Filter Null Values from a List with Java8 Lambda

A common task with Java streams is to clean up the input data so later steps can work without thinking too hard. Likely the #1 most common cleanup step is to remove nulls from a Collection.

Streams make it easy:

myCollection.stream()
  .filter(Objects::nonNull)
  .do.what.you.need

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Compare with the classic approaches:

while(myCollection.remove(null));
// do what you need, but you better not need that original list, because it's gone...
myCollection.removeAll(Collections.singleton(null));
// do what you need, but you better not need that original list, because it's gone...

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Like the stream approach, these are short and sweet, but unlike the stream approach they modify the original list. The first example is also pretty slow.

I like the stream approach because I can chain additional tasks after the filter task, including map. sorted, reduce and more!. I find the traditional imperative iterative approach to be not only wordier, but conceptually harder to follow.

原文链接：Filter Null Values from a List with Java8 Lambda