import cn.api.commons.commons.util.MatrixToImageWriter;

import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;

/**
 * @author wenjq
 * @data 2018/10/18 20:23
 */
public class test {

    public static void main(String[] args){

        InputStream inputStream = null;
        try {
            //這裡放的是需要放入二維碼的資訊
            inputStream = MatrixToImageWriter.creatImage("www.baidu.com");
            byte[] bytes = new byte[inputStream.available()];
            inputStream.read(bytes);
            File file = new File("E:\\demo\\二維碼.jpg");
            FileOutputStream outputStream = new FileOutputStream(file);
            outputStream.write(bytes);
        } catch (Exception e) {
            e.printStackTrace();
        }



    }

}
 

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


import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.*;
import java.util.Hashtable;

/**
 * 用於生成二維碼圖片
 */
public class MatrixToImageWriter {
    private static final int BLACK = 0xFF000000;
    private static final int WHITE = 0xFFFFFFFF;

    private MatrixToImageWriter() {
    }

    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);
        }
    }

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

    public static InputStream creatImage(String text) throws Exception

    {
        // text = "http://www.baidu.com"; // 二維碼內容
        int width = 300; // 二維碼圖片寬度
        int height = 300; // 二維碼圖片高度
        String format = "jpg";// 二維碼的圖片格式

        Hashtable<EncodeHintType, String> hints = new Hashtable<>();
        hints.put(EncodeHintType.CHARACTER_SET, "utf-8"); // 內容所使用字符集編碼

        BitMatrix bitMatrix = new MultiFormatWriter().encode(text,
                BarcodeFormat.QR_CODE, width, height, hints);

        ByteArrayOutputStream out = new ByteArrayOutputStream();
        MatrixToImageWriter.writeToStream(bitMatrix, format, out);

        return new ByteArrayInputStream(out.toByteArray());
    }


}