استخراج پیوست ها از PDF از طریق Java

// Open document
Document pdfDocument = new Document(_dataDir+"input.pdf");
// Get particular embedded file
FileSpecification fileSpecification = pdfDocument.getEmbeddedFiles().get_Item(1);
// Get the file properties
System.out.printf("Name: - " + fileSpecification.getName());
System.out.printf("\nDescription: - " + fileSpecification.getDescription());
System.out.printf("\nMime Type: - " + fileSpecification.getMIMEType());
// Get attachment form PDF file
try {
    InputStream input = fileSpecification.getContents();
    File file = new File(fileSpecification.getName());
    // Create path for file from pdf
    file.getParentFile().mkdirs();
    // Create and extract file from pdf
    java.io.FileOutputStream output = 
        new java.io.FileOutputStream(
            fileSpecification.getName(), 
            true);
    byte[] buffer = new byte[4096];
    int n = 0;
    while (-1 != (n = input.read(buffer)))
        output.write(buffer, 0, n);
    // Close InputStream object
    input.close();
    output.close();
} 
catch (IOException e) {
    e.printStackTrace();
}
// Close Document object
pdfDocument.dispose();