Hacker News Reader

Comment by vishnugupta | Hacker News Reader

"foo".equals(bar) is definitely clear and shorter. However it is "clever" in the sense that it circumvents NPE with some sort of trick. Those who are new to Java don't get why and how it avoids NPE. To make matters worse they may even reverse the arguments for better readability, bar.equals("foo") which is a ticking NPE time bomb!

StringUtils.equals(a, b) on the other hand clearly states in its interface document that it is null safe and there's no NPE trap.

There, I said it :). That was my lengthy argument for using StringUtils.equals!

View on HN

Of course, StringUtils is not in the core API; the first idiom "foo".equals(bar) works in Java everywhere, StringUtils.equals("foo", bar) will only work in projects that pull in org.apache.commons. Personally I prefer using facilities in the core API over third party APIs, even if the third party API is included anyway for some essential function.

I've been coding in Java for over 10 years. If I ran across pretty much any project that wasn't including Apache commons I'd be startled. I get your point, but some libraries are in such common use that for all practical purposes I consider them part of the language API.

Understanding that there is the possibility of an NPE and reading enough of StringUtils contract to understand that it deals with requires approximately the same level of "cleverness" as understanding the "foo".equals(bar) behavior.

Code reviews should focus on more important things than this, IMO.

But the problem with your use of StringUtils, IMHO, is that it hides intent. If bar is expected to potentially be null, test for null. If bar should not be null, throw an NPE, and the fix the calling code.

Making code that shouldn't need to be "null safe" masks errors, and ultimately makes them harder to track down.

As you may have guessed from my previous comment, I hate it when people write "foo".equals(bar). This kind of a clever trick is an accident waiting to happen unless you're really, really ok with null being a valid value for bar (and more often than not, you're not ok with that). If null is not a valid value for bar, then it's better to catch it and deal with it as early as possible.

Reply on news.ycombinator.com