Question

I am coding something like this:

List<Bean> beans = service.findBeans();
Collections.sort(beans, new BeanComparator());
return beans;

It works perfectly. What I am looking for is a shortcut to do this with just one line:

return somelibrary.Collections.sort(service.findBeans(), new BeanComparator());

Or:

return somelibrary.newList(service.findBeans(), new BeanComparator());

Note that it is required a mutable list.

Answer 1

This is one line:

List<Bean> beans = service.findBeans(); Collections.sort(beans, new BeanComparator()); return beans;

But more seriously, Java isn’t really the right language for one-liners. Also, just because something is a one-liner doesn’t mean that it is any better. For example, I was initially surprised to discover that this:

return condition ? a : b;

Creates a longer bytecode than

if( condition )
    return a;
else
    return b;

But that’s just how the language and compiler are.

If you insist on your one-liner, Guava‘s Ordering can do it:

return Ordering.from( new BeanComparator() ).sortedCopy( service.findBeans() );

The returned list is modifiable, serializable, and has random access.

Efficiency-wise I think there’s a bit of a waste in terms of overhead. And also you’re now dependent on a 3rd-party library. You’d be essentially using very powerful tools for a very simple task. It’s overkill if this is all you’re using it for.