转换二维码的两种方式

之前写了一篇生成微信公众号带参数二维码的文章，今天闲来无事，就通过代码实现了生成的过程，因为请求微信接口返回的参数如下：

{"ticket":"gQH47joAAAAAAAAAASxodHRwOi8vd2VpeGluLnFxLmNvbS9xL2taZ2Z3TVRtNzJXV1Brb3ZhYmJJAAIEZ23sUwMEmm3sUw==","url":"http://weixin.qq.com/q/kZgfwMTm72WWPkovabbI"}

我希望拿到URL转换为二维码图片，上网查找资料后有两种实现方式。

第一种是通过后端引入zxing的jar包，在pom中添加依赖

        
            com.google.zxing
            zxingorg
            3.3.2
        

工具类：

import com.google.zxing.common.BitMatrix;
import javax.imageio.ImageIO;
import java.io.File;
import java.io.OutputStream;
import java.io.IOException;
import java.awt.image.BufferedImage;

public final 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);
        }
    }
}

代码如下：

                String path = "C:/Users/Administrator/Desktop/qrCodeImg";
                try {
                    MultiFormatWriter multiFormatWriter = new MultiFormatWriter();
                    Map hints = new HashMap();
                    hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
                    BitMatrix bitMatrix = multiFormatWriter.encode((String) bookShelf.get("qr_code"), BarcodeFormat.QR_CODE, 400, 400, hints);
                    File file1 = new File(path, bookShelf.get("code") + ".jpg");
                    MatrixToImageWriter.writeToFile(bitMatrix, "jpg", file1);
                } catch (Exception e) {
                    e.printStackTrace();
                }

保存到本地的二维码图片示例如下：

第二种就是在页面引入query.qrcode.js。（还需要jQuery的js）text内容就是我们微信请求获取到的URL

示例：