Live coding java 8 urs peter

Live Coding:

By Urs Peter

[email protected] @urs_peter

New Features of Java 8

•  JSR 335 Lambda Expressions and Virtual Extension Methods

•  JSR 308 AnnotaJons on Java Types Map<@NonNull String, @NonEmpty List<@Readonly Document>> files; !

•  JSR 310 Date and Time API OffsetDateTime now = OffsetDateTime.now(); System.out.println(now.format(DateTimeFormatter.ISO_DATE)); !









FuncAonal Programming

MulAple Inheritance of Behaviour

Let’s Dive into Java 8!

What will change for you?

FuncJonal programming becomes mainstream!

How to get funcJonal

•  Change the way you look at programming logic: –  Think in terms of transforming data or input/output …instead manipulaJng state

– Make immutable programming the default, mutable programming the excepJon

–  FuncJonal programming implies programming on a higher abstracAon level

How to get funcJonal

•  Start using higher order funcJons (filter(), map() etc.) in CollecJons/Streams – Whenever you use a for loop try to come up with a funcJonal alternaJve

•  Use Lambda’s in your own so]ware structures –  E.g. Use Lambda’s instead of a Template or Strategy pa^ern

•  Learn to read Javadoc for Lambda’s

When to apply Virtual Extension Methods

•  Use Virtual Extension Methods to make new addiJons to your

API backwards compaJble

•  Add useful default implementaJons to your interfaces –  E.g. Comparator: boolean gt(T other), boolean lt(T other) !

•  Bundle cross-‐cuang behaviour in interfaces with default methods –  E.g. Logging

Q & A

Urs Peter

[email protected] @urs_peter

Live coding java 8 urs peter

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