Source code: com/aendvari/cerberus/component/descriptor/parser/InstanceParser.java

   /*
    * InstanceParser.java
    *
    * Copyright (c) 2001, 2002 Aendvari, Ltd. All Rights Reserved.
    *
    * See the file LICENSE for terms of use.
    *
    */
   
  package com.aendvari.cerberus.component.descriptor.parser;
  
  import java.io.InputStream;
  import java.io.IOException;
  
  import java.util.ArrayList;
  import java.util.Collection;
  
  import com.aendvari.common.model.*;
  import com.aendvari.common.model.osm.*;
  
  import com.aendvari.cerberus.component.descriptor.*;
  
  /**
   * <p>Constructs a {@link ComponentInstance} from the content of a {@link ModelNode}.</p>
   *
   * <p>The {@link ModelNode} contains a single component instance.</p>
   *
   * <p>This class only reads the content of the {@link ModelNode}, it does not attempt to verify the data.</p>
   *
   * @author  Trevor Milne
   *
   */
  
  public class InstanceParser extends DescriptorParser
  {
    /* Constants. */
  
  
    /** Constants for descriptor element names. */
    private interface NodeNames
    {
      public static String Component      = "component";
  
      public static String Name        = "name";
      public static String Definition      = "definition";
  
      public static String Attribute      = "attribute";
      public static String Constant      = "constant";
      public static String Value        = "value";
  
      public static String Message      = "message";
      public static String Topic        = "topic";
      public static String Map        = "map";
    }
  
  
    /* Constructors. */
  
  
    /**
     * Constructs a <code>InstanceParser</code> instance.
     *
     */
  
    public InstanceParser()
    {
    }
  
  
    /* Parsing. */
  
  
    /**
     * Parses an attribute of a component instance.
     *
     * @param    objectNode          The {@link ModelNode} containing the attribute.
     *
     * @return                  A {@link ComponentAttribute} containing the attribute information.
     *
     */
  
    private ComponentAttribute parseAttribute(ModelNode objectNode)
    {
      // create a attribute
      ComponentAttribute attribute = new ComponentAttribute();
  
      ModelNode node = objectNode.getFirstChild();
  
      while (node != null)
      {
        String nodeName = node.getNodeName();
  
        // process node types
        if (nodeName.equals(NodeNames.Name))
        {
          attribute.setName(node.getNodeValue());
        }
        else
        if (nodeName.equals(NodeNames.Value))
       {
         MultiPartValue value = attribute.getValue();
         parseMultiPartValue(node, value);
       }
 
       // get next child node
       node = node.getNextSibling();
     }
 
     return attribute;
   }
 
   /**
    * Parses a message of a component instance.
    *
    * @param    objectNode          The {@link ModelNode} containing the message.
    *
    * @return                  A {@link ComponentMessage} containing the message information.
    *
    */
 
   private ComponentMessage parseMessage(ModelNode objectNode)
   {
     // create a message
     ComponentMessage message = new ComponentMessage();
 
     ModelNode node = objectNode.getFirstChild();
 
     while (node != null)
     {
       String nodeName = node.getNodeName();
 
       // process node types
       if (nodeName.equals(NodeNames.Name))
       {
         message.setName(node.getNodeValue());
       }
       else
       if (nodeName.equals(NodeNames.Topic))
       {
         MultiPartValue topic = message.getTopic();
         parseMultiPartValue(node, topic);
       }
       else
       if (nodeName.equals(NodeNames.Map))
       {
         // place mapped message name as 'topic' of message
         message.setMapped(true);
 
         MultiPartValue name = message.getTopic();
         name.addLiteral(node.getNodeValue());
       }
 
       // get next child node
       node = node.getNextSibling();
     }
 
     return message;
   }
 
   /**
    * Parses the given {@link ModelNode} containing a component instance. The {@link ModelNode}
    * must be the <instance> element.
    *
    * @param    instanceNode          A {@link ModelNode} containing a component instance.
    *
    * @return                    A {@link ComponentInstance} containing the information in the node.
    *
    */
 
   public ComponentInstance parse(ModelNode instanceNode)
   {
     ComponentInstance instance = new ComponentInstance();
 
     ModelNode node = instanceNode.getFirstChild();
 
     while (node != null)
     {
       String nodeName = node.getNodeName();
 
       // process node types
       if (nodeName.equals(NodeNames.Name))
       {
         instance.setName(node.getNodeValue());
       }
       else
       if (nodeName.equals(NodeNames.Definition))
       {
         instance.setDefinition(node.getNodeValue());
       }
       else
       if (nodeName.equals(NodeNames.Message))
       {
         instance.addMessage(parseMessage(node));
       }
       else
       if (nodeName.equals(NodeNames.Attribute))
       {
         instance.addAttribute(parseAttribute(node));
       }
 
       // get next child node
       node = node.getNextSibling();
     }
 
     return instance;
   }
 
   /**
    * Parses the content of the given <code>InputStream</code> as a component instance.
    *
    * @param    inputStream            The <code>InputStream</code> containing the component instance.
    *
    * @return                    A {@link ComponentInstance} containing the information in the stream.
    *
    * @exception  ParserException          The input stream could not be parsed.
    *
    */
 
   public ComponentInstance parse(InputStream inputStream)
     throws ParserException
   {
     ModelTree modelTree = new OsmModelTree();
 
     try
     {
       // read the content of the stream
       modelTree.loadFromStream(inputStream);
     }
     catch (ModelParserException exception)
     {
       throw new ParserException(exception);
     }
 
     // parse the tree, ignore the "OsmRoot" node
     ModelNode node = modelTree.getRootNode().getFirstChild();
     ComponentInstance instance = parse(node);
 
     return instance;
   }
 }