Java

PDF Update or Add XML Metadata

Demonstrates how to add or update the XML metadata stored in a PDF.

Note: This example requires Chilkat v10.1.0 or later.

Java

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[])
  {
    boolean success = false;

    // This requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    CkPdf pdf = new CkPdf();

    // Load a PDF file.
    // If the PDF file already has metadata, we'll update it.
    // Otherwise this example adds the metadata.
    success = pdf.LoadFile("qa_data/pdf/blank_with_metadata.pdf");
    if (success == false) {
        System.out.println(pdf.lastErrorText());
        return;
        }

    CkXml xml = new CkXml();
    CkStringBuilder sbExisting = new CkStringBuilder();

    boolean hasMetadata = pdf.GetMetadata(sbExisting);
    if (hasMetadata == true) {
        xml.LoadSb(sbExisting,true);
        }
    else {

        // Otherwise create the bare minimum XMP metadata.
        xml.put_Tag("x:xmpmeta");
        xml.AddAttribute("xmlns:x","adobe:ns:meta/");
        xml.AddAttribute("x:xmptk","Adobe XMP Core 9.1-c001 79.675d0f7, 2023/06/11-19:21:16 ");
        xml.UpdateAttrAt("rdf:RDF",true,"xmlns:rdf","http://www.w3.org/1999/02/22-rdf-syntax-ns#");
        xml.UpdateAttrAt("rdf:RDF|rdf:Description",true,"rdf:about","");
        xml.UpdateAttrAt("rdf:RDF|rdf:Description",true,"xmlns:xmp","http://ns.adobe.com/xap/1.0/");
        xml.UpdateAttrAt("rdf:RDF|rdf:Description",true,"xmlns:dc","http://purl.org/dc/elements/1.1/");
        xml.UpdateAttrAt("rdf:RDF|rdf:Description",true,"xmlns:xmpMM","http://ns.adobe.com/xap/1.0/mm/");
        xml.UpdateAttrAt("rdf:RDF|rdf:Description",true,"xmlns:pdf","http://ns.adobe.com/pdf/1.3/");
        xml.UpdateAttrAt("rdf:RDF|rdf:Description",true,"xmlns:xmpRights","http://ns.adobe.com/xap/1.0/rights/");

        CkDateTime dt = new CkDateTime();
        dt.SetFromCurrentSystemTime();
        String ts = dt.getAsTimestamp(true);

        xml.UpdateChildContent("rdf:RDF|rdf:Description|xmp:ModifyDate",ts);
        xml.UpdateChildContent("rdf:RDF|rdf:Description|xmp:CreateDate",ts);
        xml.UpdateChildContent("rdf:RDF|rdf:Description|xmp:MetadataDate",ts);

        xml.UpdateChildContent("rdf:RDF|rdf:Description|xmp:CreatorTool","My Custom Application");
        xml.UpdateChildContent("rdf:RDF|rdf:Description|dc:format","application/pdf");

        CkStringBuilder sbDocId = new CkStringBuilder();
        sbDocId.Append("uuid:");
        sbDocId.AppendUuid(true);
        xml.UpdateChildContent("rdf:RDF|rdf:Description|xmpMM:DocumentID",sbDocId.getAsString());

        CkStringBuilder sbInstanceId = new CkStringBuilder();
        sbInstanceId.Append("uuid:");
        sbInstanceId.AppendUuid(true);
        xml.UpdateChildContent("rdf:RDF|rdf:Description|xmpMM:InstanceID",sbInstanceId.getAsString());

        }

    // Add our custom metadata tags to either the existing XML metdata, or the newly created metadata.
    xml.UpdateAttrAt("rdf:RDF|rdf:Description",true,"xmlns:zf","urn:ferd:pdfa:CrossIndustryDocument:invoice:1p0#");
    xml.UpdateAttrAt("rdf:RDF|rdf:Description",true,"rdf:about"," ");
    xml.UpdateChildContent("rdf:RDF|rdf:Description|zf:ConformanceLevel","BASIC");
    xml.UpdateChildContent("rdf:RDF|rdf:Description|zf:DocumentFileName","ZZZZZZ-invoice.xml");
    xml.UpdateChildContent("rdf:RDF|rdf:Description|zf:DocumentType","INVOICE");
    xml.UpdateChildContent("rdf:RDF|rdf:Description|zf:Version","1.0");

    // Create a new PDF with the updated metadata.
    CkStringBuilder sb = new CkStringBuilder();
    xml.GetXmlSb(sb);
    success = pdf.UpdateMetadata(sb,"c:/temp/qa_output/out.pdf");
    if (success == true) {
        System.out.println("Success");
        }
    else {
        System.out.println(pdf.lastErrorText());
        }

    // To see the metadata in Adobe Acrobat DC,
    // 1) Open the PDF.
    // 2) CTRL-D to show the Document Properties dialog.
    // 3) In the dialog, click on the "Additional Metadata" button.
    // 4) In the Additional Data dialog, click on "Advanced"
    // 5) Expand the namespace tree for the metadata you added.

    System.out.println("OK");
  }
}