Java 8 workshop blog post

finn-no · Feb 16, 2015 · 1dec0b8 · 1dec0b8
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diff --git a/_posts/2015-02-16-java-8-workshop-at-finnno.md b/_posts/2015-02-16-java-8-workshop-at-finnno.md
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+---
+layout: post
+comments: true
+date: 2015-02-16 08:50:16+0100
+authors: Sjur Millidahl
+title: "Java 8 workshop at Finn.no"
+tags:
+- java
+- java8
+- functional
+- lambda
+- workshop
+---
+
+<figure>
+  <img src="/images/2015-02-06-java-8-workshopp-at-finnno/DSC_0091.JPG" alt="Pondering on the right lambda for the job" />
+  <figcaption>Pondering on the right lambda for the job</figcaption>
+</figure>
+
+With Java 8 comes a whole new set of language features. It even challenges the imperative coding-style of the Java programmer.
+
+Java is a core language in Finn.no. More and more of our java-modules are being built with Java 8, adopting new features of the language.
+A workshop was warranted, with the goal of bringing every developer up to speed on the functional paradigm of Java 8.
+
+In Finn.no, we want programmers to do stuff like this
+
+```java
+db.fetchLastDayAds()
+  .stream()
+  .filter(ad -> "bap-webstore".equals(ad.getAdType()))
+  .flatMap(ad -> ad.getContacts().stream())
+  .distinct()
+  .flatMap(per -> 
+    Optional.ofNullable(contact.getEmail()).map(Stream::of)
+    .orElseGet(Stream::empty))
+  .peek(contact -> LOG.trace("Sending notification to "+per))
+  .forEach(this::sendNotification);
+```
+
+While avoiding stuff like this
+
+
+```java
+IntStream.iterate(0, i -> (i + 1) % 2)
+         .parallel()
+         .distinct()
+         .limit(10)
+         .forEach(System.out::println);
+```
+(Locking up all cores on a CPU is bad, and should only be done when the machine is right about to become self-aware and turn against you.)
+
+<figure>
+  <img src="/images/2015-02-06-java-8-workshopp-at-finnno/DSC_0092.JPG" alt="Several lambda-arrows pointing in the right direction here"/>
+  <figcaption>Several lambda-arrows pointing in the right direction here</figcaption>
+</figure>
+
+We split the workshop into two half days. The first day was dedicated to streams and lambdas. Everyone seemed keen on getting those tests green (a rhyme!). 
+
+Day 2 we raised the bar with Optional<T> and our in-house version of Either<L,R>. With these structures, much more code can be written functionally in a world where values might not exist (be null), and things may go wrong (throw exceptions). 
+
+<figure>
+  <img src="/images/2015-02-06-java-8-workshopp-at-finnno/DSC_0095.JPG" alt ="We need power.. lots of power!" />
+  <figcaption>We need power.. lots of power!</figcaption>
+</figure>
+
+Both the word "monad" and the phrase "monadic domain" was uttered several times, but we still saw very few making the swoooosh-sound while flying a hand over their head (the internationally recognized sign of communicating that a topic is beyond mental capacity).
+
+This might mean that the timing was good, and developers are interested in the new features of Java 8.
+
+You may [checkout the project and do the tasks yourself](https://github.com/mariatsji/java8-workshop.git), by making the failing tests green
+
diff --git a/images/2015-02-06-java-8-workshopp-at-finnno/DSC_0091.JPG b/images/2015-02-06-java-8-workshopp-at-finnno/DSC_0091.JPG
diff --git a/images/2015-02-06-java-8-workshopp-at-finnno/DSC_0092.JPG b/images/2015-02-06-java-8-workshopp-at-finnno/DSC_0092.JPG
diff --git a/images/2015-02-06-java-8-workshopp-at-finnno/DSC_0095.JPG b/images/2015-02-06-java-8-workshopp-at-finnno/DSC_0095.JPG