public  void collectionToSAX(Collection collection) throws SAXException 
{
        String ncollections;
        String nresources;
        String[] resources;
        String[] collections;
        try {
            ncollections = Integer.toString(collection.getChildCollectionCount());
            nresources = Integer.toString(collection.getResourceCount());
            attributes.clear();
            attributes.addAttribute("", RESOURCE_COUNT_ATTR,
                                    RESOURCE_COUNT_ATTR, "CDATA", nresources);
            attributes.addAttribute("", COLLECTION_COUNT_ATTR,
                                    COLLECTION_COUNT_ATTR, "CDATA", ncollections);
            collections = collection.listChildCollections();
            resources = collection.listResources();
            this.xmlConsumer.startDocument();
            this.xmlConsumer.startPrefixMapping(PREFIX, URI);
            this.xmlConsumer.startElement(URI, "collections",
                                          "collection:collections", attributes);
            // Print child collections
            for (int i = 0; i <  collections.length; i++) {
                attributes.clear();
                attributes.addAttribute("", "name", "name", "CDATA", collections[i]);
                this.xmlConsumer.startElement(URI, COLLECTION,
                                              QCOLLECTION, attributes);
                this.xmlConsumer.endElement(URI, COLLECTION, COLLECTION);
            }
            // Print child resources
            for (int i = 0; i <  resources.length; i++) {
                attributes.clear();
                attributes.addAttribute("", "name", "name", "CDATA", resources[i]);
                this.xmlConsumer.startElement(URI, RESOURCE,
                                              QRESOURCE, attributes);
                this.xmlConsumer.endElement(URI, RESOURCE, RESOURCE);
            }
            this.xmlConsumer.endElement(URI, "collections",
                                        "collection:collections");
            this.xmlConsumer.endPrefixMapping(PREFIX);
            this.xmlConsumer.endDocument();
        } catch (XMLDBException xde) {
            getLogger().warn("Collection listing failed: " + xde.getMessage());
            throw new SAXException("Collection listing failed: " + xde.getMessage());
        }
}

Output SAX events listing the collection.

 public  void configure(Configuration conf) throws ConfigurationException 
{
       this.driver = conf.getChild("driver").getValue();
       this.base = conf.getChild("base").getValue();
}

Configure the component. This class is expecting a configuration like the following one:

<driver>org.dbxml.client.xmldb.DatabaseImpl</driver>
<base>xmldb:dbxml:///db/</base>

NOTE: the driver can be any DB:XML compliant driver (although this component has been tested only with dbXML, and the trailing slash in the base tag is important!

 public  void generate() throws IOException, SAXException, ProcessingException 
{
        //String col = "/";
        //if (source.indexOf('/') != -1)
        col = source;
        try {
            collection = DatabaseManager.getCollection(base + col);
            if (collection == null) {
                throw new ResourceNotFoundException("Collection " + col +
                                                    " not found");
            }
            collectionToSAX(collection);
            collection.close();
        } catch (XMLDBException xde) {
            throw new ProcessingException("Unable to fetch content '"
                                          + source + "':" + xde.getMessage());
        } catch (NullPointerException npe) {
            getLogger().error("The XML:DB driver raised an exception");
            getLogger().error("probably the document was not found");
            throw new ProcessingException("Null pointer exception while " +
                                          "retrieving document : " + npe.getMessage());
        }
}

Parse the requested URI, connect to the XML:DB database and fetch the requested resource.

 public Serializable getKey() 
{
        return null;
}

The component isn't cached (yet)

 public SourceValidity getValidity() 
{
        return null;
}

The component isn't cached (yet)

 public  void initialize() throws Exception 
{
       try {
           Class c = Class.forName(driver);
           database = (Database)c.newInstance();
           DatabaseManager.registerDatabase(database);
       } catch (XMLDBException xde) {
           getLogger().error("Unable to connect to the XML:DB database");
           throw new ProcessingException("Unable to connect to the XML DB"
                                         + xde.getMessage());
       } catch (Exception e) {
           getLogger().error("There was a problem setting up the connection");
           getLogger().error("Make sure that your driver is available");
           throw new ProcessingException("Problem setting up the connection: "
                                         + e.getMessage());
       }
}

Initialize the component getting a database instance.

 public  void recycle() 
{
                       
        super.recycle();
        this.col = null;
        this.collection = null;
}

Recycle the component, keep only the configuration variables and the database instance for reuse.

 public  void setup(SourceResolver resolver,
    Map objectModel,
    String src,
    Parameters par) throws IOException, SAXException, ProcessingException 
{
        Deprecation.logger.warn("The XMLDBCollectionGenerator is deprecated. Use the XML:DB pseudo protocol instead");
        super.setup(resolver, objectModel, src, par);
}