Java8 Lambda - Stream INSTA

Get Started with lambda and stream. New astonishing features of Java 8. It's inspired by java 8 kata.

Usage

Run the tests

You can run tests from your IDE or command line if you like. If you are using an IDE, right click on the test method and click Run foobar(). If you prefer command line, follow below.

$ pwd
/path/to/java8-code-kata

$ ./mvnw install -Dmaven.test.skip=true

$ ./mvnw test -Dtest=Exercise1Test#findRichCustomers -pl stream-api

Edit unit tests.

To successfully pass the tests, you'll need to edit the test itself. You can see where you need to edit.

@Easy @Test
public void simpleAddition() {
    /**
     * Get an addition result of 1 and 2 by using an operator "+".
     */
    Integer added = null;

    assertThat(added, is(3));
}

Here is a sample answer.

@Easy @Test
public void simpleAddition() {
    /**
     * Get an addition result of 1 and 2 by using an operator "+".
     */
    Integer added = 1 + 2;

    assertThat(added, is(3));
}

Most tests are annotated with @Easy which means those tests only requires basic knowledge.

Tests annotated with @Difficult are more difficult. 😁

Modules

Playground

Use in conference session only

stream-api

Exercise1Test.java

Stream#filter and Stream#map

Exercise2Test.java

Stream#sorted, Stream#distinct, Stream#limit and Stream#flatMap

Exercise3Test.java

Stream#count, Stream#max and Stream#min

Exercise4Test.java

Stream#findFirst, Stream#allMatch, Stream#anyMatch and Stream#noneMatch

Exercise5Test.java

Stream#collect and Collectors

Exercise6Test.java

Stream#of and Stream#iterate

Exercise7Test.java

IntStream, LongStream and DoubleStream

Exercise8Test.java

Advanced problems

Exercise9Test.java

Collector

collection-interfaces

Exercise1Test.java

Iterable#forEach, Collection#removeIf, List#replaceAll, List#sort, Collection#stream and Collection#parallelStream

Exercise2Test.java

Map#getOrDefault, Map#putIfAbsent, Map#merge and Map#computeIfPresent

jfitoussi / java8-lambda-stream-insta