index.html

<html>

<body style="margin: 35px">
<form>
    <textarea id="messageField" rows="4" cols="50"></textarea>
    <input onclick="sendMsg();" value="send" type="button">
</form>

<div id="msg-box" style="width:500px; height: 400px; background: #eee; overflow:auto;"></div>


<script>
    var webSocket = new WebSocket("ws://localhost:8080/");
    var msgField = document.getElementById("messageField");
    var divMsg = document.getElementById("msg-box");
    
    messageField.value='>1\nAACCGGTTTAAA\n>2\nAACCGGTTCAAA';

    function sendMsg() {
        var msgToSend = msgField.value;
        webSocket.send(msgToSend);
//        divMsg.innerHTML += "<div style='color:red'>Client> " + msgToSend +
//                            "</div>"
        msgField.value = "";
    }

    webSocket.onmessage = function(message) {
//                divMsg.innerHTML += "Server> : " + message.data;
				divMsg.innerHTML += message.data + "\n";
            }

    webSocket.onopen = function() {
        console.log("connection opened");
    };

    webSocket.onclose = function() {
        console.log("connection closed");
    };

    webSocket.onerror = function wserror(message) {
        console.log("error: " + message);
    }


</script>
</body>
</html>