poi/examples/src/main/java/org/apache/poi/examples/hpsf/WriteAuthorAndTitle.java

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   this work for additional information regarding copyright ownership.
   The ASF licenses this file to You under the Apache License, Version 2.0
   (the "License"); you may not use this file except in compliance with
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   distributed under the License is distributed on an "AS IS" BASIS,
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package org.apache.poi.examples.hpsf;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import org.apache.poi.hpsf.HPSFRuntimeException;
import org.apache.poi.hpsf.MarkUnsupportedException;
import org.apache.poi.hpsf.NoPropertySetStreamException;
import org.apache.poi.hpsf.PropertySet;
import org.apache.poi.hpsf.PropertySetFactory;
import org.apache.poi.hpsf.Section;
import org.apache.poi.hpsf.SummaryInformation;
import org.apache.poi.hpsf.Variant;
import org.apache.poi.hpsf.WritingNotSupportedException;
import org.apache.poi.hpsf.wellknown.PropertyIDMap;
import org.apache.poi.poifs.eventfilesystem.POIFSReader;
import org.apache.poi.poifs.eventfilesystem.POIFSReaderEvent;
import org.apache.poi.poifs.filesystem.DirectoryEntry;
import org.apache.poi.poifs.filesystem.DocumentInputStream;
import org.apache.poi.poifs.filesystem.POIFSDocumentPath;
import org.apache.poi.poifs.filesystem.POIFSFileSystem;

/**
 * <p>This class is a sample application which shows how to write or modify the
 * author and title property of an OLE 2 document. This could be done in two
 * different ways:</p>
 *
 * <ul>
 *
 * <li><p>The first approach is to open the OLE 2 file as a POI filesystem
 * (see class {@link POIFSFileSystem}), read the summary information property
 * set (see classes {@link SummaryInformation} and {@link PropertySet}), write
 * the author and title properties into it and write the property set back into
 * the POI filesystem.</p></li>
 *
 * <li><p>The second approach does not modify the original POI filesystem, but
 * instead creates a new one. All documents from the original POIFS are copied
 * to the destination POIFS, except for the summary information stream. The
 * latter is modified by setting the author and title property before writing
 * it to the destination POIFS. It there are several summary information streams
 * in the original POIFS - e.g. in subordinate directories - they are modified
 * just the same.</p></li>
 *
 * </ul>
 *
 * <p>This sample application takes the second approach. It expects the name of
 * the existing POI filesystem's name as its first command-line parameter and
 * the name of the output POIFS as the second command-line argument. The
 * program then works as described above: It copies nearly all documents
 * unmodified from the input POI filesystem to the output POI filesystem. If it
 * encounters a summary information stream it reads its properties. Then it sets
 * the "author" and "title" properties to new values and writes the modified
 * summary information stream into the output file.</p>
 *
 * <p>Further explanations can be found in the HPSF HOW-TO.</p>
 */
@SuppressWarnings({"java:S106","java:S4823"})
public final class WriteAuthorAndTitle {
    private WriteAuthorAndTitle() {}

    /**
     * <p>Runs the example program.</p>
     *
     * @param args Command-line arguments. The first command-line argument must
     * be the name of a POI filesystem to read.
     * @throws IOException if any I/O exception occurs.
     */
    public static void main(final String[] args) throws IOException {
        /* Check whether we have exactly two command-line arguments. */
        if (args.length != 2) {
            System.err.println("Usage: WriteAuthorAndTitle originPOIFS destinationPOIFS");
            System.exit(1);
        }

        /* Read the names of the origin and destination POI filesystems. */
        final String srcName = args[0];
        final String dstName = args[1];

        /* Read the origin POIFS using the eventing API. The real work is done
         * in the class ModifySICopyTheRest which is registered here as a
         * POIFSReader. */
        try (POIFSFileSystem poifs = new POIFSFileSystem();
             OutputStream out = new FileOutputStream(dstName)) {
            final POIFSReader r = new POIFSReader();
            r.registerListener(e -> handleEvent(poifs, e));
            r.read(new File(srcName));

            /* Write the new POIFS to disk. */
            poifs.writeFilesystem(out);
        }
    }

    private interface InputStreamSupplier {
        InputStream get() throws IOException, WritingNotSupportedException;
    }

    /**
     * The method is called by POI's eventing API for each file in the origin POIFS.
     */
    private static void handleEvent(final POIFSFileSystem poiFs, final POIFSReaderEvent event) {
        // The following declarations are shortcuts for accessing the "event" object.
        final DocumentInputStream stream = event.getStream();

        try {
            final InputStreamSupplier isSup;

            // Find out whether the current document is a property set stream or not.
            if (PropertySet.isPropertySetStream(stream)) {
                // Yes, the current document is a property set stream. Let's create a PropertySet instance from it.
                PropertySet ps = PropertySetFactory.create(stream);

                // Now we know that we really have a property set.
                // The next step is to find out whether it is a summary information or not.
                if (ps.isSummaryInformation()) {
                    // Create a mutable property set as a copy of the original read-only property set.
                    ps = new PropertySet(ps);

                    // Retrieve the section containing the properties to modify.
                    // A summary information property set contains exactly one section.
                    final Section s = ps.getSections().get(0);

                    // Set the properties.
                    s.setProperty(PropertyIDMap.PID_AUTHOR, Variant.VT_LPSTR, "Rainer Klute");
                    s.setProperty(PropertyIDMap.PID_TITLE, Variant.VT_LPWSTR, "Test");
                }

                isSup = ps::toInputStream;
            } else {
                // No, the current document is not a property set stream. We copy it unmodified to the destination POIFS.
                isSup = event::getStream;
            }

            try (InputStream is = isSup.get()) {
                final POIFSDocumentPath path = event.getPath();

                // Ensures that the directory hierarchy for a document in a POI fileystem is in place.
                // Get the root directory. It does not have to be created since it always exists in a POIFS.
                DirectoryEntry de = poiFs.getRoot();

                for (int i=0; i<path.length(); i++) {
                    String subDir = path.getComponent(i);
                    de = (de.hasEntry(subDir)) ? (DirectoryEntry)de.getEntry(subDir) : de.createDirectory(subDir);
                }

                de.createDocument(event.getName(), is);
            }

        } catch (MarkUnsupportedException | WritingNotSupportedException | IOException | NoPropertySetStreamException ex) {
            // According to the definition of the processPOIFSReaderEvent method we cannot pass checked
            // exceptions to the caller.
            throw new HPSFRuntimeException("Could not read file " + event.getPath() + "/" + event.getName(), ex);
        }
    }
}