poifsviewengine.java

Office格式转换代码

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2003 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" and
 *    "Apache POI" must not be used to endorse or promote products
 *    derived from this software without prior written permission. For
 *    written permission, please contact [e-mail].
 *
 * 5. Products derived from this software may not be called "Apache",
 *    "Apache POI", nor may "Apache" appear in their name, without
 *    prior written permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

package org.apache.poi.poifs.dev;

import java.io.*;

import java.util.*;

/**
 * This class contains methods used to inspect POIFSViewable objects
 *
 * @author Marc Johnson (mjohnson at apache dot org)
 */

public class POIFSViewEngine
{
    private static final String _EOL = System.getProperty("line.separator");

    /**
     * Inspect an object that may be viewable, and drill down if told
     * to
     *
     * @param viewable the object to be viewed
     * @param drilldown if true, and the object implements
     *                  POIFSViewable, inspect the objects' contents
     *                  (recursively)
     * @param indentLevel how far in to indent each string
     * @param indentString string to use for indenting
     *
     * @return a List of Strings holding the content
     */

    public static List inspectViewable(final Object viewable,
                                       final boolean drilldown,
                                       final int indentLevel,
                                       final String indentString)
    {
        List objects = new ArrayList();

        if (viewable instanceof POIFSViewable)
        {
            POIFSViewable inspected = ( POIFSViewable ) viewable;

            objects.add(indent(indentLevel, indentString,
                               inspected.getShortDescription()));
            if (drilldown)
            {
                if (inspected.preferArray())
                {
                    Object[] data = inspected.getViewableArray();

                    for (int j = 0; j < data.length; j++)
                    {
                        objects.addAll(inspectViewable(data[ j ], drilldown,
                                                       indentLevel + 1,
                                                       indentString));
                    }
                }
                else
                {
                    Iterator iter = inspected.getViewableIterator();

                    while (iter.hasNext())
                    {
                        objects.addAll(inspectViewable(iter.next(),
                                                       drilldown,
                                                       indentLevel + 1,
                                                       indentString));
                    }
                }
            }
        }
        else
        {
            objects.add(indent(indentLevel, indentString,
                               viewable.toString()));
        }
        return objects;
    }

    private static String indent(final int indentLevel,
                                 final String indentString, final String data)
    {
        StringBuffer finalBuffer  = new StringBuffer();
        StringBuffer indentPrefix = new StringBuffer();

        for (int j = 0; j < indentLevel; j++)
        {
            indentPrefix.append(indentString);
        }
        LineNumberReader reader =
            new LineNumberReader(new StringReader(data));

        try
        {
            String line = reader.readLine();

            while (line != null)
            {
                finalBuffer.append(indentPrefix).append(line).append(_EOL);
                line = reader.readLine();
            }
        }
        catch (IOException e)
        {
            finalBuffer.append(indentPrefix).append(e.getMessage())
                .append(_EOL);
        }
        return finalBuffer.toString();
    }
}   // end public class POIFSViewEngine