Added exercise space-age (see #3)

config.json

@@ -13,10 +13,10 @@
     "robot-name",
     "meetup",
     "phone-number",
-    "grade-school"
+    "grade-school",
+    "space-age"
   ],
   "deprecated": [
-
   ],
   "ignored": [
     "_template",

space-age/build.gradle

@@ -0,0 +1,11 @@
+apply plugin: "java"
+apply plugin: "eclipse"
+apply plugin: "idea"
+
+repositories {
+  mavenCentral()
+}
+
+dependencies {
+  testCompile "junit:junit:4.10"
+}

space-age/example.java

@@ -0,0 +1,69 @@
+public class SpaceAge {
+
+    private enum Planet {
+        EARTH, MERCURY, VENUS, MARS, JUPITER, SATURN, URANUS, NEPTUNE
+    }
+
+    private double seconds;
+
+    private static final double EARTH_ORBITAL_PERIOD_IN_SECONDS = 31557600.0;
+    private static final int PRECISION = 2;
+    private static final Map<Planet, Double> relativeOrbitalPeriods = new HashMap<>();
+
+    static {
+        relativeOrbitalPeriods.put(Planet.EARTH, 1.0);
+        relativeOrbitalPeriods.put(Planet.MERCURY, 0.2408467);
+        relativeOrbitalPeriods.put(Planet.VENUS, 0.61519726);
+        relativeOrbitalPeriods.put(Planet.MARS, 1.8808158);
+        relativeOrbitalPeriods.put(Planet.JUPITER, 11.862615);
+        relativeOrbitalPeriods.put(Planet.SATURN, 29.447498);
+        relativeOrbitalPeriods.put(Planet.URANUS, 84.016846);
+        relativeOrbitalPeriods.put(Planet.NEPTUNE, 164.79132);
+    }
+
+    public SpaceAge(double seconds) {
+        this.seconds = seconds;
+    }
+
+    public double getSeconds() {
+        return seconds;
+    }
+
+    public double onEarth() {
+        return calculateAge(relativeOrbitalPeriods.get(Planet.EARTH));
+    }
+
+    public double onMercury() {
+        return calculateAge(relativeOrbitalPeriods.get(Planet.MERCURY));
+    }
+
+    public double onVenus() {
+        return calculateAge(relativeOrbitalPeriods.get(Planet.VENUS));
+    }
+
+    public double onMars() {
+        return calculateAge(relativeOrbitalPeriods.get(Planet.MARS));
+    }
+
+    public double onJupiter() {
+        return calculateAge(relativeOrbitalPeriods.get(Planet.JUPITER));
+    }
+
+    public double onSaturn() {
+        return calculateAge(relativeOrbitalPeriods.get(Planet.SATURN));
+    }
+
+    public double onUranus() {
+        return calculateAge(relativeOrbitalPeriods.get(Planet.URANUS));
+    }
+
+    public double onNeptune() {
+        return calculateAge(relativeOrbitalPeriods.get(Planet.NEPTUNE));
+    }
+
+    private double calculateAge(double relativeOrbitalPeriod) {
+        double age = seconds / (EARTH_ORBITAL_PERIOD_IN_SECONDS * relativeOrbitalPeriod);
+
+        return new BigDecimal(age).setScale(PRECISION, BigDecimal.ROUND_HALF_UP).doubleValue();
+    }
+}

space-age/src/main/java/SpaceAge.java

@@ -0,0 +1,2 @@
+public class SpaceAge {
+}

space-age/src/test/java/SpaceAgeTest.java

@@ -0,0 +1,76 @@
+import org.junit.Test;
+
+public class SpaceAgeTest {
+
+    private static final double MAXIMUM_DELTA = 1E-02;
+
+    @Test
+    public void ageInSeconds() {
+        SpaceAge age = new SpaceAge(1000000);
+
+        assertEquals(age.getSeconds(), 1000000, MAXIMUM_DELTA);
+    }
+
+    @Test
+    public void ageOnEarth() {
+        SpaceAge age = new SpaceAge(1000000000);
+
+        assertEquals(age.onEarth(), 31.69, MAXIMUM_DELTA);
+    }
+
+    @Test
+    public void ageOnMercury() {
+        SpaceAge age = new SpaceAge(2134835688);
+
+        assertEquals(age.onEarth(), 67.65, MAXIMUM_DELTA);
+        assertEquals(age.onMercury(), 280.88, MAXIMUM_DELTA);
+    }
+
+    @Test
+    public void ageOnVenus() {
+        SpaceAge age = new SpaceAge(189839836);
+
+        assertEquals(age.onEarth(), 6.02, MAXIMUM_DELTA);
+        assertEquals(age.onVenus(), 9.78, MAXIMUM_DELTA);
+    }
+
+    @Test
+    public void ageOnMars() {
+        SpaceAge age = new SpaceAge(2329871239L);
+
+        assertEquals(age.onEarth(), 73.83, MAXIMUM_DELTA);
+        assertEquals(age.onMars(), 39.25, MAXIMUM_DELTA);
+    }
+
+    @Test
+    public void ageOnJupiter() {
+        SpaceAge age = new SpaceAge(901876382);
+
+        assertEquals(age.onEarth(), 28.58, MAXIMUM_DELTA);
+        assertEquals(age.onJupiter(), 2.41, MAXIMUM_DELTA);
+    }
+
+    @Test
+    public void ageOnSaturn() {
+        SpaceAge age = new SpaceAge(3000000000L);
+
+        assertEquals(age.onEarth(), 95.06, MAXIMUM_DELTA);
+        assertEquals(age.onSaturn(), 3.23, MAXIMUM_DELTA);
+    }
+
+    @Test
+    public void ageOnUranus() {
+        SpaceAge age = new SpaceAge(3210123456L);
+
+        assertEquals(age.onEarth(), 101.72, MAXIMUM_DELTA);
+        assertEquals(age.onUranus(), 1.21, MAXIMUM_DELTA);
+    }
+
+    @Test
+    public void ageOnNeptune() {
+        SpaceAge age = new SpaceAge(8210123456L);
+
+        assertEquals(age.onEarth(), 260.16, MAXIMUM_DELTA);
+        assertEquals(age.onNeptune(), 1.58, MAXIMUM_DELTA);
+    }
+}