Java EE 7 Application Developer — Question 5

Which statement is true about the relationship between HTTP and WebSockets?

Answer options

• A. A WebSocket connection is a bi-directional HTTP session with message-handling support.
• B. A WebSocket connection is initialized with an HTTP handshake.
• C. A WebSocket connection can be initialized by either client or server.
• D. A WebSocket connection uses HTTP protocol to exchange data with the browser.

Correct answer: D

Explanation

The correct answer is D because WebSocket connections begin with an HTTP handshake, establishing an initial connection before upgrading to a full-duplex communication channel. Option A is incorrect as it misrepresents the nature of the connection; it is not just a session but an upgrade. Option C is misleading because the client must initiate the handshake, while option B is incomplete as it doesn't mention the upgrade process that follows the handshake.