Chapter 4. Examples
This chapter demonstrates the use of AMQ C++ through example programs. To run them, make sure you have completed the steps in the Chapter 2, Installation chapter for your environment and you have a running and configured broker.
See the Qpid Proton C++ examples for more sample programs.
4.1. Sending Messages
This client program connects to a server using CONNECTION_URL, creates a sender for target ADDRESS, sends a message containing MESSAGE_BODY, closes the connection, and exits.
Example: Sending Messages
#include <proton/connection.hpp>
#include <proton/container.hpp>
#include <proton/message.hpp>
#include <proton/messaging_handler.hpp>
#include <proton/sender.hpp>
#include <proton/target.hpp>
#include <iostream>
#include <string>
struct send_handler : public proton::messaging_handler {
std::string conn_url_ {};
std::string address_ {};
std::string message_body_ {};
void on_container_start(proton::container& cont) override {
cont.connect(conn_url_);
}
void on_connection_open(proton::connection& conn) override {
conn.open_sender(address_);
}
void on_sender_open(proton::sender& snd) override {
std::cout << "SEND: Opened sender for target address '"
<< snd.target().address() << "'\n";
}
void on_sendable(proton::sender& snd) override {
proton::message msg {message_body_};
snd.send(msg);
std::cout << "SEND: Sent message '" << msg.body() << "'\n";
snd.close();
snd.connection().close();
}
};
int main(int argc, char** argv) {
if (argc != 4) {
std::cerr << "Usage: send CONNECTION-URL ADDRESS MESSAGE-BODY\n";
return 1;
}
send_handler handler {};
handler.conn_url_ = argv[1];
handler.address_ = argv[2];
handler.message_body_ = argv[3];
proton::container cont {handler};
try {
cont.run();
} catch (const std::exception& e) {
std::cerr << e.what() << "\n";
return 1;
}
return 0;
}
Running the Example
To run the example program, copy it to a local file, compile it, and execute it from the command line.
$ g++ send.cpp -o send -std=c++11 -lstdc++ -lqpid-proton-cpp $ ./send amqp://localhost queue1 hello
4.2. Receiving Messages
This client program connects to a server using CONNECTION_URL, creates a receiver for source ADDRESS, and receives messages until it is terminated or it reaches COUNT messages.
Example: Receiving Messages
#include <proton/connection.hpp>
#include <proton/container.hpp>
#include <proton/delivery.hpp>
#include <proton/message.hpp>
#include <proton/messaging_handler.hpp>
#include <proton/receiver.hpp>
#include <proton/source.hpp>
#include <iostream>
#include <string>
struct receive_handler : public proton::messaging_handler {
std::string conn_url_ {};
std::string address_ {};
int desired_ {0};
int received_ {0};
void on_container_start(proton::container& cont) override {
cont.connect(conn_url_);
}
void on_connection_open(proton::connection& conn) override {
conn.open_receiver(address_);
}
void on_receiver_open(proton::receiver& rcv) override {
std::cout << "RECEIVE: Opened receiver for source address '"
<< rcv.source().address() << "'\n";
}
void on_message(proton::delivery& dlv, proton::message& msg) override {
std::cout << "RECEIVE: Received message '" << msg.body() << "'\n";
received_++;
if (received_ == desired_) {
dlv.receiver().close();
dlv.connection().close();
}
}
};
int main(int argc, char** argv) {
if (argc != 3 && argc != 4) {
std::cerr << "Usage: receive CONNECTION-URL ADDRESS [MESSAGE-COUNT]\n";
return 1;
}
receive_handler handler {};
handler.conn_url_ = argv[1];
handler.address_ = argv[2];
if (argc == 4) {
handler.desired_ = std::stoi(argv[3]);
}
proton::container cont {handler};
try {
cont.run();
} catch (const std::exception& e) {
std::cerr << e.what() << "\n";
return 1;
}
return 0;
}
Running the Example
To run the example program, copy it to a local file, compile it, and execute it from the command line.
$ g++ receive.cpp -o receive -std=c++11 -lstdc++ -lqpid-proton-cpp $ ./receive amqp://localhost queue1
