I think HTML5 has incorporated Java.
If so, that should do something for security...
That's not accurate. Java is a standalone programming language that is not built into HTML 5 at all. People often confuse Java with JavaScript which are completely unrelated except for some common syntax. JavaScript is the primary language used by web browsers for interactive web pages. Java can be used for this with a special plugin (often buggy and insecure) but it is much less common. If you do have Java on your computer you must, must, must keep it up to date with the latest updates and run it with the default security restrictions.