Java Requires Chilkat v11.7.0+

PDF Placeholders Without a Value: Error, Blank or Keep

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Demonstrates the "unusedPlaceholders" option, which decides what happens to a placeholder found on the page that has no value in "placeholders": "error" (the default) makes it a problem with the reason unusedPlaceholder, so nothing is applied; "blank" replaces it with nothing; "keep" leaves it on the page as it is. Chilkat2 Java

import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.JsonObject;
import com.chilkatsoft.chilkat2.Pdf;

public class ChilkatExample {

    public static void main(String[] args) {
        // 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

        Pdf pdf = new Pdf();
        try {
            pdf.loadFile("qa_data/pdf/invoice_template.pdf");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Values for every placeholder except {{po}} (the purchase order number, which this customer has none of).
        JsonObject json = new JsonObject();
        json.updateString("placeholders.customer", "Acme Corp");
        json.updateString("placeholders.date", "2026-10-18");
        json.updateString("placeholders.qty1", "2");
        json.updateString("placeholders.desc1", "Cordless drill, 18 V");
        json.updateString("placeholders.price1", "$460.00");
        json.updateString("placeholders.amount1", "$920.00");
        json.updateString("placeholders.qty2", "6");
        json.updateString("placeholders.desc2", "Galvanized hinge, 4 inch");
        json.updateString("placeholders.price2", "$12.50");
        json.updateString("placeholders.amount2", "$75.00");
        json.updateString("placeholders.subtotal", "$995.00");
        json.updateString("placeholders.taxRate", "7.35%");
        json.updateString("placeholders.tax", "$73.13");
        json.updateString("placeholders.total", "$1,068.13");

        JsonObject jsonOut = new JsonObject();

        // The default, "error": the unfilled {{po}} is a problem and nothing would be applied.
        try {
            pdf.textReplace("check", json, jsonOut);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("error (default): ok = " + jsonOut.boolOf("ok") + ", problem: " + jsonOut.stringOf("problems[0].field") + " " + jsonOut.stringOf("problems[0].reason"));

        // "keep": {{po}} stays on the page, literally.
        json.updateString("unusedPlaceholders", "keep");
        try {
            pdf.textReplace("check", json, jsonOut);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("keep: ok = " + jsonOut.boolOf("ok"));

        // "blank": {{po}} is replaced by nothing, leaving "PO Number:" with an empty value.
        json.updateString("unusedPlaceholders", "blank");
        try {
            pdf.textReplace("apply", json, jsonOut);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("blank: applied = " + jsonOut.boolOf("applied"));

        try {
            pdf.writeFile("qa_output/invoice_no_po.pdf");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Sample output:

        // error (default): ok = false, problem: po unusedPlaceholder
        // keep: ok = true
        // blank: applied = true
    }
}