Answer to Question #243668 in Algorithms for Hafeni

Question

Problem

This problem is related to the virtual learning environment application discussed in one theory session and a few practicals. In

this problem, you are tasked with creating and updating learner profiles, a particular type of user. As well, given a learner profile,

we would like to retrieve the learning materials in the form of topics. Note that the learning materials for a given course will differ

from one learner profile to another. For example, for a course "Distributed Systems and Applications", the learning materials for

a learner with a weak background in "Programming" compared o another learner profile with a stronger background in

programming.

Your task is to:

1. Provide a description in OpenAPI of the API that allows for communication between a client and a service for the

functionalities discussed above;

2. Implement a corresponding client and a service.

Answer 1

1.

{
  "description": "user to add to the system",
  "content": {
    "application/json": {
      "schema": {
        "$ref": "#/components/schemas/User"
      },
      "examples": {
          "user" : {
            "summary": "User Example", 
            "externalValue": "http://foo.bar/examples/user-example.json"
          } 
        }
    },
    "application/xml": {
      "schema": {
        "$ref": "#/components/schemas/User"
      },
      "examples": {
          "user" : {
            "summary": "User example in XML",
            "externalValue": "http://foo.bar/examples/user-example.xml"
          }
        }
    },
    "text/plain": {
      "examples": {
        "user" : {
            "summary": "User example in Plain text",
            "externalValue": "http://foo.bar/examples/user-example.txt" 
        }
      } 
    },
    "*/*": {
      "examples": {
        "user" : {
            "summary": "User example in other format",
            "externalValue": "http://foo.bar/examples/user-example.whatever"
        }
      }
    }
  }
}
{
  "description": "user to add to the system",
  "content": {
    "text/plain": {
      "schema": {
        "type": "array",
        "items": {
          "type": "string"
        }
      }
    }
  }
}

2.

try {
  // create a socket
  String serverHost = ... ;   // server hostname or IP adress
  int serverPort = ... ;      // server port number
  Socket socket = new Socket(serverHost, serverPort)
  
  // get the streams 
  OutputStream sockOut = socket.getOutputStream();
  InputStream  sockIn = socket.getInputStream();

  // Communicate:
  
  // send a request to the server
  sockOut.write(...);
    ...

  // get the response 
  sockIn.read(...);
   ...

  // communication completed  
  // close streams and the socket
  sockOut.close();
  sockIn.close();
  socket.close();  

} catch (UnknownHostException exc) {
    // unknown host
} catch (SocketException exc) {
    // socket-related exceptions
} catch (IOException exc) {
    // input-output exceptions
}