org.apache.cocoon.serialization.POIFSSerializer.java Source code

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Here is the source code for org.apache.cocoon.serialization.POIFSSerializer.java

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/*
 * Copyright 1999-2004 The Apache Software Foundation.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.cocoon.serialization;

import java.io.IOException;
import java.io.OutputStream;

import org.apache.cocoon.components.elementprocessor.ElementProcessor;
import org.apache.cocoon.components.elementprocessor.impl.poi.POIFSElementProcessor;

import org.apache.poi.poifs.filesystem.POIFSFileSystem;
import org.xml.sax.SAXException;

/**
 *  An extension of ElementProcessorSerializer with extensions for dealing with
 *  the POIFS filesystem This is an abstract class. Concrete extensions need to
 *  implement the following methods:
 *  <ul>
 *    <li> String getMimeType()</li>
 *    <li> void doLocalPreEndDocument()</li>
 *    <li> void doLocalPostEndDocument()</li>
 *    <li> ElementProcessorFactory getElementProcessorFactory()</li>
 *    </li>
 *  </ul>
 *
 * @author   Marc Johnson (marc_johnson27591@hotmail.com)
 * @author   Nicola Ken Barozzi (nicolaken@apache.org)
 * @version CVS $Id: POIFSSerializer.java 30932 2004-07-29 17:35:38Z vgritsenko $
 */
public abstract class POIFSSerializer extends ElementProcessorSerializer {
    private POIFSFileSystem _filesystem;

    /**
     *  Constructor
     */

    public POIFSSerializer() {
        super();
        _filesystem = new POIFSFileSystem();
    }

    /*
     *  ********** START implementation of ContentHandler **********
     */
    /**
     *  Receive notification of the end of a document.
     *
     *@exception  SAXException  if there is an error writing the document to the
     *      output stream
     */

    public void endDocument() throws SAXException {
        doLocalPreEndDocument();

        OutputStream stream = getOutputStream();

        if (stream != null) {
            try {
                _filesystem.writeFilesystem(stream);
            } catch (IOException e) {
                throw SAXExceptionFactory("could not process endDocument event", e);
            }
        } else {
            throw SAXExceptionFactory("no outputstream for writing the document!!");
        }
        doLocalPostEndDocument();
    }

    /**
     *  Provide access to the filesystem for extending classes
     *
     *@return    the filesystem
     */

    protected POIFSFileSystem getFilesystem() {
        return _filesystem;
    }

    /**
     *  Extending classes should do whatever they need to do prior to writing the
     *  filesystem out
     */

    protected abstract void doLocalPreEndDocument();

    /**
     *  Extending classes should do whatever they need to do after writing the
     *  filesystem out
     */

    protected abstract void doLocalPostEndDocument();

    /**
     *  perform pre-initialization on an element processor
     *
     *@param  processor         the element processor to be iniitialized
     *@exception  SAXException  on errors
     */

    protected void doPreInitialization(ElementProcessor processor) throws SAXException {
        try {
            ((POIFSElementProcessor) processor).setFilesystem(_filesystem);
        } catch (ClassCastException e) {
            throw SAXExceptionFactory("could not pre-initialize processor", e);
        }
    }

    /*
     *  **********  END  implementation of ContentHandler **********
     */
}
// end public abstract class POIFSSerializer