Code Notes made by Vaibhav Rathod

POCO (C++ Portable Components)

2 min read

Written by Vaibhav Rathod

History

  • Who: Created by Günter Obiltschnig at Applied Informatics Software Engineering GmbH.
  • Why: To provide a comprehensive set of C++ class libraries for building networked, portable applications — similar to what Java’s standard library offers but for C++.
  • When: First released in 2004. Actively maintained.

Introduction

What is POCO?

  • A collection of open-source C++ class libraries for building networked, portable applications.
  • Covers HTTP, FTP, SMTP, JSON, XML, SQL, threading, filesystem, and more.
  • Website: pocoproject.org

Advantages

  • Comprehensive — covers networking, data, threading, and utilities in one library.
  • Cross-platform: Windows, Linux, macOS, embedded.
  • Clean, consistent C++ API.
  • Good documentation and active community.

Disadvantages

  • Large dependency for simple use cases.
  • Requires compilation (not header-only).
  • Some APIs feel dated compared to modern C++17/20.

Installation & Setup

apt (Ubuntu)

sudo apt install libpoco-dev

vcpkg

vcpkg install poco

CMake

find_package(Poco REQUIRED COMPONENTS Net JSON XML Data)
target_link_libraries(MyApp Poco::Net Poco::JSON Poco::XML Poco::Data)

Core Concepts

HTTP Client

#include <Poco/Net/HTTPClientSession.h>
#include <Poco/Net/HTTPRequest.h>
#include <Poco/Net/HTTPResponse.h>
#include <Poco/StreamCopier.h>
#include <iostream>
 
Poco::Net::HTTPClientSession session("example.com", 80);
 
Poco::Net::HTTPRequest request(
    Poco::Net::HTTPRequest::HTTP_GET,
    "/",
    Poco::Net::HTTPMessage::HTTP_1_1
);
request.setContentLength(0);
session.sendRequest(request);
 
Poco::Net::HTTPResponse response;
std::istream& rs = session.receiveResponse(response);
 
std::cout << response.getStatus() << " " << response.getReason() << "\n";
Poco::StreamCopier::copyStream(rs, std::cout);

JSON Parsing

#include <Poco/JSON/Parser.h>
#include <Poco/JSON/Object.h>
 
std::string json = R"({"name":"Alice","age":30,"active":true})";
 
Poco::JSON::Parser parser;
Poco::Dynamic::Var result = parser.parse(json);
Poco::JSON::Object::Ptr obj = result.extract<Poco::JSON::Object::Ptr>();
 
std::string name = obj->getValue<std::string>("name");
int age = obj->getValue<int>("age");
bool active = obj->getValue<bool>("active");
 
std::cout << name << ", " << age; // Alice, 30

Threading

#include <Poco/Thread.h>
#include <Poco/Runnable.h>
 
class MyTask : public Poco::Runnable {
public:
    void run() override {
        std::cout << "Running in thread\n";
    }
};
 
MyTask task;
Poco::Thread thread;
thread.start(task);
thread.join();

More Learn

Graph View

Backlinks

Recently Updated