Is there a way to avoid null check before the for-each loop iteration starts?

public <T extends Iterable> T nullGuard(T item) {
  if (item == null) {
    return Collections.EmptyList;
  } else {
    return item;
  }
}

or, if saving lines of text is a priority (it shouldn't be)

public <T extends Iterable> T nullGuard(T item) {
  return (item == null) ? Collections.EmptyList : item;
}

would allow you to write

for (Object obj : nullGuard(list)) {
  ...
}

Of course, this really just moves the complexity elsewhere.

It's already 2017, and you can now use Apache Commons Collections4

The usage:

for(Object obj : CollectionUtils.emptyIfNull(list1)){
    // Do your stuff
}

If possible, you should design your code such that the collections aren't null in the first place.

null collections are bad practice (for this reason); you should use empty collections instead. (eg, Collections.emptyList())

Alternatively, you could make a wrapper class that implements Iterable and takes a collections, and handles a null collection.
You could then write foreach(T obj : new Nullable<T>(list1))

I guess the right answer is that: there is no way to make it shorter. There are some techniques such as the ones in the comments, but I don't see myself using them. I think it's better to write a "if" block than to use those techniques. and yes.. before anybody mentions it yet again :) "ideally" the code should be desgined such that list should never be a null