Functional Programming in Java : Java Lambdas and Streams
Mastering Lambdas and Streams in Java (with lots of code examples)
What you will learn
Functional Interfaces - what they are and their relationship to lambda expressions.
Lambdas - anonymous inner class syntax versus lambda expressions.
Functional Interfaces from the API - sample code explaining Predicate/BiPredicate, Consumer/BiConsumer
Functional Interfaces from the API - sample code explaining Supplier, Function/BiFunction
Functional Interfaces from the API - sample code explaining UnaryOperator, BinaryOperator
Method References - their relationship with lambdas. Different types of method references explained with code - bound, unbound, static and constructor.
Method References - how the context helps in understanding them.
Streams - what they are, stream pipelines and stream laziness.
Streams - Terminal operations.
Streams - Terminal operations - reduce, collect() explained with code examples.
Streams - collect() using API collectors explained with code examples e.g. CollectorsDOTtoMap(), CollectorsDOTgroupingBy() and CollectorsDOTpartitioningBy()
Streams - Intermediate Operations explained with code examples e.g. filter(), distinct(), limit(), map(), flatMap() and sorted().
Streams - stateful and short-circuiting intermediate operations explained.
Streams - Primitive Streams - how to create them, what their API's look like and how to map between them.
Streams - mapping between Object streams and primitive streams and vice versa.
Optionals - what they are and why they are useful. Sample code demonstrating their use.
Parallel Streams - how to create them. Sequential versus parallel stream processing.
Why take this course?
IMPORTANT - My advanced Java course: Java 21, Java 17, Java 11, Advanced Java 8 (1Z0-829,1Z0-819,1Z0-809), contains this course as a subset. My advanced Java course contains an extra 12 hours of content and is worth checking out before investing in this this course (as it is, in my opinion, better value for money).
UPDATE February 2023 - streams assignment added!
UPDATE April 2022 - lambdas/method references assignment added!
This course is a systematic approach to explaining in both notes format and code examples, lambda expressions and streams in Java. All the code samples are included.
Topics include:
Lambdas:
Functional Interfaces
Lambdas and their relationship to Functional Interfaces
Lambdas in code using a custom Functional Interface
Lambdas in code using the pre-defined API Functional Interfaces:
Predicate/BiPredicate
Supplier
Consumer/BiConsumer
Function/BiFunction
UnaryOperator and BinaryOperator
final and "effectively final"
Method References:
bound
unbound
static
constructor
context and it's effect in understanding method references
Streams:
Pipelines
Laziness
Creating streams
Terminal operations:
reduce()
collect()
Collectors.toMap()
Collectors.groupingBy()
Collectors.partitioningBy()
Intermediate operations:
filter(), distinct(), limit()
map(), flatMap(), sorted()
Primitive streams:
Creating
API
Functional Interfaces
Mapping between primitive streams
Mapping between primitive streams and Object streams and vice versa
Optionals
Parallel streams
This course is geared towards Java Certification i.e. the Predicate lambda sections would suit Java 8 OCA (1Z0-808). The remaining lambda sections and the streams sections would suit both Java 8 OCP (1Z0-809) and Java 11 (1Z0-819). This course explains the concepts through small, simple, targeted code examples.
For those who don't know me, my "Complete Java 8 OCA (1Z0-808) Java Certification Course" is, at the time of writing, the highest rated Java 8 OCA course on Udemy. I am a lecturer since 2002 and have taught the OCA and OCP syllabii since 2013 on behalf of a highly regarded software company. On completion of the courses with me, graduates then face the company's own internal Java Certification exam (similar in style to Oracle's). I have no visibility into the questions they will face. It is a 3 hour long intensive exam. The company are delighted with the pass rate (100% since year 1).
I love teaching and this course has all my experience in explaining lambdas and streams in Java. I am delighted that Enthuware (the excellent Java certification training tool), have, in their explanations, linked to my YouTube channel.
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