Add abstract factory implementation with test scenario (#48)

Author: mperor

DesignPatterns/src/main/java/pl/mperor/lab/java/design/pattern/creational/factory/abs/AppStarter.java

@@ -0,0 +1,20 @@
+package pl.mperor.lab.java.design.pattern.creational.factory.abs;
+
+public class AppStarter {
+
+    public static void startup(Profile profile) {
+        StarterFactory starter = switch (profile) {
+            case PROD -> new ProdStarterFactory();
+            case DEV -> new DevStarterFactory();
+        };
+
+        starter.getDatabaseConnection().connect();
+        starter.getLoggingService().init();
+        starter.getSecurityPolicy().applyPolicy();
+    }
+
+    public enum Profile {
+        PROD,
+        DEV;
+    }
+}

DesignPatterns/src/main/java/pl/mperor/lab/java/design/pattern/creational/factory/abs/DatabaseConnection.java

@@ -0,0 +1,5 @@
+package pl.mperor.lab.java.design.pattern.creational.factory.abs;
+
+public interface DatabaseConnection {
+    void connect();
+}

DesignPatterns/src/main/java/pl/mperor/lab/java/design/pattern/creational/factory/abs/DevStarterFactory.java

@@ -0,0 +1,19 @@
+package pl.mperor.lab.java.design.pattern.creational.factory.abs;
+
+public class DevStarterFactory implements StarterFactory {
+
+    @Override
+    public DatabaseConnection getDatabaseConnection() {
+        return () -> System.out.println("Connecting to in-memory H2 database 🗄️.");
+    }
+
+    @Override
+    public LoggingService getLoggingService() {
+        return () -> System.out.println("Using DEV 🟩 logging service.");
+    }
+
+    @Override
+    public SecurityPolicy getSecurityPolicy() {
+        return () -> System.out.println("🔓 Applying no security.");
+    }
+}

DesignPatterns/src/main/java/pl/mperor/lab/java/design/pattern/creational/factory/abs/LoggingService.java

@@ -0,0 +1,5 @@
+package pl.mperor.lab.java.design.pattern.creational.factory.abs;
+
+public interface LoggingService {
+    void init();
+}

DesignPatterns/src/main/java/pl/mperor/lab/java/design/pattern/creational/factory/abs/ProdStarterFactory.java

@@ -0,0 +1,19 @@
+package pl.mperor.lab.java.design.pattern.creational.factory.abs;
+
+public class ProdStarterFactory implements StarterFactory {
+
+    @Override
+    public DatabaseConnection getDatabaseConnection() {
+        return () -> System.out.println("Connecting to PostgreSQL database 🗄️.");
+    }
+
+    @Override
+    public LoggingService getLoggingService() {
+        return () -> System.out.println("Using PROD 🟥 logging service.");
+    }
+
+    @Override
+    public SecurityPolicy getSecurityPolicy() {
+        return () -> System.out.println("🔒 Applying strict security policies.");
+    }
+}

DesignPatterns/src/main/java/pl/mperor/lab/java/design/pattern/creational/factory/abs/SecurityPolicy.java

@@ -0,0 +1,5 @@
+package pl.mperor.lab.java.design.pattern.creational.factory.abs;
+
+public interface SecurityPolicy {
+    void applyPolicy();
+}

DesignPatterns/src/main/java/pl/mperor/lab/java/design/pattern/creational/factory/abs/StarterFactory.java

@@ -0,0 +1,10 @@
+package pl.mperor.lab.java.design.pattern.creational.factory.abs;
+
+public interface StarterFactory {
+
+    DatabaseConnection getDatabaseConnection();
+
+    LoggingService getLoggingService();
+
+    SecurityPolicy getSecurityPolicy();
+}

DesignPatterns/src/main/java/pl/mperor/lab/java/design/pattern/creational/factory/basic/AnimalFactoryEnumImpl.java

@@ -12,9 +12,9 @@ public Animal getNewInstance(AnimalType type) {
     }
 
     public enum AnimalType {
-        DOG(() -> new Dog()),
-        CAT(() -> new Cat()),
-        FLY(() -> new Fly());
+        DOG(Dog::new),
+        CAT(Cat::new),
+        FLY(Fly::new);
 
         private final Supplier<Animal> creator;
 

DesignPatterns/src/main/java/pl/mperor/lab/java/design/pattern/creational/factory/basic/AnimalFactoryMapImpl.java

@@ -9,9 +9,9 @@ public class AnimalFactoryMapImpl implements AnimalFactory<String> {
     private final Map<String, Supplier<Animal>> nameToCreator = new HashMap<>();
 
     public AnimalFactoryMapImpl() {
-        nameToCreator.put(Fly.NAME, () -> new Fly());
-        nameToCreator.put(Dog.NAME, () -> new Dog());
-        nameToCreator.put(Cat.NAME, () -> new Cat());
+        nameToCreator.put(Fly.NAME, Fly::new);
+        nameToCreator.put(Dog.NAME, Dog::new);
+        nameToCreator.put(Cat.NAME, Cat::new);
     }
 
     public Animal getNewInstance(String type) {

DesignPatterns/src/test/java/pl/mperor/lab/java/design/pattern/creational/factory/abs/AppStarterAbstractFactoryTest.java

@@ -0,0 +1,36 @@
+package pl.mperor.lab.java.design.pattern.creational.factory.abs;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+import pl.mperor.lab.common.TestUtils;
+
+import java.util.stream.Stream;
+
+public class AppStarterAbstractFactoryTest {
+
+    @Test
+    public void shouldAllowToCreateAppStarterForConcreteProfile() {
+        var out = TestUtils.setTempSystemOut();
+
+        AppStarter.startup(AppStarter.Profile.DEV);
+        Assertions.assertLinesMatch(
+                Stream.of(
+                        "Connecting to in-memory H2 database 🗄️.",
+                        "Using DEV 🟩 logging service.",
+                        "🔓 Applying no security."
+                ), out.all().lines()
+        );
+
+        AppStarter.startup(AppStarter.Profile.PROD);
+        Assertions.assertLinesMatch(
+                Stream.of(
+                        "Connecting to PostgreSQL database 🗄️.",
+                        "Using PROD 🟥 logging service.",
+                        "🔒 Applying strict security policies."
+                ), out.all().lines().skip(3)
+        );
+
+        TestUtils.resetSystemOut();
+    }
+
+}