Messaging demo

Build and run (Docker)

• to build the project, run ./gradlew build from the top level folder
• then run it with docker-compose up
• Once it's running, you can test the application through Swagger-UI. (You may be asked by Swagger to set base path, in that case enter http://localhost:8080/ in the dialog)

Description

• To create a new user, you can post to the /users endpoint a json object like the following

{
 "nickName": "nickname of the user"
}

If the request succeeds, the service answers with status code 200, and a representation of the newly created user.

{
    "id": "33f336a366794522ab0c237cc64edddb",
    "nickName": "string"
}

• To send a new message, you can post to the messages endpoint a json object like the following

{
  "message": "the text that I want to send",
  "receiverId": "idOfTheReceiver"
}

the id of the user that is sending the message should be passed in the userid header.
If the request succeeds, the service will return status code 200, and a json representation of the newly created message

{
  "id": 123123123,
  "message": "the text that I want to send",
  "receiver": {
    "id": "idOfTheReceiver",
    "nickName": "Reece"
  },
  "sender": {
    "id": "idOfTheSender",
    "nickName": "Sandy"
  }
}

• To view all the messages that you received, you can make a get request to the /messages/received endpoint.
  The id of the user that is sending the message should be passed in the userid header.
  Some optional query parameters can be passed:
  • senderId : the ID of the sender, to restrict the answer to the messages sent by a specific user
  • limit : the maximum amount of messages to be returned (if not specified, the default value is 50)
  • startingId : the minimum allowed ID of the messages that will be returned (The default value is -1) The messages will be returned in a json object like the following

{
  "hasMore": false,
  "messages": [
    {
      "id": 0,
      "message": "some text",
      "receiver": {
        "id": "123",
        "nickName": "Richie"
      },
      "sender": {
        "id": "456",
        "nickName": "Sam"
      }
    }
  ]
}

The messages are sorted by id (decreasing), or rather, by creation date (newest first).
The field hasMore specifies whether there are more messages that can be loaded but have been filtered out (because the limit was hit)
In case hasMore is true, you can make a new request specifying the last message's id asstartingId to load the next "page" of results.

• To view all the messages that you sent, you can make a get request to the /messages/sent endpoint.
  As usual The id of the user that is sending the message should be passed in the userid header.
  Some optional query parameters can be passed, like in /messages/received:

  • limit : the maximum amount of messages to be returned (if not specified, the default value is 50)
  • startingId : the minimum allowed ID of the messages that will be returned (The default value is -1) The messages will be returned with the same json structure as /messages/received

• The endpoints handle some incorrect input, and answer with status code 400 and a descriptive error message in the following cases:

  • you try to create an user, and an user with the same nickname already exists
  • you don't pass the userid header when required
  • the user identified by userid or the one in the senderId parameter does not exist
  • you try send a message to yourself,
  • you try to get the received messages, and you specify your user id in the senderId parameter

• When a message gets created, a message is put on a RabbitMQ queue