package com.wsm.common.util;

import com.google.zxing.*;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.QRCodeWriter;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;

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

/**
 * 二维码生成和读的工具类
 *
 */
public class QrCodeUtil {
    /**
     * 生成包含字符串信息的二维码图片
     * @param filePath 文件输出流路径
     * @param content 二维码携带信息
     * @param qrCodeSize 二维码图片大小
     * @param imageFormat 二维码的格式
     * @throws WriterException
     * @throws IOException
     */
    public static boolean createQrCode(String  filePath, String content, int qrCodeSize, String imageFormat) throws WriterException, IOException{
        //设置二维码纠错级别ＭＡＰ
        Hashtable<EncodeHintType, ErrorCorrectionLevel> hintMap = new Hashtable<EncodeHintType, ErrorCorrectionLevel>();
        hintMap.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.L);  // 矫错级别
        QRCodeWriter qrCodeWriter = new QRCodeWriter();
        //创建比特矩阵(位矩阵)的QR码编码的字符串
        BitMatrix byteMatrix = qrCodeWriter.encode(content, BarcodeFormat.QR_CODE, qrCodeSize, qrCodeSize, hintMap);
        // 使BufferedImage勾画QRCode  (matrixWidth 是行二维码像素点)
        int matrixWidth = byteMatrix.getWidth();
        BufferedImage image = new BufferedImage(matrixWidth-200, matrixWidth-200, BufferedImage.TYPE_INT_RGB);
        image.createGraphics();
        Graphics2D graphics = (Graphics2D) image.getGraphics();
        graphics.setColor(Color.WHITE);
        graphics.fillRect(0, 0, matrixWidth, matrixWidth);
        // 使用比特矩阵画并保存图像
        graphics.setColor(Color.BLACK);
        for (int i = 0; i < matrixWidth; i++){
            for (int j = 0; j < matrixWidth; j++){
                if (byteMatrix.get(i, j)){
                    graphics.fillRect(i-100, j-100, 1, 1);
                }
            }
        }
        OutputStream outputStream=new FileOutputStream(new File(filePath));
        return ImageIO.write(image, imageFormat, outputStream);
    }

    /**
     * 测试代码
     * @throws WriterException
     */
    public static void main(String[] args) throws IOException, WriterException {
        createQrCode("d:\\qrcode.jpg","china is good",900,"JPEG");
//        createQrCode("src\\main\\webapp\\qrcode\\qrcode.jpg","china is good",900,"JPEG");
    }
}
