Can I trust jmeter testing result?

I am using JMeter to test my WebSocket connection.

I using HashMap to keep my WebSocket connections.

In my foreach I will call WebSocketHandler.sendMessage();

I saw the System.currentTimeMilli when I iterator this map it will take me 16-32ms in size 200.

It's very quickly. but In JMeter tester say they need to 3000ms to get the message from spring-MVC.

I using thread to make it quickly but in JMeter does have any change.

How can I make tomcat websocket quickly as soon as my for each method?

My JMeter script is

make connection 200. and send it a message. receive my response and counting average time.