package com.xzx.gc.common.utils.image;

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.servlet.http.HttpServletResponse;
import java.util.HashMap;
import java.util.Map;

/**
 * 生成二维码图片流
 *
 * @author zhu
 *
 */
public class QRCodeUtil {

    public static BitMatrix generateQRCodeStream(String content,HttpServletResponse response) {
        //给相应添加头部信息，主要告诉浏览器返回的是图片流
        response.setHeader("Cache-Control", "no-store");
        // 不设置缓存
        response.setHeader("Pragma", "no-cache");
        response.setDateHeader("Expires", 0);
        response.setContentType("image/png");
        //设置图片的文字编码以及内边框
        Map<EncodeHintType, Object> hints = new HashMap<>();
        //编码
        hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
        //边框距
        hints.put(EncodeHintType.MARGIN, 0);
        BitMatrix bitMatrix;
        try {
            //参数分别为：编码内容、编码类型、图片宽度、图片高度，设置参数
            bitMatrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, 300, 300,hints);
        }catch(WriterException e) {
            e.printStackTrace();
            return null;
        }
        return bitMatrix;

    }

}