Is there a shortcut to execute something only if its not null?

Question

I find myself constantly writing this statement

MyObject myObject = something.getThatObject();
if( myObject !=null &&
    myObject .someBooleanFunction()){

}

in order to prevent a null pointer exception. Is there a shortcut to this in Java? I'm thinking like myObject..someBooleanFunction()?

I don't think there is a way to make it shorter in Java but there are languages you can run on the JVM that support this kind of functionality. Groovy is fine example with its ["Elvis" and safe navigation operators](http://groovy.codehaus.org/Operators#Operators-ElvisOperator(?:)) So much for language features. As for making it shorter, take a look at `Optional` idioms in either Guava or Scala libraries. I believe Scala also has a neat syntax for it but I'm not familiar with it. — toniedzwiedz, May 29 '14 at 18:58

Joop Eggen · Accepted Answer · 2014-05-29T21:11:20.293

6

In Java 8:

static <T> boolean notNull(Supplier<T> getter, Predicate<T> tester) {
    T x = getter.get();
    return x != null && tester.test(x);
}

    if (notNull(something::getThatObject, MyObject::someBooleanFunction)) {
        ...
    }

If this style is new to the readers, one should keep in mind, that full functional programming is a bit nicer.

edited May 29 '14 at 21:11

answered May 29 '14 at 20:06

Joop Eggen

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score 4 · Answer 2 · answered May 29 '14 at 18:59

4

Well Java 8 has got something called Optional. More details are at : http://www.oracle.com/technetwork/articles/java/java8-optional-2175753.html

answered May 29 '14 at 18:59

jatanp

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score 1 · Answer 3 · answered May 29 '14 at 18:55

1

No, I am fairly sure that there is no way to do it any shorter than what you have.

answered May 29 '14 at 18:55

Epiglottal Axolotl

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score 0 · Answer 4 · edited May 23 '17 at 11:44

No if it is an object. String has isEmpty() but there is no built in way to check if an object is null other than what you have. This closed question has some comments that may help: why there is no isNull method in java object class

You could write your own in the class that would check null and your other method but it would have to be static or else you would run into your null pointer problem.

Is there a shortcut to execute something only if its not null?

4 Answers4