二维码生成

<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>core</artifactId>
    <version>3.3.3</version>
</dependency>

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

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.UUID;

public class QRCodeUtil
{

    public static void main(String[] args) {
        generate("content", "/Users/Downloads/QR");
    }
    
 	/**
     *
     * @param content 内容
     * @param path    保存路劲
     */
    public static void generate(String content, String path){
        String codeName = UUID.randomUUID().toString();// 二维码的图片名
        String imageType = "jpg";// 图片类型
        try {
            MultiFormatWriter multiFormatWriter = new MultiFormatWriter();
            Map<EncodeHintType, String> hints = new HashMap<EncodeHintType, String>();
            hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
            BitMatrix bitMatrix = multiFormatWriter.encode(content, BarcodeFormat.QR_CODE, 400, 400, hints);
            File file1 = new File(path, codeName + "." + imageType);
            writeToFile(bitMatrix, imageType, file1);
        } catch (WriterException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }


    private static final int BLACK = 0xFF000000;
    private static final int WHITE = 0xFFFFFFFF;

    public 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;
    }

    public static void writeToFile(BitMatrix matrix, String format, File file) throws IOException {
        BufferedImage image = toBufferedImage(matrix);
        if (!ImageIO.write(image, format, file)) {
            throw new IOException("Could not write an image of format " + format + " to " + file);
        }
    }
}