jvm - Inlining in Java

Question

In C++ I can declare a method "inline" and the compiler is likely to inline it. As far as I understand there is no such keyword in Java.

Inlining is done if the JVM decides to do so? Can I influence this decision somehow?

Answer 1

A couple of the other answers have suggested that only final methods can be inlined - this is not true, as HotSpot is smart enough to be able to inline non-final methods so long as they haven't been overridden yet. When a class is loaded which overrides the method, it can undo its optimisation. Obviously making the method final mean that's never required...

Basically let the JVM do its job - it's likely to be a lot better at working out where to inline than you are.

Do you have a situation where you're convinced that the JVM isn't doing a good job? Assuming you're using HotSpot, have you tried using the server version instead of client? That can make a huge difference.