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Java Requires Chilkat v11.7.0+

Replace the Second (or Every) Occurrence of a Label in a PDF

See more PDF Text Replacement Examples

Demonstrates the "occurrence" member of a label entry. By default the first occurrence of a label, in reading order across the selected pages, is replaced; "occurrence" can be a number for the nth, or "all" for every occurrence. The invoice template has "Ref:" twice.

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

    //  The PDF used in this example is available at invoice_template.pdf

    CkPdf pdf = new CkPdf();
    success = pdf.LoadFile("qa_data/pdf/invoice_template.pdf");
    if (success == false) {
        System.out.println(pdf.lastErrorText());
        return;
        }

    CkJsonObject json = new CkJsonObject();
    CkJsonObject jsonOut = new CkJsonObject();

    //  This template's {{placeholders}} are not being filled here: "keep" leaves them as they are
    //  (the default, "error", would refuse to apply while a placeholder on the page has no value).
    json.UpdateString("unusedPlaceholders","keep");

    //  "Ref:" appears twice on the page (A-1 near the top, A-2 below the totals).
    //  The default replaces the first occurrence only.
    json.UpdateString("labels[0].label","Ref:");
    json.UpdateString("labels[0].value","B-7");
    success = pdf.TextReplace("check",json,jsonOut);
    if (success == false) {
        System.out.println(pdf.lastErrorText());
        return;
        }

    System.out.println("default: " + jsonOut.IntOf("replacements[0].count") + " occurrence replaced");

    //  The second occurrence only.
    json.UpdateString("labels[0].occurrence","2");
    success = pdf.TextReplace("check",json,jsonOut);
    if (success == false) {
        System.out.println(pdf.lastErrorText());
        return;
        }

    System.out.println("occurrence 2: " + jsonOut.IntOf("replacements[0].count") + " occurrence replaced");

    //  Every occurrence.
    json.UpdateString("labels[0].occurrence","all");
    success = pdf.TextReplace("apply",json,jsonOut);
    if (success == false) {
        System.out.println(pdf.lastErrorText());
        return;
        }

    System.out.println("occurrence all: " + jsonOut.IntOf("replacements[0].count") + " occurrences replaced");

    success = pdf.WriteFile("qa_output/invoice_refs.pdf");
    if (success == false) {
        System.out.println(pdf.lastErrorText());
        return;
        }

    //  Sample output:

    //  default: 1 occurrence replaced
    //  occurrence 2: 1 occurrence replaced
    //  occurrence all: 2 occurrences replaced
  }
}