Merge branch '89-code-coffee-concurrent-code' into 'master'

Resolve "Code & coffee concurrent code"

Closes #89

See merge request !69

.gitlab-ci.yml

@@ -28,3 +28,4 @@ include:
   - local: "/fizz-buzz/.gitlab-ci.yml"
   - local: "/leap-years/.gitlab-ci.yml"
   - local: "/employee-report/.gitlab-ci.yml"
+  - local: "/java-concurrence/.gitlab-ci.yml"

.gitlab-common-ci.yml

@@ -9,13 +9,26 @@ cache:
 stages:
   - build
 
-.java:
+.java-parent:
   image: maven:3.6.3-jdk-14
   stage: build
   tags:
     - docker
   before_script:
     - cd $PROJECT_FOLDER
+
+.java-no-jacoco:
+  extends: .java-parent
+  script:
+    - mvn $MAVEN_CLI_OPTS clean package
+  artifacts:
+    reports:
+      junit: $PROJECT_FOLDER/target/surefire-reports/TEST-*.xml
+    name: "$PROJECT_FOLDER-report"
+    expire_in: 1 day
+
+.java:
+  extends: .java-parent
   script:
     - mvn $MAVEN_CLI_OPTS clean package
     - awk -F"," '{ branches += $4 + $5 + $6 + $7; covered += $5 + $7 } END { print covered, "/", branches, "branches covered"; print 100*covered/branches, "%covered" }' target/site/jacoco/jacoco.csv

java-concurrence/.gitlab-ci.yml

+package-java-concurrence:
+  variables:
+    PROJECT_FOLDER: "java-concurrence"
+  extends: .java-no-jacoco
+  only:
+    refs:
+      - master
+      - merge_requests
+    changes:
+      - ".gitlab-common-ci.yml"
+      - "java-concurrence/**/*"

java-concurrence/pom.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <version>1.0.0</version>
+    <groupId>fr.ippon.kata</groupId>
+    <artifactId>java-parent</artifactId>
+    <relativePath>../java-parent</relativePath>
+  </parent>
+
+  <version>1.0.0-SNAPSHOT</version>
+  <artifactId>java-concurrence</artifactId>
+
+  <name>JavaConcurrence</name>
+
+  <developers>
+    <developer>
+      <email>arey@ippon.fr</email>
+      <name>Anthony REY</name>
+    </developer>
+    <developer>
+      <email>cdamon@ippon.fr</email>
+      <name>Colin DAMON</name>
+    </developer>
+  </developers>
+</project>

java-concurrence/readme.md

+# Code && coffee : Concurrence en java
+
+Code & coffee sur la concurrence en Java
+
+-   **Auteurs** : Anthony REY et Colin DAMON
+-   **Date** : 17/03/2021
+-   **Langage** : Java
+-   **Niveau** : Enervé
+-   **Replay** : TODO

java-concurrence/src/test/java/fr/craft/kata/ThreadingTest.java

+package fr.craft.kata;
+
+import static org.assertj.core.api.Assertions.*;
+
+import java.text.SimpleDateFormat;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.GregorianCalendar;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
+import org.junit.jupiter.api.Test;
+
+public class ThreadingTest {
+
+  @Test
+  void shouldStopThread() throws InterruptedException {
+    StopableThread process = new StopableThread();
+    Thread thread = new Thread(process);
+    thread.start();
+
+    Thread.sleep(100);
+    process.stop();
+
+    Thread.sleep(200);
+
+    assertThat(thread.isAlive()).isFalse();
+  }
+
+  @Test
+  void shouldPlayWithThreads() throws InterruptedException {
+    ExecutorService executor = Executors.newFixedThreadPool(5);
+
+    AtomicInteger counter = new AtomicInteger();
+    Set<Future<Integer>> results = new HashSet<>();
+    for (int i = 0; i < 100; i++) {
+      results.add(executor.submit(() -> counter.incrementAndGet()));
+    }
+
+    executor.shutdown();
+    executor.awaitTermination(1, TimeUnit.SECONDS);
+
+    assertThat(results).extracting(result -> result.get()).hasSize(100);
+  }
+
+  @Test
+  void shouldHaveThreadSafeCollection() throws InterruptedException {
+    ExecutorService executor = Executors.newFixedThreadPool(5);
+
+    Collection<UUID> ids = Collections.newSetFromMap(new ConcurrentHashMap<>());
+    for (int i = 0; i < 100; i++) {
+      executor.submit(() -> ids.add(UUID.randomUUID()));
+    }
+
+    executor.shutdown();
+    executor.awaitTermination(1, TimeUnit.SECONDS);
+
+    assertThat(ids).hasSize(100);
+  }
+
+  @Test
+  void shouldHaveOldDates() throws InterruptedException {
+    ExecutorService executor = Executors.newFixedThreadPool(5);
+
+    Collection<Integer> days = Collections.newSetFromMap(new ConcurrentHashMap<>());
+    for (int day = 0; day < 31; day++) {
+      GregorianCalendar date = new GregorianCalendar(2021, 00, day);
+
+      executor.submit(
+        () -> {
+          SimpleDateFormat format = new SimpleDateFormat("dd");
+
+          return days.add(Integer.parseInt(format.format(date.getTime())));
+        }
+      );
+    }
+
+    executor.shutdown();
+    executor.awaitTermination(1, TimeUnit.SECONDS);
+
+    assertThat(days).hasSize(31);
+  }
+
+  private static class StopableThread implements Runnable {
+    private AtomicBoolean running = new AtomicBoolean(true);
+
+    @Override
+    public void run() {
+      while (running.get()) {}
+    }
+
+    public void stop() {
+      running.set(false);
+    }
+  }
+}