src/java.xml.ws/share/classes/com/sun/xml/internal/ws/policy/sourcemodel/ModelNode.java - platform/libcore - Gitiles

 /*
  * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this
  * particular file as subject to the "Classpath" exception as provided
  * by Oracle in the LICENSE file that accompanied this code.
  *
  * This code 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 General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */

 package com.sun.xml.internal.ws.policy.sourcemodel;

 import com.sun.xml.internal.ws.policy.privateutil.LocalizationMessages;
 import com.sun.xml.internal.ws.policy.privateutil.PolicyLogger;
 import com.sun.xml.internal.ws.policy.privateutil.PolicyUtils;
 import com.sun.xml.internal.ws.policy.sourcemodel.wspolicy.XmlToken;

 import java.util.Collection;
 import java.util.Collections;
 import java.util.Iterator;
 import java.util.LinkedList;

 /**
  * The general representation of a single node within a {@link com.sun.xml.internal.ws.policy.sourcemodel.PolicySourceModel} instance.
  * The model node is created via factory methods of the {@link com.sun.xml.internal.ws.policy.sourcemodel.PolicySourceModel} instance.
  * It may also hold {@link com.sun.xml.internal.ws.policy.sourcemodel.AssertionData} instance in case its type is {@code ModelNode.Type.ASSERTION}.
  *
  * @author Marek Potociar
  */
 public final class ModelNode implements Iterable<ModelNode>, Cloneable {
     private static final PolicyLogger LOGGER = PolicyLogger.getLogger(ModelNode.class);

     /**
      * Policy source model node type enumeration
      */
     public static enum Type {
         POLICY(XmlToken.Policy),
         ALL(XmlToken.All),
         EXACTLY_ONE(XmlToken.ExactlyOne),
         POLICY_REFERENCE(XmlToken.PolicyReference),
         ASSERTION(XmlToken.UNKNOWN),
         ASSERTION_PARAMETER_NODE(XmlToken.UNKNOWN);

         private XmlToken token;

         Type(XmlToken token) {
             this.token = token;
         }

         public XmlToken getXmlToken() {
             return token;
         }

         /**
          * Method checks the PSM state machine if the creation of new child of given type is plausible for a node element
          * with type set to this type instance.
          *
          * @param childType The type.
          * @return True if the type is supported, false otherwise
          */
         private boolean isChildTypeSupported(final Type childType) {
             switch (this) {
                 case POLICY:
                 case ALL:
                 case EXACTLY_ONE:
                     switch (childType) {
                         case ASSERTION_PARAMETER_NODE:
                             return false;
                         default:
                             return true;
                     }
                 case POLICY_REFERENCE:
                     return false;
                 case ASSERTION:
                     switch (childType) {
                         case POLICY:
                         case POLICY_REFERENCE:
                         case ASSERTION_PARAMETER_NODE:
                             return true;
                         default:
                             return false;
                     }
                 case ASSERTION_PARAMETER_NODE:
                     switch (childType) {
                         case ASSERTION_PARAMETER_NODE:
                             return true;
                         default:
                             return false;
                     }
                 default:
                     throw LOGGER.logSevereException(new IllegalStateException(
                             LocalizationMessages.WSP_0060_POLICY_ELEMENT_TYPE_UNKNOWN(this)));
             }
         }
     }

     // comon model node attributes
     private LinkedList<ModelNode> children;
     private Collection<ModelNode> unmodifiableViewOnContent;
     private final ModelNode.Type type;
     private ModelNode parentNode;
     private PolicySourceModel parentModel;

     // attributes used only in 'POLICY_REFERENCE' model node
     private PolicyReferenceData referenceData;
     private PolicySourceModel referencedModel;

     // attibutes used only in 'ASSERTION' or 'ASSERTION_PARAMETER_NODE' model node
     private AssertionData nodeData;

     /**
      * The factory method creates and initializes the POLICY model node and sets it's parent model reference to point to
      * the model supplied as an input parameter. This method is intended to be used ONLY from {@link PolicySourceModel} during
      * the initialization of its own internal structures.
      *
      * @param model policy source model to be used as a parent model of the newly created {@link ModelNode}. Must not be {@code null}
      * @return POLICY model node with the parent model reference initialized to the model supplied as an input parameter
      * @throws IllegalArgumentException if the {@code model} input parameter is {@code null}
      */
     static ModelNode createRootPolicyNode(final PolicySourceModel model) throws IllegalArgumentException {
         if (model == null) {
             throw LOGGER.logSevereException(new IllegalArgumentException(LocalizationMessages.WSP_0039_POLICY_SRC_MODEL_INPUT_PARAMETER_MUST_NOT_BE_NULL()));
         }
         return new ModelNode(ModelNode.Type.POLICY, model);
     }

     private ModelNode(Type type, PolicySourceModel parentModel) {
         this.type = type;
         this.parentModel = parentModel;
         this.children = new LinkedList<ModelNode>();
         this.unmodifiableViewOnContent = Collections.unmodifiableCollection(this.children);
     }

     private ModelNode(Type type, PolicySourceModel parentModel, AssertionData data) {
         this(type, parentModel);

         this.nodeData = data;
     }

     private ModelNode(PolicySourceModel parentModel, PolicyReferenceData data) {
         this(Type.POLICY_REFERENCE, parentModel);

         this.referenceData = data;
     }

     private void checkCreateChildOperationSupportForType(final Type type) throws UnsupportedOperationException {
         if (!this.type.isChildTypeSupported(type)) {
             throw LOGGER.logSevereException(new UnsupportedOperationException(LocalizationMessages.WSP_0073_CREATE_CHILD_NODE_OPERATION_NOT_SUPPORTED(type, this.type)));
         }
     }

     /**
      * Factory method that creates new policy source model node as specified by a factory method name and input parameters.
      * Each node is created with respect to its enclosing policy source model.
      *
      * @return A new Policy node.
      */
     public ModelNode createChildPolicyNode() {
         checkCreateChildOperationSupportForType(Type.POLICY);

         final ModelNode node = new ModelNode(ModelNode.Type.POLICY, parentModel);
         this.addChild(node);

         return node;
     }

     /**
      * Factory method that creates new policy source model node as specified by a factory method name and input parameters.
      * Each node is created with respect to its enclosing policy source model.
      *
      * @return A new All node.
      */
     public ModelNode createChildAllNode() {
         checkCreateChildOperationSupportForType(Type.ALL);

         final ModelNode node = new ModelNode(ModelNode.Type.ALL, parentModel);
         this.addChild(node);

         return node;
     }

     /**
      * Factory method that creates new policy source model node as specified by a factory method name and input parameters.
      * Each node is created with respect to its enclosing policy source model.
      *
      * @return A new ExactlyOne node.
      */
     public ModelNode createChildExactlyOneNode() {
         checkCreateChildOperationSupportForType(Type.EXACTLY_ONE);

         final ModelNode node = new ModelNode(ModelNode.Type.EXACTLY_ONE, parentModel);
         this.addChild(node);

         return node;
     }

     /**
      * Factory method that creates new policy source model node as specified by a factory method name and input parameters.
      * Each node is created with respect to its enclosing policy source model.
      *
      * @return A new policy assertion node.
      */
     public ModelNode createChildAssertionNode() {
         checkCreateChildOperationSupportForType(Type.ASSERTION);

         final ModelNode node = new ModelNode(ModelNode.Type.ASSERTION, parentModel);
         this.addChild(node);

         return node;
     }

     /**
      * Factory method that creates new policy source model node as specified by a factory method name and input parameters.
      * Each node is created with respect to its enclosing policy source model.
      *
      * @param nodeData The policy assertion data.
      * @return A new policy assertion node.
      */
     public ModelNode createChildAssertionNode(final AssertionData nodeData) {
         checkCreateChildOperationSupportForType(Type.ASSERTION);

         final ModelNode node = new ModelNode(Type.ASSERTION, parentModel, nodeData);
         this.addChild(node);

         return node;
     }

     /**
      * Factory method that creates new policy source model node as specified by a factory method name and input parameters.
      * Each node is created with respect to its enclosing policy source model.
      *
      * @return A new assertion parameter node.
      */
     public ModelNode createChildAssertionParameterNode() {
         checkCreateChildOperationSupportForType(Type.ASSERTION_PARAMETER_NODE);

         final ModelNode node = new ModelNode(ModelNode.Type.ASSERTION_PARAMETER_NODE, parentModel);
         this.addChild(node);

         return node;
     }

     /**
      * Factory method that creates new policy source model node as specified by a factory method name and input parameters.
      * Each node is created with respect to its enclosing policy source model.
      *
      * @param nodeData The assertion parameter data.
      * @return A new assertion parameter node.
      */
     ModelNode createChildAssertionParameterNode(final AssertionData nodeData) {
         checkCreateChildOperationSupportForType(Type.ASSERTION_PARAMETER_NODE);

         final ModelNode node = new ModelNode(Type.ASSERTION_PARAMETER_NODE, parentModel, nodeData);
         this.addChild(node);

         return node;
     }

     /**
      * Factory method that creates new policy source model node as specified by a factory method name and input parameters.
      * Each node is created with respect to its enclosing policy source model.
      *
      * @param referenceData The PolicyReference data.
      * @return A new PolicyReference node.
      */
     ModelNode createChildPolicyReferenceNode(final PolicyReferenceData referenceData) {
         checkCreateChildOperationSupportForType(Type.POLICY_REFERENCE);

         final ModelNode node = new ModelNode(parentModel, referenceData);
         this.parentModel.addNewPolicyReference(node);
         this.addChild(node);

         return node;
     }

     Collection<ModelNode> getChildren() {
         return unmodifiableViewOnContent;
     }

     /**
      * Sets the parent model reference on the node and its children. The method may be invoked only on the root node
      * of the policy source model (or - in general - on a model node that dose not reference a parent node). Otherwise an
      * exception is thrown.
      *
      * @param model new parent policy source model to be set.
      * @throws IllegalAccessException in case this node references a parent node (i.e. is not a root node of the model).
      */
     void setParentModel(final PolicySourceModel model) throws IllegalAccessException {
         if (parentNode != null) {
             throw LOGGER.logSevereException(new IllegalAccessException(LocalizationMessages.WSP_0049_PARENT_MODEL_CAN_NOT_BE_CHANGED()));
         }

         this.updateParentModelReference(model);
     }

     /**
      * The method updates the parentModel reference on current model node instance and all of it's children
      *
      * @param model new policy source model reference.
      */
     private void updateParentModelReference(final PolicySourceModel model) {
         this.parentModel = model;

         for (ModelNode child : children) {
             child.updateParentModelReference(model);
         }
     }

     /**
      * Returns the parent policy source model that contains this model node.
      *
      * @return the parent policy source model
      */
     public PolicySourceModel getParentModel() {
         return parentModel;
     }

     /**
      * Returns the type of this policy source model node.
      *
      * @return actual type of this policy source model node
      */
     public ModelNode.Type getType() {
         return type;
     }

     /**
      * Returns the parent referenced by this policy source model node.
      *
      * @return current parent of this policy source model node or {@code null} if the node does not have a parent currently.
      */
     public ModelNode getParentNode() {
         return parentNode;
     }

     /**
      * Returns the data for this policy source model node (if any). The model node data are expected to be not {@code null} only in
      * case the type of this node is ASSERTION or ASSERTION_PARAMETER_NODE.
      *
      * @return the data of this policy source model node or {@code null} if the node does not have any data associated to it
      * attached.
      */
     public AssertionData getNodeData() {
         return nodeData;
     }

     /**
      * Returns the policy reference data for this policy source model node. The policy reference data are expected to be not {@code null} only in
      * case the type of this node is POLICY_REFERENCE.
      *
      * @return the policy reference data for this policy source model node or {@code null} if the node does not have any policy reference data
      * attached.
      */
     PolicyReferenceData getPolicyReferenceData() {
         return referenceData;
     }

     /**
      * The method may be used to set or replace assertion data set for this node. If there are assertion data set already,
      * those are replaced by a new reference and eventualy returned from the method.
      * <p/>
      * This method is supported only in case this model node instance's type is {@code ASSERTION} or {@code ASSERTION_PARAMETER_NODE}.
      * If used from other node types, an exception is thrown.
      *
      * @param newData new assertion data to be set.
      * @return old and replaced assertion data if any or {@code null} otherwise.
      *
      * @throws UnsupportedOperationException in case this method is called on nodes of type other than {@code ASSERTION}
      * or {@code ASSERTION_PARAMETER_NODE}
      */
     public AssertionData setOrReplaceNodeData(final AssertionData newData) {
         if (!isDomainSpecific()) {
             throw LOGGER.logSevereException(new UnsupportedOperationException(LocalizationMessages.WSP_0051_OPERATION_NOT_SUPPORTED_FOR_THIS_BUT_ASSERTION_RELATED_NODE_TYPE(type)));
         }

         final AssertionData oldData = this.nodeData;
         this.nodeData = newData;

         return oldData;
     }

     /**
      * The method specifies whether the model node instance represents assertion related node, it means whether its type
      * is 'ASSERTION' or 'ASSERTION_PARAMETER_NODE'. This is, for example, the way to determine whether the node supports
      * setting a {@link AssertionData} object via {@link #setOrReplaceNodeData(AssertionData)} method or not.
      *
      * @return {@code true} or {@code false} according to whether the node instance represents assertion related node or not.
      */
     boolean isDomainSpecific() {
         return type == Type.ASSERTION || type == Type.ASSERTION_PARAMETER_NODE;
     }

     /**
      * Appends the specified child node to the end of the children list of this node and sets it's parent to reference
      * this node.
      *
      * @param child node to be appended to the children list of this node.
      * @return {@code true} (as per the general contract of the {@code Collection.add} method).
      *
      * @throws NullPointerException if the specified node is {@code null}.
      * @throws IllegalArgumentException if child has a parent node set already to point to some node
      */
     private boolean addChild(final ModelNode child) {
         children.add(child);
         child.parentNode = this;

         return true;
     }

     void setReferencedModel(final PolicySourceModel model) {
         if (this.type != Type.POLICY_REFERENCE) {
             throw LOGGER.logSevereException(new UnsupportedOperationException(LocalizationMessages.WSP_0050_OPERATION_NOT_SUPPORTED_FOR_THIS_BUT_POLICY_REFERENCE_NODE_TYPE(type)));
         }

         referencedModel = model;
     }

     PolicySourceModel getReferencedModel() {
         return referencedModel;
     }

     /**
      * Returns the number of child policy source model nodes. If this model node contains
      * more than {@code Integer.MAX_VALUE} children, returns {@code Integer.MAX_VALUE}.
      *
      * @return the number of children of this node.
      */
     public int childrenSize() {
         return children.size();
     }

     /**
      * Returns true if the node has at least one child node.
      *
      * @return true if the node has at least one child node, false otherwise.
      */
     public boolean hasChildren() {
         return !children.isEmpty();
     }

     /**
      * Iterates through all child nodes.
      *
      * @return An iterator for the child nodes
      */
     public Iterator<ModelNode> iterator() {
         return children.iterator();
     }

     /**
      * An {@code Object.equals(Object obj)} method override. Method ignores the parent source model. It means that two
      * model nodes may be the same even if they belong to different models.
      * <p/>
      * If parent model comparison is desired, it must be accomplished separately. To perform that, the reference equality
      * test is sufficient ({@code nodeA.getParentModel() == nodeB.getParentModel()}), since all model nodes are created
      * for specific model instances.
      */
     @Override
     public boolean equals(final Object obj) {
         if (this == obj) {
             return true;
         }

         if (!(obj instanceof ModelNode)) {
             return false;
         }

         boolean result = true;
         final ModelNode that = (ModelNode) obj;

         result = result && this.type.equals(that.type);
         // result = result && ((this.parentNode == null) ? that.parentNode == null : this.parentNode.equals(that.parentNode));
         result = result && ((this.nodeData == null) ? that.nodeData == null : this.nodeData.equals(that.nodeData));
         result = result && ((this.children == null) ? that.children == null : this.children.equals(that.children));

         return result;
     }

     /**
      * An {@code Object.hashCode()} method override.
      */
     @Override
     public int hashCode() {
         int result = 17;

         result = 37 * result + this.type.hashCode();
         result = 37 * result + ((this.parentNode == null) ? 0 : this.parentNode.hashCode());
         result = 37 * result + ((this.nodeData == null) ? 0 : this.nodeData.hashCode());
         result = 37 * result + this.children.hashCode();

         return result;
     }

     /**
      * Returns a string representation of the object. In general, the <code>toString</code> method
      * returns a string that "textually represents" this object.
      *
      * @return  a string representation of the object.
      */
     @Override
     public String toString() {
         return toString(0, new StringBuffer()).toString();
     }

     /**
      * A helper method that appends indented string representation of this instance to the input string buffer.
      *
      * @param indentLevel indentation level to be used.
      * @param buffer buffer to be used for appending string representation of this instance
      * @return modified buffer containing new string representation of the instance
      */
     public StringBuffer toString(final int indentLevel, final StringBuffer buffer) {
         final String indent = PolicyUtils.Text.createIndent(indentLevel);
         final String innerIndent = PolicyUtils.Text.createIndent(indentLevel + 1);

         buffer.append(indent).append(type).append(" {").append(PolicyUtils.Text.NEW_LINE);
         if (type == Type.ASSERTION) {
             if (nodeData == null) {
                 buffer.append(innerIndent).append("no assertion data set");
             } else {
                 nodeData.toString(indentLevel + 1, buffer);
             }
             buffer.append(PolicyUtils.Text.NEW_LINE);
         } else if (type == Type.POLICY_REFERENCE) {
             if (referenceData == null) {
                 buffer.append(innerIndent).append("no policy reference data set");
             } else {
                 referenceData.toString(indentLevel + 1, buffer);
             }
             buffer.append(PolicyUtils.Text.NEW_LINE);
         } else if (type == Type.ASSERTION_PARAMETER_NODE) {
             if (nodeData == null) {
                 buffer.append(innerIndent).append("no parameter data set");
             }
             else {
                 nodeData.toString(indentLevel + 1, buffer);
             }
             buffer.append(PolicyUtils.Text.NEW_LINE);
         }

         if (children.size() > 0) {
             for (ModelNode child : children) {
                 child.toString(indentLevel + 1, buffer).append(PolicyUtils.Text.NEW_LINE);
             }
         } else {
             buffer.append(innerIndent).append("no child nodes").append(PolicyUtils.Text.NEW_LINE);
         }

         buffer.append(indent).append('}');
         return buffer;
     }

     @Override
     protected ModelNode clone() throws CloneNotSupportedException {
         final ModelNode clone = (ModelNode) super.clone();

         if (this.nodeData != null) {
             clone.nodeData = this.nodeData.clone();
         }

         // no need to clone PolicyReferenceData, since those are immutable

         if (this.referencedModel != null) {
             clone.referencedModel = this.referencedModel.clone();
         }


         clone.children = new LinkedList<ModelNode>();
         clone.unmodifiableViewOnContent = Collections.unmodifiableCollection(clone.children);

         for (ModelNode thisChild : this.children) {
             clone.addChild(thisChild.clone());
         }

         return clone;
     }

     PolicyReferenceData getReferenceData() {
         return referenceData;
     }
 }
	/*
	* Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code 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 General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package com.sun.xml.internal.ws.policy.sourcemodel;

	import com.sun.xml.internal.ws.policy.privateutil.LocalizationMessages;
	import com.sun.xml.internal.ws.policy.privateutil.PolicyLogger;
	import com.sun.xml.internal.ws.policy.privateutil.PolicyUtils;
	import com.sun.xml.internal.ws.policy.sourcemodel.wspolicy.XmlToken;

	import java.util.Collection;
	import java.util.Collections;
	import java.util.Iterator;
	import java.util.LinkedList;

	/**
	* The general representation of a single node within a {@link com.sun.xml.internal.ws.policy.sourcemodel.PolicySourceModel} instance.
	* The model node is created via factory methods of the {@link com.sun.xml.internal.ws.policy.sourcemodel.PolicySourceModel} instance.
	* It may also hold {@link com.sun.xml.internal.ws.policy.sourcemodel.AssertionData} instance in case its type is {@code ModelNode.Type.ASSERTION}.
	*
	* @author Marek Potociar
	*/
	public final class ModelNode implements Iterable<ModelNode>, Cloneable {
	private static final PolicyLogger LOGGER = PolicyLogger.getLogger(ModelNode.class);

	/**
	* Policy source model node type enumeration
	*/
	public static enum Type {
	POLICY(XmlToken.Policy),
	ALL(XmlToken.All),
	EXACTLY_ONE(XmlToken.ExactlyOne),
	POLICY_REFERENCE(XmlToken.PolicyReference),
	ASSERTION(XmlToken.UNKNOWN),
	ASSERTION_PARAMETER_NODE(XmlToken.UNKNOWN);

	private XmlToken token;

	Type(XmlToken token) {
	this.token = token;
	}

	public XmlToken getXmlToken() {
	return token;
	}

	/**
	* Method checks the PSM state machine if the creation of new child of given type is plausible for a node element
	* with type set to this type instance.
	*
	* @param childType The type.
	* @return True if the type is supported, false otherwise
	*/
	private boolean isChildTypeSupported(final Type childType) {
	switch (this) {
	case POLICY:
	case ALL:
	case EXACTLY_ONE:
	switch (childType) {
	case ASSERTION_PARAMETER_NODE:
	return false;
	default:
	return true;
	}
	case POLICY_REFERENCE:
	return false;
	case ASSERTION:
	switch (childType) {
	case POLICY:
	case POLICY_REFERENCE:
	case ASSERTION_PARAMETER_NODE:
	return true;
	default:
	return false;
	}
	case ASSERTION_PARAMETER_NODE:
	switch (childType) {
	case ASSERTION_PARAMETER_NODE:
	return true;
	default:
	return false;
	}
	default:
	throw LOGGER.logSevereException(new IllegalStateException(
	LocalizationMessages.WSP_0060_POLICY_ELEMENT_TYPE_UNKNOWN(this)));
	}
	}
	}

	// comon model node attributes
	private LinkedList<ModelNode> children;
	private Collection<ModelNode> unmodifiableViewOnContent;
	private final ModelNode.Type type;
	private ModelNode parentNode;
	private PolicySourceModel parentModel;

	// attributes used only in 'POLICY_REFERENCE' model node
	private PolicyReferenceData referenceData;
	private PolicySourceModel referencedModel;

	// attibutes used only in 'ASSERTION' or 'ASSERTION_PARAMETER_NODE' model node
	private AssertionData nodeData;

	/**
	* The factory method creates and initializes the POLICY model node and sets it's parent model reference to point to
	* the model supplied as an input parameter. This method is intended to be used ONLY from {@link PolicySourceModel} during
	* the initialization of its own internal structures.
	*
	* @param model policy source model to be used as a parent model of the newly created {@link ModelNode}. Must not be {@code null}
	* @return POLICY model node with the parent model reference initialized to the model supplied as an input parameter
	* @throws IllegalArgumentException if the {@code model} input parameter is {@code null}
	*/
	static ModelNode createRootPolicyNode(final PolicySourceModel model) throws IllegalArgumentException {
	if (model == null) {
	throw LOGGER.logSevereException(new IllegalArgumentException(LocalizationMessages.WSP_0039_POLICY_SRC_MODEL_INPUT_PARAMETER_MUST_NOT_BE_NULL()));
	}
	return new ModelNode(ModelNode.Type.POLICY, model);
	}

	private ModelNode(Type type, PolicySourceModel parentModel) {
	this.type = type;
	this.parentModel = parentModel;
	this.children = new LinkedList<ModelNode>();
	this.unmodifiableViewOnContent = Collections.unmodifiableCollection(this.children);
	}

	private ModelNode(Type type, PolicySourceModel parentModel, AssertionData data) {
	this(type, parentModel);

	this.nodeData = data;
	}

	private ModelNode(PolicySourceModel parentModel, PolicyReferenceData data) {
	this(Type.POLICY_REFERENCE, parentModel);

	this.referenceData = data;
	}

	private void checkCreateChildOperationSupportForType(final Type type) throws UnsupportedOperationException {
	if (!this.type.isChildTypeSupported(type)) {
	throw LOGGER.logSevereException(new UnsupportedOperationException(LocalizationMessages.WSP_0073_CREATE_CHILD_NODE_OPERATION_NOT_SUPPORTED(type, this.type)));
	}
	}

	/**
	* Factory method that creates new policy source model node as specified by a factory method name and input parameters.
	* Each node is created with respect to its enclosing policy source model.
	*
	* @return A new Policy node.
	*/
	public ModelNode createChildPolicyNode() {
	checkCreateChildOperationSupportForType(Type.POLICY);

	final ModelNode node = new ModelNode(ModelNode.Type.POLICY, parentModel);
	this.addChild(node);

	return node;
	}

	/**
	* Factory method that creates new policy source model node as specified by a factory method name and input parameters.
	* Each node is created with respect to its enclosing policy source model.
	*
	* @return A new All node.
	*/
	public ModelNode createChildAllNode() {
	checkCreateChildOperationSupportForType(Type.ALL);

	final ModelNode node = new ModelNode(ModelNode.Type.ALL, parentModel);
	this.addChild(node);

	return node;
	}

	/**
	* Factory method that creates new policy source model node as specified by a factory method name and input parameters.
	* Each node is created with respect to its enclosing policy source model.
	*
	* @return A new ExactlyOne node.
	*/
	public ModelNode createChildExactlyOneNode() {
	checkCreateChildOperationSupportForType(Type.EXACTLY_ONE);

	final ModelNode node = new ModelNode(ModelNode.Type.EXACTLY_ONE, parentModel);
	this.addChild(node);

	return node;
	}

	/**
	* Factory method that creates new policy source model node as specified by a factory method name and input parameters.
	* Each node is created with respect to its enclosing policy source model.
	*
	* @return A new policy assertion node.
	*/
	public ModelNode createChildAssertionNode() {
	checkCreateChildOperationSupportForType(Type.ASSERTION);

	final ModelNode node = new ModelNode(ModelNode.Type.ASSERTION, parentModel);
	this.addChild(node);

	return node;
	}

	/**
	* Factory method that creates new policy source model node as specified by a factory method name and input parameters.
	* Each node is created with respect to its enclosing policy source model.
	*
	* @param nodeData The policy assertion data.
	* @return A new policy assertion node.
	*/
	public ModelNode createChildAssertionNode(final AssertionData nodeData) {
	checkCreateChildOperationSupportForType(Type.ASSERTION);

	final ModelNode node = new ModelNode(Type.ASSERTION, parentModel, nodeData);
	this.addChild(node);

	return node;
	}

	/**
	* Factory method that creates new policy source model node as specified by a factory method name and input parameters.
	* Each node is created with respect to its enclosing policy source model.
	*
	* @return A new assertion parameter node.
	*/
	public ModelNode createChildAssertionParameterNode() {
	checkCreateChildOperationSupportForType(Type.ASSERTION_PARAMETER_NODE);

	final ModelNode node = new ModelNode(ModelNode.Type.ASSERTION_PARAMETER_NODE, parentModel);
	this.addChild(node);

	return node;
	}

	/**
	* Factory method that creates new policy source model node as specified by a factory method name and input parameters.
	* Each node is created with respect to its enclosing policy source model.
	*
	* @param nodeData The assertion parameter data.
	* @return A new assertion parameter node.
	*/
	ModelNode createChildAssertionParameterNode(final AssertionData nodeData) {
	checkCreateChildOperationSupportForType(Type.ASSERTION_PARAMETER_NODE);

	final ModelNode node = new ModelNode(Type.ASSERTION_PARAMETER_NODE, parentModel, nodeData);
	this.addChild(node);

	return node;
	}

	/**
	* Factory method that creates new policy source model node as specified by a factory method name and input parameters.
	* Each node is created with respect to its enclosing policy source model.
	*
	* @param referenceData The PolicyReference data.
	* @return A new PolicyReference node.
	*/
	ModelNode createChildPolicyReferenceNode(final PolicyReferenceData referenceData) {
	checkCreateChildOperationSupportForType(Type.POLICY_REFERENCE);

	final ModelNode node = new ModelNode(parentModel, referenceData);
	this.parentModel.addNewPolicyReference(node);
	this.addChild(node);

	return node;
	}

	Collection<ModelNode> getChildren() {
	return unmodifiableViewOnContent;
	}

	/**
	* Sets the parent model reference on the node and its children. The method may be invoked only on the root node
	* of the policy source model (or - in general - on a model node that dose not reference a parent node). Otherwise an
	* exception is thrown.
	*
	* @param model new parent policy source model to be set.
	* @throws IllegalAccessException in case this node references a parent node (i.e. is not a root node of the model).
	*/
	void setParentModel(final PolicySourceModel model) throws IllegalAccessException {
	if (parentNode != null) {
	throw LOGGER.logSevereException(new IllegalAccessException(LocalizationMessages.WSP_0049_PARENT_MODEL_CAN_NOT_BE_CHANGED()));
	}

	this.updateParentModelReference(model);
	}

	/**
	* The method updates the parentModel reference on current model node instance and all of it's children
	*
	* @param model new policy source model reference.
	*/
	private void updateParentModelReference(final PolicySourceModel model) {
	this.parentModel = model;

	for (ModelNode child : children) {
	child.updateParentModelReference(model);
	}
	}

	/**
	* Returns the parent policy source model that contains this model node.
	*
	* @return the parent policy source model
	*/
	public PolicySourceModel getParentModel() {
	return parentModel;
	}

	/**
	* Returns the type of this policy source model node.
	*
	* @return actual type of this policy source model node
	*/
	public ModelNode.Type getType() {
	return type;
	}

	/**
	* Returns the parent referenced by this policy source model node.
	*
	* @return current parent of this policy source model node or {@code null} if the node does not have a parent currently.
	*/
	public ModelNode getParentNode() {
	return parentNode;
	}

	/**
	* Returns the data for this policy source model node (if any). The model node data are expected to be not {@code null} only in
	* case the type of this node is ASSERTION or ASSERTION_PARAMETER_NODE.
	*
	* @return the data of this policy source model node or {@code null} if the node does not have any data associated to it
	* attached.
	*/
	public AssertionData getNodeData() {
	return nodeData;
	}

	/**
	* Returns the policy reference data for this policy source model node. The policy reference data are expected to be not {@code null} only in
	* case the type of this node is POLICY_REFERENCE.
	*
	* @return the policy reference data for this policy source model node or {@code null} if the node does not have any policy reference data
	* attached.
	*/
	PolicyReferenceData getPolicyReferenceData() {
	return referenceData;
	}

	/**
	* The method may be used to set or replace assertion data set for this node. If there are assertion data set already,
	* those are replaced by a new reference and eventualy returned from the method.
	* <p/>
	* This method is supported only in case this model node instance's type is {@code ASSERTION} or {@code ASSERTION_PARAMETER_NODE}.
	* If used from other node types, an exception is thrown.
	*
	* @param newData new assertion data to be set.
	* @return old and replaced assertion data if any or {@code null} otherwise.
	*
	* @throws UnsupportedOperationException in case this method is called on nodes of type other than {@code ASSERTION}
	* or {@code ASSERTION_PARAMETER_NODE}
	*/
	public AssertionData setOrReplaceNodeData(final AssertionData newData) {
	if (!isDomainSpecific()) {
	throw LOGGER.logSevereException(new UnsupportedOperationException(LocalizationMessages.WSP_0051_OPERATION_NOT_SUPPORTED_FOR_THIS_BUT_ASSERTION_RELATED_NODE_TYPE(type)));
	}

	final AssertionData oldData = this.nodeData;
	this.nodeData = newData;

	return oldData;
	}

	/**
	* The method specifies whether the model node instance represents assertion related node, it means whether its type
	* is 'ASSERTION' or 'ASSERTION_PARAMETER_NODE'. This is, for example, the way to determine whether the node supports
	* setting a {@link AssertionData} object via {@link #setOrReplaceNodeData(AssertionData)} method or not.
	*
	* @return {@code true} or {@code false} according to whether the node instance represents assertion related node or not.
	*/
	boolean isDomainSpecific() {
	return type == Type.ASSERTION \|\| type == Type.ASSERTION_PARAMETER_NODE;
	}

	/**
	* Appends the specified child node to the end of the children list of this node and sets it's parent to reference
	* this node.
	*
	* @param child node to be appended to the children list of this node.
	* @return {@code true} (as per the general contract of the {@code Collection.add} method).
	*
	* @throws NullPointerException if the specified node is {@code null}.
	* @throws IllegalArgumentException if child has a parent node set already to point to some node
	*/
	private boolean addChild(final ModelNode child) {
	children.add(child);
	child.parentNode = this;

	return true;
	}

	void setReferencedModel(final PolicySourceModel model) {
	if (this.type != Type.POLICY_REFERENCE) {
	throw LOGGER.logSevereException(new UnsupportedOperationException(LocalizationMessages.WSP_0050_OPERATION_NOT_SUPPORTED_FOR_THIS_BUT_POLICY_REFERENCE_NODE_TYPE(type)));
	}

	referencedModel = model;
	}

	PolicySourceModel getReferencedModel() {
	return referencedModel;
	}

	/**
	* Returns the number of child policy source model nodes. If this model node contains
	* more than {@code Integer.MAX_VALUE} children, returns {@code Integer.MAX_VALUE}.
	*
	* @return the number of children of this node.
	*/
	public int childrenSize() {
	return children.size();
	}

	/**
	* Returns true if the node has at least one child node.
	*
	* @return true if the node has at least one child node, false otherwise.
	*/
	public boolean hasChildren() {
	return !children.isEmpty();
	}

	/**
	* Iterates through all child nodes.
	*
	* @return An iterator for the child nodes
	*/
	public Iterator<ModelNode> iterator() {
	return children.iterator();
	}

	/**
	* An {@code Object.equals(Object obj)} method override. Method ignores the parent source model. It means that two
	* model nodes may be the same even if they belong to different models.
	* <p/>
	* If parent model comparison is desired, it must be accomplished separately. To perform that, the reference equality
	* test is sufficient ({@code nodeA.getParentModel() == nodeB.getParentModel()}), since all model nodes are created
	* for specific model instances.
	*/
	@Override
	public boolean equals(final Object obj) {
	if (this == obj) {
	return true;
	}

	if (!(obj instanceof ModelNode)) {
	return false;
	}

	boolean result = true;
	final ModelNode that = (ModelNode) obj;

	result = result && this.type.equals(that.type);
	// result = result && ((this.parentNode == null) ? that.parentNode == null : this.parentNode.equals(that.parentNode));
	result = result && ((this.nodeData == null) ? that.nodeData == null : this.nodeData.equals(that.nodeData));
	result = result && ((this.children == null) ? that.children == null : this.children.equals(that.children));

	return result;
	}

	/**
	* An {@code Object.hashCode()} method override.
	*/
	@Override
	public int hashCode() {
	int result = 17;

	result = 37 * result + this.type.hashCode();
	result = 37 * result + ((this.parentNode == null) ? 0 : this.parentNode.hashCode());
	result = 37 * result + ((this.nodeData == null) ? 0 : this.nodeData.hashCode());
	result = 37 * result + this.children.hashCode();

	return result;
	}

	/**
	* Returns a string representation of the object. In general, the <code>toString</code> method
	* returns a string that "textually represents" this object.
	*
	* @return a string representation of the object.
	*/
	@Override
	public String toString() {
	return toString(0, new StringBuffer()).toString();
	}

	/**
	* A helper method that appends indented string representation of this instance to the input string buffer.
	*
	* @param indentLevel indentation level to be used.
	* @param buffer buffer to be used for appending string representation of this instance
	* @return modified buffer containing new string representation of the instance
	*/
	public StringBuffer toString(final int indentLevel, final StringBuffer buffer) {
	final String indent = PolicyUtils.Text.createIndent(indentLevel);
	final String innerIndent = PolicyUtils.Text.createIndent(indentLevel + 1);

	buffer.append(indent).append(type).append(" {").append(PolicyUtils.Text.NEW_LINE);
	if (type == Type.ASSERTION) {
	if (nodeData == null) {
	buffer.append(innerIndent).append("no assertion data set");
	} else {
	nodeData.toString(indentLevel + 1, buffer);
	}
	buffer.append(PolicyUtils.Text.NEW_LINE);
	} else if (type == Type.POLICY_REFERENCE) {
	if (referenceData == null) {
	buffer.append(innerIndent).append("no policy reference data set");
	} else {
	referenceData.toString(indentLevel + 1, buffer);
	}
	buffer.append(PolicyUtils.Text.NEW_LINE);
	} else if (type == Type.ASSERTION_PARAMETER_NODE) {
	if (nodeData == null) {
	buffer.append(innerIndent).append("no parameter data set");
	}
	else {
	nodeData.toString(indentLevel + 1, buffer);
	}
	buffer.append(PolicyUtils.Text.NEW_LINE);
	}

	if (children.size() > 0) {
	for (ModelNode child : children) {
	child.toString(indentLevel + 1, buffer).append(PolicyUtils.Text.NEW_LINE);
	}
	} else {
	buffer.append(innerIndent).append("no child nodes").append(PolicyUtils.Text.NEW_LINE);
	}

	buffer.append(indent).append('}');
	return buffer;
	}

	@Override
	protected ModelNode clone() throws CloneNotSupportedException {
	final ModelNode clone = (ModelNode) super.clone();

	if (this.nodeData != null) {
	clone.nodeData = this.nodeData.clone();
	}

	// no need to clone PolicyReferenceData, since those are immutable

	if (this.referencedModel != null) {
	clone.referencedModel = this.referencedModel.clone();
	}


	clone.children = new LinkedList<ModelNode>();
	clone.unmodifiableViewOnContent = Collections.unmodifiableCollection(clone.children);

	for (ModelNode thisChild : this.children) {
	clone.addChild(thisChild.clone());
	}

	return clone;
	}

	PolicyReferenceData getReferenceData() {
	return referenceData;
	}
	}