Simple utility class to create QR Code as Bitmap on Android using ZXing library

QRCodeUtil.java

import android.graphics.Bitmap;
import android.graphics.Color;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;

public class QRCodeUtil {

    private QRCodeUtil() {}

    public static Bitmap encodeAsBitmap(String source, int width, int height) {
        BitMatrix result;

        try {
            result = new MultiFormatWriter().encode(source, BarcodeFormat.QR_CODE, width, height, null);
        } catch (IllegalArgumentException | WriterException e) {
            // Unsupported format
            return null;
        }

        final int w = result.getWidth();
        final int h = result.getHeight();
        final int[] pixels = new int[w * h];

        for (int y = 0; y < h; y++) {
            final int offset = y * w;
            for (int x = 0; x < w; x++) {
                pixels[offset + x] = result.get(x, y) ? Color.BLACK : Color.WHITE;
            }
        }

        final Bitmap bitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
        bitmap.setPixels(pixels, 0, width, 0, 0, w, h);

        return bitmap;
    }

}

Thank you!

Kotlin version

import android.graphics.Bitmap
import android.graphics.Color
import com.google.zxing.BarcodeFormat
import com.google.zxing.MultiFormatWriter
import com.google.zxing.common.BitMatrix

fun encodeAsBitmap(source: String, width: Int, height: Int):Bitmap? {

    val result: BitMatrix = try {
        MultiFormatWriter().encode(source, BarcodeFormat.QR_CODE, width, height, null)
    } catch (e: Exception) {
        return null
    }

    val w = result.width
    val h = result.height
    val pixels = IntArray(w * h)

    for (y in 0 until h) {
        val offset = y * w
        for (x in 0 until w) {
            pixels[offset + x] = if (result[x, y]) Color.BLACK else Color.WHITE
        }
    }

    val bitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888)
    bitmap.setPixels(pixels, 0, width, 0, 0, w, h)

    return bitmap
}

Do this to minimize the margins:

// Use a hintmap to minimize margins
HashMap hintMap = new HashMap();
hintMap.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.Q);
hintMap.put(EncodeHintType.MARGIN, 0);

result = new MultiFormatWriter().encode(source, BarcodeFormat.QR_CODE, width, height, hintMap);

Note that there will still be a white margin, since if you have a black background the QR code would be unreadable.

It was very useful, Thanks. 👍

Great!
HelpFULL!
I tried to get image from text, but the most of codes gave error.
Only your code SUCCESS.
thanks