Simple User CRUD using Scala Lagom Framework

Sample application performing CRUD operation using Lagom Framework. Application uses Elasticsearch as a Database.

NOTE: This application does not use Event Sourcing or CQRS mechanism.

Below are list of tools and techs used:

• scala - 2.12.4
• sbt - 1.2.1
• Lagom - 1.4.9
• Elasticsearch - 6.4.3

Prerequisites

• docker
• sbt

Running the application

Jump to the project root directory and execute below commands:

docker-compose up -d elasticseach

Above command will start elasticsearch docker container. You can check the elasticsearch status from browser using: http://localhost:9200

And then run the application using:

sbt runAll

This will start the application on port 9000. So if you want to check any of the available GET request, then you can hit: http://localhost:9000/API_URL from your browser.

Available APIs in this application:

Create

• url: POST - /api/user/create
• Headers: Content-Type: application/json
• RequestBody:

{
     "firstName": "Jane",
     "lastName": "Doe",
     "email": "[email protected]"
}

• Response:

{
    "id": "e3b25351-0dd0-4679-90d6-fce9148b631b"
    "firstName": "Jane",
    "lastName": "Doe",
    "email": "[email protected]"
}

• Error Codes:
  • returns HTTP 400 - Bad Request if a user with email is already present

Get

• url: GET /api/users/{userId}

• Headers: Content-Type: application/json

• RequestBody: NA

• Response:

{
    "id": "e3b25351-0dd0-4679-90d6-fce9148b631b"
    "firstName": "Jane",
    "lastName": "Doe",
    "email": "[email protected]"
}

• Error Codes:
  • returns HTTP 404 - Not Found if a user for given ID does not exists

Update

• url: POST /api/user/{userId}/update
• Headers: Content-Type: application/json
• RequestBody:

{
    "id": "e3b25351-0dd0-4679-90d6-fce9148b631b"
    "firstName": "Jane",
    "lastName": "Doe",
    "email": "[email protected]"
}

• Response:

{
    "id": "e3b25351-0dd0-4679-90d6-fce9148b631b"
    "firstName": "Jane",
    "lastName": "Doe",
    "email": "[email protected]"
}

• Error Codes:
  • returns HTTP 404 - Not Found if a user for given ID does not exists

DELETE

• url: GET /api/user/{userId}/delete

• Headers: Content-Type: application/json

• RequestBody: NA

• Response: HTTP 200 OK

• Error Codes:

  • returns HTTP 404 - Not Found if a user for given ID does not exists

Search

• url: POST /api/users?pageNumber=???&pageSize=???
• Headers: Content-Type: application/json
• RequestBody:

{
    "keyword": "jane"
}

• Response:

{
    "result" : [
        {
            "id": "e3b25351-0dd0-4679-90d6-fce9148b631b"
            "firstName": "Jane",
            "lastName": "Doe",
            "email": "[email protected]"
         }
    ],
    "pageSize": ???,
    "pageNumber": ???,
    "totalRecords": ???
}

References:

• https://www.lagomframework.com
• https://www.playframework.com
• https://stackoverflow.com/questions/tagged/lagom
• https://docs.microsoft.com/en-us/previous-versions/msp-n-p/jj554200(v=pandp.10)

Contributors:

Tarang Bhalodia

LinkedIn

Stack Overflow