SSE Spring Boot Demo

Small sse-eventbus demo using Spring Boot.

The application publishes server-sent events every five seconds and includes a small browser client served by Spring Boot.

Requirements

• Java 25 or newer
• Maven Wrapper included in this repository

Run

./mvnw spring-boot:run

On Windows:

.\mvnw.cmd spring-boot:run

Browser Client

After the application starts, open:

http://localhost:8080/

The page lets you enter a client id, connect to the backend, disconnect, and view the two event streams published by the demo.

SSE Endpoint

The browser client connects to this endpoint:

GET http://localhost:8080/register/{id}

{id} is the client id used by sse-eventbus.

The endpoint subscribes the client to these events:

• message: JSON array with five random integers from 0 to 30
• dto: JSON object, currently {"i":10,"s":"test"}

The first events are published after an initial two-second delay. New events are published every five seconds after that.

Custom Client Example

const source = new EventSource("http://localhost:8080/register/demo-client");

source.onmessage = event => {
  console.log("message", JSON.parse(event.data));
};

source.addEventListener("dto", event => {
  console.log("dto", JSON.parse(event.data));
});