微信小程序生成带参二维码

场景：实现微信小程序中的海报功能，海报中有一个通过扫码跳转到自己小程序的二维码，用户保存海报到本地在朋友圈分享后就可以通过扫码进入小程序。

• 生成二维码工具类代码如下：

 package com.aone.foottalk.action.wx.util;

 import java.io.File;
 import java.io.FileOutputStream;
 //import java.io.IOException;
 import java.io.InputStream;
 import java.util.HashMap;
 import java.util.Map;

 //import org.apache.commons.io.IOUtils;
 import org.apache.http.HttpResponse;
 import org.apache.http.client.methods.HttpPost;
 import org.apache.http.entity.StringEntity;
 import org.apache.http.impl.client.CloseableHttpClient;
 import org.apache.http.impl.client.HttpClientBuilder;
 import org.apache.http.protocol.HTTP;

 import com.alibaba.fastjson.JSON;
 //import com.aone.foottalk.action.back.image.ImgTAction;
 //import com.aone.foottalk.common.QiniuUtil;

 import net.sf.json.JSONObject;
 /**
  * 二维码工具
  * @author 开发
  *
  */
 public class AUtil {

     public static String getminiqrQr(String neirong,String tzdz) throws Exception{
         String dizhi="";//返回给前端的地址
         /*************获取小程序token值*******************/
         String access_token ="";
         // 小程序(商城)
         String appId = "***************";
         String secret = "***************";
         String url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=" + appId + "&secret=" + secret;
         JSONObject json = CommonUtil.httpsRequest(url, "GET", null);
         if (null != json) {
             access_token=json.getString("access_token");
         }
         System.out.println("token"+access_token);
         /********************************/
         Map<String, Object> params = new HashMap<>();
         params.put("scene", neirong);
         params.put("page", "pages"+"/"+tzdz+"/"+tzdz);
         params.put("width", 430);

         CloseableHttpClient  httpClient = HttpClientBuilder.create().build();
         HttpPost httpPost = new HttpPost("https://api.weixin.qq.com/wxa/getwxacodeunlimit?access_token="+access_token);
         httpPost.addHeader(HTTP.CONTENT_TYPE, "application/json");
         String body = JSON.toJSONString(params);
         StringEntity entity;
         entity = new StringEntity(body);
         entity.setContentType("image/png");
         httpPost.setEntity(entity);

         HttpResponse response;
         response = httpClient.execute(httpPost);
         InputStream inputStream = response.getEntity().getContent();
         /**===========================上传七牛==================================**/
         /*try {
             byte[] data = IOUtils.toByteArray(inputStream);
             Map<String, String> map = QiniuUtil.upload(data, neirong);
             String code = map.get("code");
             if ("200".equals(code)) {
                 System.out.println(map.get("path"));
                 dizhi=map.get("path");
                 System.out.println("地址："+dizhi);
             }
         } catch (IOException ex) {
             System.out.println(ImgTAction.class.getName() + "has thrown an exception: " + ex.getMessage());
         } finally {
             try {
                 inputStream.close();
             } catch (IOException ignored) {

             }
         }*/
         /**============================保存到本地=================================**/
         File targetFile = new File("/photo");
         if(!targetFile.exists()){
             targetFile.mkdirs();
         }
         FileOutputStream out = new FileOutputStream("/888.png");

         byte[] buffer = new byte[8192];
         int bytesRead = 0;
         while((bytesRead = inputStream.read(buffer, 0, 8192)) != -1) {
             out.write(buffer, 0, bytesRead);
         }
         out.flush();
         out.close();
         return dizhi;
     }

     public static void main(String args[]){
         try {
             getminiqrQr("333","index");
         } catch (Exception e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
     }
 }

• 通用工具类：

 package com.aone.foottalk.action.wx.util;

 import java.io.BufferedReader;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.OutputStream;
 import java.net.ConnectException;
 import java.net.URL;
 import java.util.Formatter;

 import javax.net.ssl.HttpsURLConnection;
 import javax.net.ssl.SSLContext;
 import javax.net.ssl.SSLSocketFactory;
 import javax.net.ssl.TrustManager;

 import net.sf.json.JSONObject;

 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

 /**
  * 通用工具类
  * @author 开发
  *
  */
 public class CommonUtil {
     private static Logger log = LoggerFactory.getLogger(CommonUtil.class);

     // 凭证获取（GET）
     public final static String token_url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=APPID&secret=APPSECRET";

     /**
      * 发送https请求
      *
      * @param requestUrl 请求地址
      * @param requestMethod 请求方式（GET、POST）
      * @param outputStr 提交的数据
      * @return JSONObject(通过JSONObject.get(key)的方式获取json对象的属性值)
      */
     public static JSONObject httpsRequest(String requestUrl, String requestMethod, String outputStr) {
         JSONObject jsonObject = null;
         try {
             // 创建SSLContext对象，并使用我们指定的信任管理器初始化
             TrustManager[] tm = { new MyX509TrustManager() };
             SSLContext sslContext = SSLContext.getInstance("SSL", "SunJSSE");
             sslContext.init(null, tm, new java.security.SecureRandom());
             // 从上述SSLContext对象中得到SSLSocketFactory对象
             SSLSocketFactory ssf = sslContext.getSocketFactory();

             URL url = new URL(requestUrl);
             HttpsURLConnection conn = (HttpsURLConnection) url.openConnection();
             conn.setSSLSocketFactory(ssf);

             conn.setDoOutput(true);
             conn.setDoInput(true);
             conn.setUseCaches(false);
             // 设置请求方式（GET/POST）
             conn.setRequestMethod(requestMethod);

             // 当outputStr不为null时向输出流写数据
             if (null != outputStr) {
                 OutputStream outputStream = conn.getOutputStream();
                 // 注意编码格式
                 outputStream.write(outputStr.getBytes("UTF-8"));
                 outputStream.close();
             }

             // 从输入流读取返回内容
             InputStream inputStream = conn.getInputStream();
             InputStreamReader inputStreamReader = new InputStreamReader(inputStream, "utf-8");
             BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
             String str = null;
             StringBuffer buffer = new StringBuffer();
             while ((str = bufferedReader.readLine()) != null) {
                 buffer.append(str);
             }

             // 释放资源
             bufferedReader.close();
             inputStreamReader.close();
             inputStream.close();
             inputStream = null;
             conn.disconnect();
             jsonObject = JSONObject.fromObject(buffer.toString());
         } catch (ConnectException ce) {
             log.error("连接超时：{}", ce);
         } catch (Exception e) {
             log.error("https请求异常：{}", e);
         }
         return jsonObject;
     }

     /**
      * 方法名：byteToHex</br>
      * 详述：字符串加密辅助方法 </br>
      * 开发人员：souvc  </br>
      * 创建时间：2016-1-5  </br>
      * @param hash
      * @return 说明返回值含义
      * @throws 说明发生此异常的条件
      */
     public static String byteToHex(final byte[] hash) {
         Formatter formatter = new Formatter();
         for (byte b : hash) {
             formatter.format("%02x", b);
         }
         String result = formatter.toString();
         formatter.close();
         return result;
     }
 }

• 注

1. 目前根据已发布小程序的appId与secret所获取的token可以下载到带参的二维码图片，但是没发布的没法得到小程序二维码图片。
2. 小程序下载二维码需要https的图片地址，但是七牛目前是http的，图片保存地址需要处理。