poi-examples/src/main/java/org/apache/poi/examples/hssf/usermodel/EmbeddedObjects.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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       http://www.apache.org/licenses/LICENSE-2.0

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   See the License for the specific language governing permissions and
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package org.apache.poi.examples.hssf.usermodel;

import java.io.Closeable;
import java.io.FileInputStream;

import org.apache.poi.hslf.usermodel.HSLFSlideShow;
import org.apache.poi.hssf.usermodel.HSSFObjectData;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hwpf.HWPFDocument;
import org.apache.poi.poifs.filesystem.DirectoryNode;
import org.apache.poi.poifs.filesystem.Entry;
import org.apache.poi.poifs.filesystem.POIFSFileSystem;

/**
 * Demonstrates how you can extract embedded data from a .xls file
 */
@SuppressWarnings({"java:S106","java:S4823","java:S1192"})
public final class EmbeddedObjects {
    private EmbeddedObjects() {}

    @SuppressWarnings("unused")
    public static void main(String[] args) throws Exception {
        try (
            FileInputStream fis = new FileInputStream(args[0]);
            POIFSFileSystem fs = new POIFSFileSystem(fis);
            HSSFWorkbook workbook = new HSSFWorkbook(fs)
        ) {
            for (HSSFObjectData obj : workbook.getAllEmbeddedObjects()) {
                //the OLE2 Class Name of the object
                String oleName = obj.getOLE2ClassName();
                DirectoryNode dn = (obj.hasDirectoryEntry()) ? (DirectoryNode) obj.getDirectory() : null;
                Closeable document = null;
                switch (oleName) {
                    case "Worksheet":
                        document = new HSSFWorkbook(dn, fs, false);
                        break;
                    case "Document":
                        document = new HWPFDocument(dn);
                        break;
                    case "Presentation":
                        document = new HSLFSlideShow(dn);
                        break;
                    default:
                        if (dn != null) {
                            // The DirectoryEntry is a DocumentNode. Examine its entries to find out what it is
                            for (Entry entry : dn) {
                                String name = entry.getName();
                            }
                        } else {
                            // There is no DirectoryEntry
                            // Recover the object's data from the HSSFObjectData instance.
                            byte[] objectData = obj.getObjectData();
                        }
                        break;
                }
                if (document != null) {
                    document.close();
                }
            }
        }
    }
}