(Java) Extract Embedded Files from PDF

Demonstrates how to get information about the embedded files (if any) contained within a PDF, and shows how to extract each file.

Note: This example requires Chilkat v9.5.0.95 or greater.

Chilkat Java Downloads Java Libs for Windows, MacOS, Linux, Alpine Linux, Solaris Java Libs for Android

import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    CkPdf pdf = new CkPdf();

    boolean success = pdf.LoadFile("qa_data/pdf/embedded_files/my_embedded_files_test.pdf");
    if (success == false) {
        System.out.println(pdf.lastErrorText());
        return;
        }

    // Note: The embedded file functionality was added in Chilkat v9.5.0.95

    // How many embedded files exist within the opened PDF?
    int numFiles = pdf.get_NumEmbeddedFiles();
    System.out.println("Number of embedded files: " + numFiles);

    CkJsonObject json = new CkJsonObject();
    json.put_EmitCompact(false);

    CkBinData bd = new CkBinData();

    // Get information about each file, and extract each to the filesystem.
    int i = 0;
    while (i < numFiles) {

        success = pdf.GetEmbeddedFileInfo(i,json);
        if (success == false) {
            System.out.println(pdf.lastErrorText());
            return;
            }

        System.out.println(json.emit());

        // Get the filename from the JSON.
        String filename = "someFile.dat";

        // The filename SHOULD always be present..
        if (json.HasMember("filename") == true) {
            filename = json.stringOf("filename");
            }

        // Get the file data.
        success = pdf.GetEmbeddedFileBd(i,bd);
        if (success == false) {
            System.out.println(pdf.lastErrorText());
            return;
            }

        // Save the contents of the bd to the filename (in the current working directory) in the filesystem.
        success = bd.WriteFile(filename);
        if (success == false) {
            System.out.println("Failed to write output file.");
            }

        i = i+1;
        }

    // Sample output for the above code:

    // Number of embedded files: 3
    // {
    //   "filename": "employees.json",
    //   "desc": "JSON",
    //   "subType": "application/json",
    //   "size": 159,
    //   "creationDate": "D:20230715170506-05'00'",
    //   "modDate": "D:20160207153838-05'00'"
    // }
    // 
    // {
    //   "filename": "rsaPubKey.pem",
    //   "desc": "RSA Public Key PEM",
    //   "size": 451,
    //   "creationDate": "D:20230715170546-05'00'",
    //   "modDate": "D:20150724133153-05'00'"
    // }
    // 
    // {
    //   "filename": "starfish.jpg",
    //   "desc": "Starfish JPG",
    //   "subType": "image/jpeg",
    //   "size": 6229,
    //   "creationDate": "D:20230715170356-05'00'",
    //   "modDate": "D:20080529103055-05'00'"
    // }
  }
}