How to implement Java 8 Stream API using Java 7 or older?

Question

I was asked this question in a job interview (Microsoft).
methods to implement for example:
.stream(), .filter(), .map() , flatMap() , min() , count() , reduce() , groupBy()
etc

It's quite an open question but I think is an interesting one.

Thanks

Answer 1

One way to get an ability to use StreamAPI in your Java7 and Java6 projects add a streamsupport library https://github.com/streamsupport/streamsupport Streamsupport is a backport of the Java 8 java.util.function (functional interfaces) and java.util.stream (streams) API for users of Java 6 or 7