POCO C++ Libraries

Language: CPP

Web

POCO was created by Günter Obiltschnig in 2005 to simplify C++ development for networked and portable applications. It focuses on providing robust, reusable, and modern C++ components while remaining lightweight and easy to integrate.

POCO (Portable Components) is a set of modern C++ libraries that provide building blocks for network-centric, portable applications. It includes modules for networking, HTTP, XML, JSON, threading, file system access, and more.

Installation

linux: sudo apt install libpoco-dev
mac: brew install poco
windows: Download precompiled binaries or build from source: https://pocoproject.org/download.html

Usage

POCO offers modules such as Foundation (core utilities), Net (networking), NetSSL (SSL/TLS), Util (configuration and logging), JSON, and XML. It supports asynchronous programming, HTTP clients/servers, file system utilities, and more.

Using POCO HTTP Client

#include <Poco/Net/HTTPClientSession.h>
#include <Poco/Net/HTTPRequest.h>
#include <Poco/Net/HTTPResponse.h>
#include <Poco/StreamCopier.h>
#include <iostream>
#include <sstream>

int main() {
    Poco::Net::HTTPClientSession session("www.example.com");
    Poco::Net::HTTPRequest req(Poco::Net::HTTPRequest::HTTP_GET, "/");
    session.sendRequest(req);
    Poco::Net::HTTPResponse res;
    std::istream &is = session.receiveResponse(res);
    std::stringstream ss;
    Poco::StreamCopier::copyStream(is, ss);
    std::cout << ss.str() << std::endl;
    return 0;
}

Performs a simple HTTP GET request using POCO's Net module and prints the response.

Using POCO Filesystem utilities

#include <Poco/File.h>
#include <iostream>

int main() {
    Poco::File file("test.txt");
    if (!file.exists()) {
        file.createFile();
        std::cout << "File created." << std::endl;
    }
    return 0;
}

Checks for the existence of a file and creates it if missing using POCO Foundation utilities.

Multithreading with POCO

// Use Poco::Thread and Poco::Runnable to implement threaded tasks.

JSON parsing and serialization

// Use Poco::JSON::Parser and Poco::JSON::Object to read/write JSON data.

Building an HTTP server

// Use Poco::Net::HTTPServer, HTTPRequestHandler, and HTTPRequestHandlerFactory to create a server.

Error Handling

Poco::IOException: Occurs during file or network I/O. Check paths, network availability, and permissions.
Poco::Net::HTTPException: Thrown for HTTP request/response issues. Verify URLs, request formatting, and server availability.

Best Practices

Use Foundation module for core utilities like threading, timers, and file system operations.

Leverage Net and NetSSL for network programming and secure connections.

Use JSON and XML modules for structured data handling.

Separate logic into reusable components for maintainability.

Properly handle exceptions from POCO modules to avoid runtime crashes.

Official DocsGithub