JavaWorld has this trivial article on simulating multiple inheritance in Java software using delegation. What he explains in a big long-winded article with several examples, requires just one sentence to elucidate. It is an age old technique.

Create instances of objects (extend them if you need using inner classes) you wanted to inherit in the first place and delegate them the responsibility.

That's it!

This technique is widely used in all object oriented languages including but not limited to java software.