This guide shows you how to stand up a sample Hello World application, built with Spring Boot, that connects to EventStoreDB.

The sample exposes a simple HTTP endpoint http://localhost:8080/hello-world?visitor={visitor} that shows how to append to and read from a stream in EventStoreDB.

When a visitor says hello via hello-world?visitor={visitor}, an event is appended to a stream to record the fact they have been greeted.

The stream is then read from beginning to end to return the full log of visitors on each call to /hello-world?visitor={visitor}.

You can see how this is done in the source code here.

Before running the application, make sure you have the following installed on your system:

• Docker: Get Docker
• Docker Compose: Install Docker Compose

1. Clone the repository:

   git clone https://github.com/EventStore/samples.git
   cd samples/Quickstart/Java/esdb-sample-springboot
   

2. Run the application and database using Docker Compose:

   docker compose up -d
   

3. Verify the containers are up and running:

   docker compose ps
   

   Output:

   NAME                                              IMAGE                          ...   STATUS                   PORTS
   esdb-sample-springboot-esdb-local-1               eventstore/eventstore:latest   ...   Up 7 seconds (healthy)   1112-1113/tcp, 0.0.0.0:2113->2113/tcp
   esdb-sample-springboot-esdb-sample-springboot-1   esdb-sample-springboot         ...   Up 7 seconds             0.0.0.0:8080->8080/tcp
   

4. Test the application:

   Say hello as Ouro:

   curl "localhost:8080/hello-world?visitor=Ouro"
   

   Say hello as YourName:

   curl "localhost:8080/hello-world?visitor=YourName"
   

   Output:

   1 visitors have been greeted, they are: [Ouro]
   

   2 visitors have been greeted, they are: [Ouro, YourName]
   

5. To stop and remove the containers, use:

   docker compose down
   

For more in-depth and detailed examples of using EventStoreDB and the Java Client, refer to:

• EventStoreDB: Getting Started With EventStoreDB
• Java Client: Java Client Samples