a new Object to be
    * created, such as java.lang.String. It serves to identify fields which should not be constructed
    * until all the data is available.
    * 
    * @param immutable Flag which if true indicates that the field is immutable.
    */
   public final void setImmutable(final boolean immutable) {
     _immutable = immutable;
   }
 
   /**
    * @see org.exolab.castor.mapping.FieldDescriptor#isImmutable() {@inheritDoc}
    */
   public final boolean isImmutable() {
     return _immutable;
   }
 
   /**
    * Set whether or not the described field is required.
    * 
    * @param required The flag indicating whether or not the described field is required.
    */
   public final void setRequired(final boolean required) {
     _required = required;
   }
 
   /**
    * @see org.exolab.castor.mapping.FieldDescriptor#isRequired() {@inheritDoc}
    */
   public final boolean isRequired() {
     return _required;
   }
 
   /**
    * Set wheter the object described by this descriptor is multivalued or not.
    * 
    * @param multivalued True if the object described by this descriptor is multivalued.
    */
   public final void setMultivalued(final boolean multivalued) {
     _multivalued = multivalued;
   }
 
   /**
    * @see org.exolab.castor.mapping.FieldDescriptor#isMultivalued() {@inheritDoc}
    */
   public final boolean isMultivalued() {
     return _multivalued;
   }
 
   /**
    * Set wether the described field is part of the identity of the class it belongs to.
    * 
    * @param identity <code>true</code> if field is part of the classes identity.
    */
   public final void setIdentity(final boolean identity) {
     _identity = identity;
   }
 
   /**
    * Is the described field is part of the identity of the class it belongs to?
    * 
    * @return <code>true</code> if field is part of the classes identity.
    */
   public final boolean isIdentity() {
     return _identity;
   }
 
   /**
    * @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);
   }
 
   public String getComparator() {
     return _comparator;
   }
 
   public void setComparator(String comparator) {
     _comparator = comparator;
   }
 
   public FieldMappingCollectionType getCollection() {
     return _collection;
   }
 
   public void setCollection(FieldMappingCollectionType collection) {
     _collection = collection;
   }
 
   public boolean isDirect() {
     return _direct;
   }
 
   public void setDirect(boolean direct) {
     _direct = direct;
   }
 
   public String getGetMethod() {
     return _getMethod;
   }
 
   public void setGetMethod(String getMethod) {
     _getMethod = getMethod;
   }
 
   public String getSetMethod() {
     return _setMethod;
   }
 
   public void setSetMethod(String setMethod) {
     _setMethod = setMethod;
   }
 
   public String getCreateMethod() {
     return _createMethod;
   }
 
   public void setCreateMethod(String createMethod) {
     _createMethod = createMethod;
   }
 
   public boolean isLazy() {
     return _lazy;
   }
 
   public void setLazy(boolean lazy) {
     _lazy = lazy;
   }
 
   public String toString() {
     return new StringBuilder().append(getFieldName()).append('(').append(getFieldType().getName())
         .append(')').toString();
     // TODO[WG]: find a way to emit additional nature-specific information.
     // try {
     // Class natureClass =
     // Class.forName("org.exolab.castor.jdo.engine.nature.FieldDescriptorJDONature");
     // if (hasNature(natureClass.getName())) {
     // FieldDescriptorJDONature jdoNature = new FieldDescriptorJDONature(this);
     // buffer.append(jdoNature.getSQLName() == null ? "" : " AS "
     // + jdoNature.getSQLName()[0]);
     // }
     // } catch (ClassNotFoundException e) {
     // // ignore
     // }
   }
 
 }