#STREAMS IN JAVA HOW TO#
#STREAMS IN JAVA CODE#

#STREAMS IN JAVA HOW TO#

* Java program to demonstrate how to use Java 8 Stream API with simple Now let's see the code, and then we will talk about each example. Once you know the basics, you can also apply it to other Collection classes, like HashSet or HashMap. Since the collection is going to be the starting point for a stream, I have used a ListВ for all my examples. In fact, stream API is a handy abstraction for working with aggregated data, particularly when we need to perform multiple actions, such as transforming the content, apply some filters and perhaps group them by a property. By the way, you can get Stream not just from the CollectionВ but from other sources like Random Number generatorВ and FileInputStream. operations on streams don't affect the collection from which streams are obtained. The good thing about Streams is that they leave source collection intact, i.e. Terminal operations are used to produce a result, and after that, you cannot reuse them. This stream provides an elegant lazy evaluation of an expression, and it also supports intermediate and terminal operations. By the way, this stream is a bit different than your Java IO streams, e.g. You can use Streams to do a lot of things in Java 8. How to use Stream API in Java 8? Examples You can read more about that in this excellent From Collections to Streams in Java 8 Using Lambda ExpressionsВ course on Pluralsight. Remember filter()В is a tricky method, it does not filter element from the original collection instead, it selects item which satisfies criterion and returns them in new Collection. All Strings which are empty are counted by the count()В method, which is a terminal operation.ДЄfter this line, you can not call any method on this Stream.

#STREAMS IN JAVA CODE#

This code will go to the test()В method of Predicate and will be applied to each element during internal iteration. Here we can define code to specify a condition. Since the В is a functional interface ( an interface with just one abstract method), we can pass lambda expression instead of an instance of the Predicate interface. In second-line strList.stream()В returns a Stream, and then we use the filter()В method, which accepts a Predicate.

This is an excellent example to demonstrate how you can filter specific objects from Collection and create a subset of elements that satisfy the given criterion. You can also check out a comprehensive online course like The Java MasterClass to learn them in depth along with other Java 8 changes. This is by no means a complete set of examples you need to master Java 8 Stream API, but it will introduce key functions and encourage you to explore by yourself by reading Java documentation and trying them. Some of the most common things we do with Streams are filtering a collection, applying map and reduce function on all elements of the collection, and taking advantage of lazy evaluation, built-in parallelism via parallelStream().

Streams are one of the most important additions on JDK, it allows you to leverage other changes like lambda expression, method reference, functional interface, and internal iteration introduced via the forEach() method. In this Java 8 tutorial, I have shared some simple examples of package, which you can use in your day-to-day Java programming tasks. I learned that way, and that's what prompts me to write this article. In my opinion, the best way to learn any new feature or functionality is by writing short examples and understanding them in depth. Since then, a lot of Java developers are trying their hands to learn those significant changes like lambda expression, method reference, new Date and Time classes, and, more importantly, Stream API for bulk data operations.

The most significant change it brings in the mindset of Java developers was to think functional and supported that by providing critical features like lambda expression and Stream API, which takes advantage of parallel processing and functional operations like filter, map, flatMap, etc. It not only provided some useful methods but totally changed the way you write programs in Java. Import java.io.The Java 8 release of Java Programming language was a game-changer version.

Streams in java