dev.ztgnrw.ExtractEmbeddedFiles.java Source code

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Here is the source code for dev.ztgnrw.ExtractEmbeddedFiles.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * 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
 * 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 dev.ztgnrw;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import org.apache.pdfbox.io.IOUtils;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDDocumentNameDictionary;
import org.apache.pdfbox.pdmodel.PDEmbeddedFilesNameTreeNode;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.common.PDNameTreeNode;
import org.apache.pdfbox.pdmodel.common.filespecification.PDComplexFileSpecification;
import org.apache.pdfbox.pdmodel.common.filespecification.PDEmbeddedFile;
import org.apache.pdfbox.pdmodel.interactive.annotation.PDAnnotation;
import org.apache.pdfbox.pdmodel.interactive.annotation.PDAnnotationFileAttachment;

/**
 * This is an example on how to extract all embedded files from a PDF document.
 *
 */
public final class ExtractEmbeddedFiles {

    private ExtractEmbeddedFiles() {
    }

    /**
     * This is the main method.
     *
     * @param args The command line arguments.
     *
     * @throws IOException If there is an error parsing the document.
     */
    public static void extractEmbeddedFiles(String file) throws IOException {

        PDDocument document = null;
        try {
            File pdfFile = new File(file);
            String filePath = pdfFile.getParent() + System.getProperty("file.separator");
            document = PDDocument.load(pdfFile);
            PDDocumentNameDictionary namesDictionary = new PDDocumentNameDictionary(document.getDocumentCatalog());
            PDEmbeddedFilesNameTreeNode efTree = namesDictionary.getEmbeddedFiles();
            if (efTree != null) {
                Map<String, PDComplexFileSpecification> names = efTree.getNames();
                if (names != null) {
                    extractFiles(names, filePath);
                } else {
                    List<PDNameTreeNode<PDComplexFileSpecification>> kids = efTree.getKids();
                    for (PDNameTreeNode<PDComplexFileSpecification> node : kids) {
                        names = node.getNames();
                        extractFiles(names, filePath);
                    }
                }
            }

            // extract files from annotations
            for (PDPage page : document.getPages()) {
                for (PDAnnotation annotation : page.getAnnotations()) {
                    if (annotation instanceof PDAnnotationFileAttachment) {
                        PDAnnotationFileAttachment annotationFileAttachment = (PDAnnotationFileAttachment) annotation;
                        PDComplexFileSpecification fileSpec = (PDComplexFileSpecification) annotationFileAttachment
                                .getFile();
                        PDEmbeddedFile embeddedFile = getEmbeddedFile(fileSpec);
                        extractFile(filePath, fileSpec.getFilename(), embeddedFile);
                    }
                }
            }

        } finally {
            if (document != null) {
                document.close();
            }
        }

    }

    private static void extractFiles(Map<String, PDComplexFileSpecification> names, String filePath)
            throws IOException {
        for (Entry<String, PDComplexFileSpecification> entry : names.entrySet()) {

            //entry.getKey returns the description so it was changed here to getFilename
            String filename = entry.getValue().getFilename();
            PDComplexFileSpecification fileSpec = entry.getValue();
            PDEmbeddedFile embeddedFile = getEmbeddedFile(fileSpec);
            extractFile(filePath, filename, embeddedFile);
        }
    }

    private static void extractFile(String filePath, String filename, PDEmbeddedFile embeddedFile)
            throws IOException {
        String embeddedFilename = filePath + filename;
        File file = new File(filePath + filename);
        System.out.println("Writing " + embeddedFilename);
        FileOutputStream fos = null;
        try {
            fos = new FileOutputStream(file);
            fos.write(embeddedFile.toByteArray());
        } finally {
            IOUtils.closeQuietly(fos);
        }
    }

    private static PDEmbeddedFile getEmbeddedFile(PDComplexFileSpecification fileSpec) {
        // search for the first available alternative of the embedded file
        PDEmbeddedFile embeddedFile = null;
        if (fileSpec != null) {
            embeddedFile = fileSpec.getEmbeddedFileUnicode();
            if (embeddedFile == null) {
                embeddedFile = fileSpec.getEmbeddedFileDos();
            }
            if (embeddedFile == null) {
                embeddedFile = fileSpec.getEmbeddedFileMac();
            }
            if (embeddedFile == null) {
                embeddedFile = fileSpec.getEmbeddedFileUnix();
            }
            if (embeddedFile == null) {
                embeddedFile = fileSpec.getEmbeddedFile();
            }
        }
        return embeddedFile;
    }

}