Java Requires Chilkat v11.7.0+

QR Code with a Text Caption

See more QR Code Examples

Demonstrates printing a line of text under a QR code, such as the order number or the address the code holds, so that a person can read it too. render.text turns the caption on and gives its value, which is printable ASCII and is drawn in a built-in font that needs no font files. The caption can go above or below the symbol, be aligned left, center or right, and be scaled. Chilkat2 Java

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

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.

        JsonObject json = new JsonObject();
        json.updateString("payload.text", "https://www.chilkatsoft.com/order/12345");
        json.updateInt("render.moduleSize", 6);

        // The caption.  It need not be the same as the text in the QR code.
        json.updateBool("render.text.enabled", true);
        json.updateString("render.text.value", "ORDER 12345");
        // position is "below" (the default) or "above".  alignment is "center" (the default), "left" or "right".
        json.updateString("render.text.position", "below");
        // Each dot of the caption's font is drawn this many pixels wide.
        json.updateInt("render.text.scale", 3);

        json.updateString("output.path", "qa_output/qr_caption.png");
        json.updateBool("output.overwrite", true);
        json.updateString("output.return", "none");

        Formats fmt = new Formats();
        JsonObject jsonOut = new JsonObject();
        try {
            fmt.qrCode("generate", json, jsonOut);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("caption: " + jsonOut.stringOf("measurements[0].text"));
        System.out.println("caption scale: " + jsonOut.intOf("measurements[0].textScale"));
        System.out.println("height added for the caption: " + jsonOut.intOf("measurements[0].textBandPx") + " pixels");
        System.out.println("image: " + jsonOut.intOf("measurements[0].canvasWidth") + " x " + jsonOut.intOf("measurements[0].canvasHeight") + " pixels");

        // The image written to qa_output/qr_caption.png:

        // 

        // Sample output:

        // caption: ORDER 12345
        // caption scale: 3
        // height added for the caption: 21 pixels
        // image: 222 x 243 pixels
    }
}