Question

当我在没有网络连接的情况下运行以下代码时，我在最后一行遇到错误的访问错误。

Poco::URI uri(sRemoteLoggingURL);

HTTPClientSession session(uri.getHost(), uri.getPort());

HTTPRequest request(HTTPRequest::HTTP_POST, uri.getPathAndQuery());

request.set("User-Agent", "Poco");

string reqBody = "{\"logMessage\":\""+ message + "\", \"application_name\":\""+ sAppName +"\"}";
request.setContentLength( reqBody.length() );

std::ostream& sessionStream = session.sendRequest(request);

这是预期的行为吗？在尝试发送请求之前，是否需要检查网络连接？如果是这样，我该怎么做？我已尝试session.connected()，但即使我有网络连接，也会返回false。

Answer 1

我想我明白了。显然，如果有异常，您需要确保在销毁之前（或在它超出范围之前）在会话上调用reset。此代码有效：

Poco::URI uri(sRemoteLoggingURL);

HTTPClientSession session(uri.getHost(), uri.getPort());

try{

  HTTPRequest request(HTTPRequest::HTTP_POST, uri.getPathAndQuery());

  request.set("User-Agent", "Poco");

  string reqBody = "{\"logMessage\":\""+ message + "\", \"application_name\":\""+ sAppName +"\"}";
  request.setContentLength( reqBody.length() );

  std::ostream& sessionStream = session.sendRequest(request);


  if (sessionStream.good()) {

    sessionStream << reqBody;

    HTTPResponse res;

    string text;
    istream &is = session.receiveResponse(res);
    StreamCopier::copyToString(is, text);
  }

}catch(Poco::Exception& e){
  // apparently, you MUST call reset before destroying the session, or you'll crash
  session.reset();
  sdfLog::logFormat("appContent::doIdle Poco::Exception: %s\n", e.what());
}catch(...){
  session.reset();
  sdfLog::logFormat("appContent::doIdle exception in remote logger %s\n");
}

网络连接丢失时Poco :: Net :: HTTPClientSession中的访问异常错误

1 个答案: