Java Requires Chilkat v11.7.0+

Generate a QR Code PNG in Memory

See more QR Code Examples

Demonstrates getting a QR code image without writing a file. With no output options the result is a PNG returned as base64 in outputs[0].base64 of the response. The example decodes it into a BinData, which holds the bytes of the PNG to send in an HTTP response, store in a database, attach to an email, or save. 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.

    CkJsonObject json = new CkJsonObject();
    json.UpdateString("payload.text","https://www.chilkatsoft.com/");
    json.UpdateInt("render.moduleSize",6);

    CkFormats fmt = new CkFormats();
    CkJsonObject jsonOut = new CkJsonObject();
    success = fmt.QrCode("generate",json,jsonOut);
    if (success == false) {
        System.out.println(fmt.lastErrorText());
        return;
        }

    System.out.println("format: " + jsonOut.stringOf("outputs[0].format"));
    System.out.println("MIME type: " + jsonOut.stringOf("outputs[0].mimeType"));
    System.out.println("image: " + jsonOut.IntOf("outputs[0].width") + " x " + jsonOut.IntOf("outputs[0].height") + " pixels");

    //  outputs[0].base64 is the PNG file, base64 encoded.
    CkBinData bdPng = new CkBinData();
    success = bdPng.AppendEncoded(jsonOut.stringOf("outputs[0].base64"),"base64");
    if (success == false) {
        System.out.println(bdPng.lastErrorText());
        return;
        }

    System.out.println("PNG bytes: " + bdPng.get_NumBytes());

    //  The BinData holds the image.  Here it is simply saved.
    success = bdPng.WriteFile("qa_output/qr_in_memory.png");
    if (success == false) {
        System.out.println(bdPng.lastErrorText());
        return;
        }

    //  The PNG held in bdPng:

    //  

    //  Sample output:

    //  format: png
    //  MIME type: image/png
    //  image: 222 x 222 pixels
    //  PNG bytes: 877
  }
}