echoclient.html

  
 <!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Echo Demo</title>
</head>
<body>
<h1>Echo Demo</h1>
<input type="text" id="message">
<button type="button" onclick="sendMessage()">Send</button>
<div id="echo"></div>
<a href="/">Back</a>
<script>
    var ws = new WebSocket("/echo")

    ws.onopen = function (event) {
        alert("WebSocket successfully established")
    }

    function sendMessage(){
        var message = document.getElementById("message").value
        ws.send(message)
    }

    ws.onmessage = function (message) {
        echo.innerHTML += "<p>" + message.data + "</p>"
    }

</script>
</body>
</html>