获取小程序码

 public String yaoqing(){

    jsonresult = new JsonResult();

    String openid = request.getParameter("openid");

    Peizhi peizhi = DAO.findbyid(Peizhi.class, 1);

    String URL = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid="+peizhi.getAppid()+"&secret="+peizhi.getAppsecret()+"";

//    String URL = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=wxe185e021a4367b1b&secret=067cc348c2c196fa245d350503f71d05";

    String text = CommonUtil.httpsRequest2(URL, "GET", null);

    Gson gson = new Gson();  

Map<String, String> map = new HashMap<String, String>();  

map = gson.fromJson(text, map.getClass());  

String access_token = map.get("access_token");

CommonUtil.xiaochengxuma(access_token,openid);

    return "jsonresult";

    }

public static void xiaochengxuma(String access_token,String openid){
try
{
URL url = new URL("https://api.weixin.qq.com/wxa/getwxacodeunlimit?access_token="+access_token);
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
httpURLConnection.setRequestMethod("POST");// 提交模式
// conn.setConnectTimeout(10000);//连接超时 单位毫秒
// conn.setReadTimeout(2000);//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());
// 发送请求参数
JSONObject paramJson = new JSONObject();
paramJson.put("scene", openid);
paramJson.put("page", "pages/huoqu/huoqu");
// paramJson.put("width", 430);
// paramJson.put("auto_color", true);
/**
* line_color生效
* paramJson.put("auto_color", false);
* JSONObject lineColor = new JSONObject();
* lineColor.put("r", 0);
* lineColor.put("g", 0);
* lineColor.put("b", 0);
* paramJson.put("line_color", lineColor);
* */

printWriter.write(paramJson.toString());
System.out.println(paramJson.toString());
// flush输出流的缓冲
printWriter.flush();
//开始获取数据
BufferedInputStream bis = new BufferedInputStream(httpURLConnection.getInputStream());
String root=ServletActionContext.getServletContext().getRealPath("upload");
OutputStream os = new FileOutputStream(new File(root,openid.substring(2, 8)+".png"));
int len;
byte[] arr = new byte[1024];
while ((len = bis.read(arr)) != -1)
{
os.write(arr, 0, len);
os.flush();
}
os.close();
}
catch (Exception e)
{
e.printStackTrace();
}
}