Java获取微信小程序二维码

/*
* 获取二维码
* 这里的 post 方法 为 json post【重点】
*/
@RequestMapping("/getCode")
public ResponseMsg getCodeM(HttpServletRequest request) throws Exception { String imei ="867186032552993";
String page="page/msg_waist/msg_waist";
String token = getToken(); // 得到token Map<String, Object> params = new HashMap<>();
params.put("scene", imei); //参数
params.put("page", "page/msg_waist/msg_waist"); //位置
params.put("width", 430); CloseableHttpClient httpClient = HttpClientBuilder.create().build(); HttpPost httpPost = new HttpPost("https://api.weixin.qq.com/wxa/getwxacodeunlimit?access_token="+token); // 接口
httpPost.addHeader(HTTP.CONTENT_TYPE, "application/json");
String body = JSON.toJSONString(params); //必须是json模式的 post
StringEntity entity;
entity = new StringEntity(body);
entity.setContentType("image/png"); httpPost.setEntity(entity);
HttpResponse response; response = httpClient.execute(httpPost);
InputStream inputStream = response.getEntity().getContent();
String name = imei+".png";
saveToImgByInputStream(inputStream,"D:\\",name); //保存图片
return null;
} /*
* 获取 token
* 普通的 get 可获 token
*/
public String getToken() {
try { Map<String, String> map = new LinkedHashMap<String, String>();
map.put("grant_type", grant_type);
map.put("appid", appid);
map.put("secret", secret); String rt = HttpUtils.sendGet(TOKEN_URL, map); System.out.println(rt);
JSONObject json = JSONObject.parseObject(rt); if (json.getString("access_token") != null || json.getString("access_token") != "") {
return json.getString("access_token");
} else {
return null;
}
} catch (Exception e) {
log.error("# 获取 token 出错... e:" + e);
e.printStackTrace();
return null;
} } /**
* 将二进制转换成文件保存
* @param instreams 二进制流
* @param imgPath 图片的保存路径
* @param imgName 图片的名称
* @return
* 1：保存正常
* 0：保存失败
*/
public static int saveToImgByInputStream(InputStream instreams,String imgPath,String imgName){
int stateInt = 1;
if(instreams != null){
try {
File file=new File(imgPath,imgName);//可以是任何图片格式.jpg,.png等
FileOutputStream fos=new FileOutputStream(file);
byte[] b = new byte[1024];
int nRead = 0;
while ((nRead = instreams.read(b)) != -1) {
fos.write(b, 0, nRead);
}
fos.flush();
fos.close();
} catch (Exception e) {
stateInt = 0;
e.printStackTrace();
} finally {
}
}
return stateInt;
}