How to make a chained object null-safe for iteration

Asked Mar 25 '18 at 20:47

Active Mar 25 '18 at 20:53

Viewed 135 times

New to Java.

I'm trying to avoid NullPointerException when iterating over a list. CollectionUtils.emptyIfNull() helps, but not for a chained object.

For example:

for (MyObject myObj : CollectionUtils.emptyIfNull(
    result.item.getMyObject().getObjects())) {
    // do stuff
    }

I have no control over MyObject because I wrote a client that consumes this as a dependency. Any of these attributes could be null, and emptyIfNull() only protects against getObjects() returning null.

Is there a way to apply emptyIfNull() or something similar to the entire chain of calls?

Thanks for the help!

asked Mar 25 '18 at 20:47

Bowser

Can you use the `Optional`? – zlakad Mar 25 '18 at 20:50
Use `Optional`. And `Stream`. And **not** an ancient and outdated library - especially if you're new to Java! – Boris the Spider Mar 25 '18 at 20:50
maybe something like `for (MyObject myObj : Optional.ofNullable(result) .map(e -> e.item) .map(e -> e.getMyObject()) .map(e -> e.getObjects()) .orElse(Collections.emptyList())` – Ousmane D. Mar 25 '18 at 20:53

How to make a chained object null-safe for iteration

0 Answers0