java用谷歌的zxing包制作二维码

1.pom.xml导入zxing依赖

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

2.写工具类QRUtil

package contorller;

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.io.OutputStream;

public class QRUtil{
private static final int BLACK = 0xFF000000;
private static final int WHITE = 0xFFFFFFFF;

private QRUtil() {}


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);
        System.out.println(image);
        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);
        }
        }
        }

3.写testQR，直接生成在d盘可以看到有一个lirixing.png

package contorller;

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

import java.io.File;
import java.util.Hashtable;

public class testQR {
    public static void main(String []args)throws Exception{
        String text="https://blog.csdn.net/LRXmrlirixing";
        int width=300;
        int height=300;
        String format="gif";
        Hashtable hints=new Hashtable();
        hints.put(EncodeHintType.CHARACTER_SET,"utf-8");
        BitMatrix bitMatrix=new MultiFormatWriter().encode(text, BarcodeFormat.QR_CODE,width,height,hints);
        File outputFile=new File("d:"+File.separator+"lirixing.png");
        QRUtil.writeToFile(bitMatrix,format,outputFile);

    }
}

4.可以看到d盘有这个二维码图片