Skip to content

demo-service

Directory actions

More options

Directory actions

More options

Latest commit

 

History

History

demo-service

README.md

ClickHouse-Java Demo Service

About

This is an example of a Spring Boot service using ClickHouse client directly and via JPA. Example is an application that requires ClickHouse DB running externally. It can be a Docker or ClickHouse Cloud instance.

How to Run

Initialize DB

Set up a ClickHouse instance.

Example of running with Docker:

docker run -d --name demo-service-db -e CLICKHOUSE_USER=default -e CLICKHOUSE_DEFAULT_ACCESS_MANAGEMENT=1 -e CLICKHOUSE_PASSWORD=secret\
 -p 8123:8123 clickhouse/clickhouse-server

docker ps
# output should be like: 
CONTAINER ID   IMAGE                          COMMAND            CREATED         STATUS         PORTS                                                           NAMES
2abfefc40a84   clickhouse/clickhouse-server   "/entrypoint.sh"   4 seconds ago   Up 2 seconds   9000/tcp, 0.0.0.0:8123->8123/tcp, :::8123->8123/tcp, 9009/tcp   demo-service-db

Example how to run client:

docker exec -it demo-service-db clickhouse-client

Create table (needed for JPA example):

CREATE TABLE ui_events
(
    `id` String,
    `timestamp` DateTime64,
    `event_name` String, 
    `tags` Array(String)
)
ENGINE = MergeTree
ORDER BY timestamp

Run Demo-Service

./gradlew bootRun

Interact with API

Direct Client

To read limit number of rows from system.numbers:

curl http://localhost:8080/direct/dataset/0?limit=100000

JPA

To insert some data:

curl -v -X POST -H "Content-Type: application/json" \
 -d '{"id": "4NAD7B8HH1", "timestamp": "2025-04-07T14:30:00.000Z", "eventName": "Login", "tags": ["security", "activity"]}'\
  http://localhost:8080/events/ui_events

To fetch inserted data:

curl -v -X GET http://localhost:8080/events/ui_events