Implementation:ClickHouse ClickHouse Poco HTTPResponse

Knowledge Sources	ClickHouse Poco Documentation
Domains	Networking, HTTP
Last Updated	2026-02-08 00:00 GMT

Overview

Encapsulation of HTTP response messages with status codes, reason phrases, headers, and cookie management.

Description

The Poco `HTTPResponse` class represents an HTTP response message extending `HTTPMessage` to add response-specific properties: status code and reason phrase. It provides comprehensive support for HTTP status codes (100-511), methods to manage response headers (including `Date` and `Set-Cookie`), and cookie extraction.

The class defines enumerations for all standard HTTP status codes from informational (100s) through server errors (500s), with corresponding reason phrases. It supports reading responses from input streams and writing them to output streams, making it suitable for both client and server implementations.

Usage

ClickHouse uses this vendored component to handle HTTP responses when acting as an HTTP client or processing responses in HTTP-related functionality. It's used in conjunction with `HTTPClientSession` to parse and interpret server responses.

Code Reference

Source Location

• Repository: ClickHouse
• File: base/poco/Net/include/Poco/Net/HTTPResponse.h
• Lines: 1-309

Signature

class HTTPResponse : public HTTPMessage {
public:
    enum HTTPStatus {
        HTTP_CONTINUE = 100,
        HTTP_SWITCHING_PROTOCOLS = 101,
        HTTP_OK = 200,
        HTTP_CREATED = 201,
        HTTP_NO_CONTENT = 204,
        HTTP_MOVED_PERMANENTLY = 301,
        HTTP_FOUND = 302,
        HTTP_NOT_MODIFIED = 304,
        HTTP_BAD_REQUEST = 400,
        HTTP_UNAUTHORIZED = 401,
        HTTP_FORBIDDEN = 403,
        HTTP_NOT_FOUND = 404,
        HTTP_INTERNAL_SERVER_ERROR = 500,
        HTTP_NOT_IMPLEMENTED = 501,
        HTTP_SERVICE_UNAVAILABLE = 503
        // ... and many more status codes
    };

    HTTPResponse();
    HTTPResponse(HTTPStatus status, const std::string& reason);
    HTTPResponse(const std::string& version, HTTPStatus status, const std::string& reason);
    HTTPResponse(HTTPStatus status);

    void setStatus(HTTPStatus status);
    HTTPStatus getStatus() const;
    void setReason(const std::string& reason);
    const std::string& getReason() const;
    void setStatusAndReason(HTTPStatus status, const std::string& reason);
    void setStatusAndReason(HTTPStatus status);

    void setDate(const Poco::Timestamp& dateTime);
    Poco::Timestamp getDate() const;

    void addCookie(const HTTPCookie& cookie);
    void getCookies(std::vector<HTTPCookie>& cookies) const;

    void write(std::ostream& ostr) const;
    void read(std::istream& istr);

    static const std::string& getReasonForStatus(HTTPStatus status);
};

Import

#include <Poco/Net/HTTPResponse.h>

I/O Contract

Input	Output
Status code and optional reason phrase	Configured HTTP response object
Input stream with HTTP response	Parsed response with status, headers, cookies
Response object with headers	HTTP response text written to output stream

HTTP Status Code Ranges

Range	Category	Examples
100-199	Informational	100 Continue, 101 Switching Protocols
200-299	Success	200 OK, 201 Created, 204 No Content
300-399	Redirection	301 Moved Permanently, 302 Found, 304 Not Modified
400-499	Client Error	400 Bad Request, 401 Unauthorized, 404 Not Found
500-599	Server Error	500 Internal Server Error, 503 Service Unavailable

Usage Examples

// Client-side: receiving response
HTTPClientSession session("www.example.com");
HTTPRequest request(HTTPRequest::HTTP_GET, "/");
session.sendRequest(request);

HTTPResponse response;
std::istream& rs = session.receiveResponse(response);

std::cout << "Status: " << response.getStatus() << std::endl;
std::cout << "Reason: " << response.getReason() << std::endl;
std::cout << "Content-Type: " << response.getContentType() << std::endl;

if (response.getStatus() == HTTPResponse::HTTP_OK) {
    // Read response body
    std::string body;
    Poco::StreamCopier::copyToString(rs, body);
}

// Extract cookies from response
std::vector<HTTPCookie> cookies;
response.getCookies(cookies);
for (const auto& cookie : cookies) {
    std::cout << "Cookie: " << cookie.getName()
              << "=" << cookie.getValue() << std::endl;
}

// Server-side: creating response
HTTPResponse serverResponse(HTTPResponse::HTTP_OK);
serverResponse.setContentType("application/json");
serverResponse.setDate(Poco::Timestamp());

HTTPCookie cookie("session_id", "abc123");
cookie.setPath("/");
cookie.setMaxAge(3600);
serverResponse.addCookie(cookie);

std::ostringstream oss;
serverResponse.write(oss);

// Check status category
if (response.getStatus() >= 400) {
    std::cerr << "Error response: "
              << HTTPResponse::getReasonForStatus(response.getStatus())
              << std::endl;
}

Related Pages

• Principle:ClickHouse_ClickHouse_HTTP_Client_Communication