No Null Checks: Use firstNonNull method

When a reference is null I need to use a default value.
Use a common method to encapsulate selecting the first non null value.

In this example I am getting a package quantity for a product.  Since the data is not perfect, I use either the quantity, inner pack quantity or a default.  Since this method is in a domain object this is the only place this logic lives.

There are several firstNonNull methods you can use.  The one below is from apache commons and uses a variable argument parameter - so you can pick between many fields for the first non null value.  The one downside is that it returns null if all the values are null.  Be use to include a constant default in the group.

	public Integer getPackageQuantity() {
	return ObjectUtils.firstNonNull(quantity, innerPackQuantity, DEFAULT_QUANTITY);
	}

view raw firstNonNull1.java hosted with ❤ by GitHub

Another option is to roll your own utility method using lambdas.

	// Product class
	public Integer getPackageQuantity2() {
	return firstNonNull(quantity, innerPackQuantity, DEFAULT_QUANTITY);
	}
	// Utils class
	public static <T> T firstNonNull(T... args) {
	return Stream.of(args)
	.filter(Objects::nonNull)
	.findFirst()
	.get();
	}

view raw FirstNonNull2.java hosted with ❤ by GitHub

The findFirst function returns an instance of Optional. The terminating get method call is on the Optional and throws a NoSuchElementException if all the arguments are null.