This article demonstrates how to extract files from a PDF portfolio in Java using Spire.PDF for Java.
The input PDF:

import com.spire.pdf.PdfDocument;
import com.spire.pdf.attachments.PdfAttachment;
import java.io.*;
public class ReadPortfolio {
public static void main(String []args) throws IOException {
//Create a PdfDocument instance
PdfDocument pdf = new PdfDocument();
//Load the PDF file
pdf.loadFromFile("Portfolio.pdf");
//Loop through the attachments in the file
for(PdfAttachment attachment : (Iterable)pdf.getAttachments()){
//Extract files
String fileName = attachment.getFileName();
OutputStream fos = new FileOutputStream("extract/" + fileName);
fos.write(attachment.getData());
}
pdf.dispose();
}
}
Output:
