compare and sort different type of objects using java Collections

Question

How to compare and sort different type of objects using java Collections .Below is the use case: For example DOG,MAN,TREE, COMPUTER,MACHINE - all these different objects has

Answer 1

If all your classes implement a Living interface defined as it follows (always a good idea in Java):

public interface Living {
    int getLifeTime();
}

you can sort your collections of Living objects by using the lambdaj library as it follows:

List sortedLivings = sort(livings, on(Alive.class).getLifeTime());