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How to implement real-time data updates using WebSocket in Kotlin Android

How to implement real-time data updates using WebSocket in Kotlin Android.

Here's a detailed step-by-step tutorial on how to implement real-time data updates using WebSocket in Kotlin Android.

Step 1: Add WebSocket dependency​

To get started, you need to add the WebSocket dependency to your project. Open your app-level build.gradle file and add the following line in the dependencies block:

implementation "org.java-websocket:Java-WebSocket:1.5.1"

Step 2: Create WebSocket client​

Next, you need to create a WebSocket client to establish a connection with the server. Create a new Kotlin class called WebSocketClient.kt and add the following code:

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

class MyWebSocketClient(serverUri: URI) : WebSocketClient(serverUri) {
    override fun onOpen(handshakedata: ServerHandshake) {
        // Connection established
        // You can send any initial messages here
    }

    override fun onClose(code: Int, reason: String, remote: Boolean) {
        // Connection closed
    }

    override fun onMessage(message: String) {
        // Handle incoming messages from the server
    }

    override fun onError(ex: Exception) {
        // Handle any errors
    }
}

Step 3: Establish WebSocket connection​

In your activity or fragment where you want to establish the WebSocket connection, create an instance of the MyWebSocketClient class and connect to the server. Add the following code:

import java.net.URI

val serverUri = URI("wss://your-websocket-server.com")
val webSocketClient = MyWebSocketClient(serverUri)
webSocketClient.connect()

Make sure to replace "wss://your-websocket-server.com" with the actual WebSocket server URL.

Step 4: Send and receive messages​

To send and receive messages over the WebSocket connection, you can use the methods provided by the WebSocketClient class. Here are some examples:

Sending a message:

webSocketClient.send("Hello server!")

Receiving a message:

webSocketClient.onMessage = { message ->
    // Handle incoming message from the server
}

Step 5: Close the WebSocket connection​

When you're done with the WebSocket connection, make sure to close it to free up resources. You can do this by calling the close() method on the WebSocketClient instance:

webSocketClient.close()

That's it! You have successfully implemented real-time data updates using WebSocket in Kotlin Android. You can now send and receive real-time messages from the server.

Remember to handle errors, implement any necessary authentication or authorization, and handle disconnections gracefully in your application.

I hope you find this tutorial helpful.