生成小程序二维码

1. 导入依赖

 <!--   工具类     -->
        <dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
            <version>5.7.13</version>
        </dependency>

2.工具类

package com.xiaochi.change.merchant.info.utils;

import cn.hutool.http.HttpUtil;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import lombok.extern.slf4j.Slf4j;

import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;

/**
 * @DESCRIPTION:小程序二维码
 * @USER: zhengshuang
 */
@Slf4j
public class WeixinQRCodeUtils {

    public static String getAccessTokenAsUrl(String appId,String appSecret){
        String tokenStr= HttpUtil.get(ConstantUtils.GET_WEIXINTOKEN_URL+"&appid="+appId+"&secret="+appSecret+"");
        JSONObject jsonObject = JSONObject.parseObject(tokenStr);
        return "?access_token="+jsonObject.getString("access_token");
    }

    /**
     * 下载小程序二维码
     */
    public static String downloadMiniCode(String appId, String appSecret, String pathStr,String certNumber) {
        Map<String, Object> paramMap = new HashMap<>();
        paramMap.put("scene", certNumber);
        paramMap.put("is_hyaline", false);//参数为ture没有底色，false则底色是白色
        paramMap.put("width",1280);
        String imgFilePath = pathStr  + certNumber + ".png";// 新生成的图片
        try {
            URL url = new URL(ConstantUtils.GET_MINICODE_URL + getAccessTokenAsUrl(appId,appSecret));
            HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
            httpURLConnection.setRequestMethod("POST");// 提交模式
            httpURLConnection.setConnectTimeout(10000);//连接超时 单位毫秒
            httpURLConnection.setReadTimeout(10000);//读取超时 单位毫秒
            // 发送POST请求必须设置如下两行
            httpURLConnection.setDoOutput(true);
            httpURLConnection.setDoInput(true);
            // 获取URLConnection对象对应的输出流
            PrintWriter printWriter = new PrintWriter(httpURLConnection.getOutputStream());
            printWriter.write(JSON.toJSONString(paramMap));
            // flush输出流的缓冲
            printWriter.flush();
            //开始获取数据
            BufferedInputStream bis = new BufferedInputStream(httpURLConnection.getInputStream());
            OutputStream os = new FileOutputStream(new File(imgFilePath));
            // OutputStream os = new FileOutputStream(new File("D:/test/2.png"));
            int len;
            //设置缓冲写入
            byte[] arr = new byte[2048];
            while ((len = bis.read(arr)) != -1) {
                os.write(arr, 0, len);
                os.flush();
            }
            os.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return imgFilePath;
    }
    //本地测试
    public static void main(String[] args) {
      downloadMiniCode("自己的appId","自己的appSecret","D:/test/","参数");
    }
}