java 生成二维码

用google的zxing

<dependency>
  <groupId>com.google.zxing</groupId>
  <artifactId>core</artifactId>
  <version>3.3.0</version>
</dependency>

import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.util.Hashtable;

import javax.imageio.ImageIO;

import org.apache.commons.codec.binary.Base64;
import org.apache.commons.lang3.StringUtils;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;

public class BarCodeUtil {

    private static final int BLACK = 0xFF000000;
    private static final int WHITE = 0xFFFFFFFF;
    private static int IMG_WIDTH = 300;
    private static int IMG_HEIGHT = 300;

    public static void main(String[] args) {
        System.out.println(genBarCodeToBase64("二维码文字内容", "E:/barcode-logo.png"));
        genBarCodeToFile("二维码文字内容", "E:/barcode-logo.png");
    }

    /**
     * 生成二维码图片,不带logo,返回图片的base64编码
     * @param text
     * @return
     */
    public static String genBarCodeToBase64(String text) {
        return genBarCodeToBase64(text, null);
    }

    /**
     * 生成二维码图片,带logo,返回图片的base64编码
     * @param text
     * @return
     */
    public static String genBarCodeToBase64(String text, String logopath) {
        Hashtable<EncodeHintType, Object> hints = new Hashtable<EncodeHintType, Object>();
        hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
        //容错率设置为高,手机像素差点的也能扫出来
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
        try {
            BitMatrix bitMatrix = new MultiFormatWriter().encode(text, BarcodeFormat.QR_CODE, IMG_WIDTH, IMG_HEIGHT,
                    hints);
            byte[] arr = toByteArray(bitMatrix, logopath);
            return Base64.encodeBase64String(arr);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 生成为本地文件,带logo
     */
    public static void genBarCodeToFile(String text, String logoPath) {
        Hashtable<EncodeHintType, Object> hints = new Hashtable<EncodeHintType, Object>();
        hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
        BitMatrix bitMatrix;
        try {
            bitMatrix = new MultiFormatWriter().encode(text, BarcodeFormat.QR_CODE, IMG_WIDTH, IMG_HEIGHT, hints);
            writeToFile(bitMatrix, "png", new File("E:/new.png"), logoPath);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private static byte[] toByteArray(BitMatrix matrix, String logopath) throws IOException {
        BufferedImage image = toBufferedImage(matrix);
        
        //增加logo 
        if (StringUtils.isNotBlank(logopath)) {
            Graphics2D gs = image.createGraphics();
            BufferedImage img = ImageIO.read(new File(logopath));
            gs.drawImage(img, IMG_WIDTH / 2 - img.getWidth() / 2, IMG_WIDTH / 2 - img.getHeight() / 2, null);
            gs.dispose();
            img.flush();
        }
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        try {
            ImageIO.write(image, "png", out);
            return out.toByteArray();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

    private static void writeToFile(BitMatrix matrix, String format, File file, String logoPath) throws IOException {
        BufferedImage image = toBufferedImage(matrix);
        //增加logo
        if (StringUtils.isNotBlank(logoPath)) {
            Graphics2D gs = image.createGraphics();
            BufferedImage img = ImageIO.read(new File(logoPath));
            gs.drawImage(img, IMG_WIDTH / 2 - img.getWidth() / 2, IMG_WIDTH / 2 - img.getHeight() / 2, null);
            gs.dispose();
            img.flush();
        }
        if (!ImageIO.write(image, format, file)) {
            throw new IOException("Could not write an image of format " + format + " to " + file);
        }
    }

    private static BufferedImage toBufferedImage(BitMatrix matrix) {
        int width = matrix.getWidth();
        int height = matrix.getHeight();
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

        for (int x = 0; x < width; x++) {
            for (int y = 0; y < height; y++) {
                image.setRGB(x, y, matrix.get(x, y) ? BLACK : WHITE);
            }
        }
        return image;
    }

}