How to send and receive messages using WebSocket in Kotlin Android

How to send and receive messages using WebSocket in Kotlin Android.

Here's a step-by-step tutorial on how to send and receive messages using WebSocket in Kotlin Android:

Add the necessary dependencies:
- Open your project's build.gradle file and add the following dependency inside the dependencies block:
```
implementation 'org.java-websocket:Java-WebSocket:1.4.1'
```

Create a WebSocket client class:

Create a new Kotlin class called WebSocketClient.kt.

Import the necessary classes:

import org.java_websocket.client.WebSocketClient
import org.java_websocket.handshake.ServerHandshake
import java.net.URI

Declare a class that extends WebSocketClient:

class MyWebSocketClient(serverUri: URI) : WebSocketClient(serverUri) {
    // WebSocket event callbacks
    override fun onOpen(handshakedata: ServerHandshake?) {
        // Called when the WebSocket connection is established
    }

    override fun onClose(code: Int, reason: String?, remote: Boolean) {
        // Called when the WebSocket connection is closed
    }

    override fun onMessage(message: String?) {
        // Called when a message is received from the WebSocket server
    }

    override fun onError(ex: Exception?) {
        // Called when an error occurs in the WebSocket connection
    }
}

Initialize and connect the WebSocket client:
- In your activity or fragment, create an instance of the WebSocket client and connect to the server:
```
val serverUri = URI("wss://your-websocket-server-url")
val webSocketClient = MyWebSocketClient(serverUri)
webSocketClient.connect()
```
Implement sending messages:
- To send a message to the WebSocket server, use the send method of the WebSocket client:
```
val message = "Hello, server!"
webSocketClient.send(message)
```

Implement receiving messages:

To receive messages from the WebSocket server, handle the onMessage callback in your WebSocket client class:

override fun onMessage(message: String?) {
    // Handle the received message
    if (message != null) {
        // Do something with the message
    }
}

Handle WebSocket connection events:
- In your WebSocket client class, you can handle the onOpen, onClose, and onError callbacks to perform actions based on the WebSocket connection status.

And that's it! You now know how to send and receive messages using WebSocket in Kotlin Android.