android app的后端程序向微信后台获取unionid返回微信API调用失败: {"errcode":40029,"errmsg":"invalid code, rid: 69f5ccff-1c5229ed-34347d87"}，已检查appid和appsecret都对，且已绑定开放平台账号

// 调用微信接口

String urlStr = String.format("%s?appid=%s&secret=%s&js_code=%s&grant_type=authorization_code",

WECHAT_API_URL, appId, appSecret, code);

URL url = new URL(urlStr);

HttpURLConnection conn = (HttpURLConnection) url.openConnection();

conn.setRequestMethod("GET");

conn.setConnectTimeout(CONNECT_TIMEOUT);

conn.setReadTimeout(READ_TIMEOUT);

// 读取响应

StringBuilder response = new StringBuilder();

try (BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8"))) {

String line;

while ((line = reader.readLine()) != null) {

response.append(line);

}

}