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.

Chilkat2 Java

import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.DateTime;
import com.chilkatsoft.chilkat2.Pdf;
import com.chilkatsoft.chilkat2.StringBuilder;
import com.chilkatsoft.chilkat2.Xml;

public class ChilkatExample {

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

        Pdf pdf = new Pdf();

        // Load a PDF file.
        // If the PDF file already has metadata, we'll update it.
        // Otherwise this example adds the metadata.
        try {
            pdf.loadFile("qa_data/pdf/blank_with_metadata.pdf");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        Xml xml = new Xml();
        StringBuilder sbExisting = new StringBuilder();

        boolean hasMetadata;
        try {
            pdf.getMetadata(sbExisting);
            hasMetadata = true;
        } catch (ChilkatException e) {
            hasMetadata = false;
        }
        if (hasMetadata) {
            xml.loadSb(sbExisting, true);
        } else {
            // Otherwise create the bare minimum XMP metadata.
            xml.setTag("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/");

            DateTime dt = new DateTime();
            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");

            StringBuilder sbDocId = new StringBuilder();
            sbDocId.append("uuid:");
            sbDocId.appendUuid(true);
            xml.updateChildContent("rdf:RDF|rdf:Description|xmpMM:DocumentID", sbDocId.getAsString());

            StringBuilder sbInstanceId = new StringBuilder();
            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.
        StringBuilder sb = new StringBuilder();
        xml.getXmlSb(sb);
        try {
            pdf.updateMetadata(sb, "c:/temp/qa_output/out.pdf");
            System.out.println("Success");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
        }

        // 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");
    }
}