java-ngrok Example - TCP Server and Client

This is an example project that shows how to easily integrate java-ngrok with a simple TCP Server and Client.

Getting Started

This is an example of a simple TCP ping/pong server. It opens a local socket, uses ngrok to tunnel to that socket, then the client/server communicate via the publicly exposed address.

For this code to run, we first need to go to ngrok’s Reserved TCP Addresses and register an address. Set the HOST and PORT environment variables pointing to that reserved address.

Build the application with:

make build

Start a socket server with:

NGROK_AUTHTOKEN="my-auth-token" PORT=12345 java -jar build/libs/java-ngrok-example-tcp-server-and-client-1.0.0-SNAPSHOT.jar server

It’s now waiting for incoming connections, so start a client in another terminal to send it something. Start a socket client with:

NGROK_AUTHTOKEN="my-auth-token" HOST="1.tcp.ngrok.io" PORT=12345 java -jar build/libs/java-ngrok-example-tcp-server-and-client-1.0.0-SNAPSHOT.jar client

And that’s it! Data was sent and received from a socket via our ngrok tunnel.