.idea/inspectionProfiles/Project_Default.xml

@@ -0,0 +1,6 @@
+<component name="InspectionProjectProfileManager">
+  <profile version="1.0">
+    <option name="myName" value="Project Default" />
+    <inspection_tool class="TsLint" enabled="true" level="WARNING" enabled_by_default="true" />
+  </profile>
+</component>

core-java-modules/core-java-lambdas/src/main/java/com/ossez/anonymousclass/EmailSenderService.java

@@ -0,0 +1,10 @@
+package com.ossez.anonymousclass;
+
+public class EmailSenderService implements SenderService {
+
+    @Override
+    public String callSender(Sender sender) {
+        return sender.send("Email Notification");
+    }
+
+}

core-java-modules/core-java-lambdas/src/main/java/com/ossez/anonymousclass/Sender.java

@@ -0,0 +1,7 @@
+package com.ossez.anonymousclass;
+
+public interface Sender {
+
+    String send(final String message);
+
+}

core-java-modules/core-java-lambdas/src/main/java/com/ossez/anonymousclass/SenderService.java

@@ -0,0 +1,7 @@
+package com.ossez.anonymousclass;
+
+public interface SenderService {
+
+    String callSender(Sender sender);
+
+}

core-java-modules/core-java-lambdas/src/main/java/com/ossez/anonymousclass/SmsSenderService.java

@@ -0,0 +1,10 @@
+package com.ossez.anonymousclass;
+
+public class SmsSenderService implements SenderService {
+
+    @Override
+    public String callSender(Sender sender) {
+        return sender.send("SMS Notification");
+    }
+
+}

core-java-modules/core-java-lambdas/src/main/java/com/ossez/java8/lambda/serialization/SerializableLambdaExpression.java

@@ -0,0 +1,10 @@
+package com.ossez.java8.lambda.serialization;
+
+import java.io.Serializable;
+
+public class SerializableLambdaExpression {
+    public static Object getLambdaExpressionObject() {
+        Runnable r = (Runnable & Serializable) () -> System.out.println("please serialize this message");
+        return r;
+    }
+}

core-java-modules/core-java-lambdas/src/main/java/com/ossez/suppliercallable/data/User.java

@@ -0,0 +1,59 @@
+package com.ossez.suppliercallable.data;
+
+import java.time.LocalDate;
+
+public class User {
+
+    private String name;
+    private String surname;
+    private LocalDate birthDate;
+    private Integer age;
+    private Boolean canDriveACar = false;
+
+    public User(String name, String surname, LocalDate birthDate) {
+        this.name = name;
+        this.surname = surname;
+        this.birthDate = birthDate;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getSurname() {
+        return surname;
+    }
+
+    public void setSurname(String surname) {
+        this.surname = surname;
+    }
+
+    public LocalDate getBirthDate() {
+        return birthDate;
+    }
+
+    public void setBirthDate(LocalDate birthDate) {
+        this.birthDate = birthDate;
+    }
+
+    public void setAge(Integer age) {
+        this.age = age;
+    }
+
+    public Integer getAge() {
+        return age;
+    }
+
+    public Boolean getCanDriveACar() {
+        return canDriveACar;
+    }
+
+    public void setCanDriveACar(Boolean canDriveACar) {
+        this.canDriveACar = canDriveACar;
+    }
+
+}

core-java-modules/core-java-lambdas/src/main/java/com/ossez/suppliercallable/service/Service.java

@@ -0,0 +1,8 @@
+package com.ossez.suppliercallable.service;
+
+import com.ossez.suppliercallable.data.User;
+
+public interface Service {
+
+    User execute(User user);
+}

core-java-modules/core-java-lambdas/src/main/java/com/ossez/suppliercallable/service/callable/AgeCalculatorCallable.java

@@ -0,0 +1,20 @@
+package com.ossez.suppliercallable.service.callable;
+
+import java.time.LocalDate;
+import java.time.Period;
+import java.util.concurrent.Callable;
+
+public class AgeCalculatorCallable implements Callable<Integer> {
+
+    private final LocalDate birthDate;
+
+    @Override
+    public Integer call() throws Exception {
+        return Period.between(birthDate, LocalDate.now())
+          .getYears();
+    }
+
+    public AgeCalculatorCallable(LocalDate birthDate) {
+        this.birthDate = birthDate;
+    }
+}

core-java-modules/core-java-lambdas/src/main/java/com/ossez/suppliercallable/service/callable/CallableServiceImpl.java

@@ -0,0 +1,31 @@
+package com.ossez.suppliercallable.service.callable;
+
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+
+import com.ossez.suppliercallable.data.User;
+import com.ossez.suppliercallable.service.Service;
+
+public class CallableServiceImpl implements Service {
+
+    @Override
+    public User execute(User user) {
+        ExecutorService executorService = Executors.newCachedThreadPool();
+
+        try {
+            Future<Integer> ageFuture = executorService.submit(new AgeCalculatorCallable(user.getBirthDate()));
+            Integer age = ageFuture.get();
+            Future<Boolean> canDriveACarFuture = executorService.submit(new CarDriverValidatorCallable(age));
+            Boolean canDriveACar = canDriveACarFuture.get();
+            user.setAge(age);
+            user.setCanDriveACar(canDriveACar);
+        } catch (ExecutionException | InterruptedException e) {
+            throw new RuntimeException(e.getCause());
+        }
+
+        return user;
+    }
+
+}

core-java-modules/core-java-lambdas/src/main/java/com/ossez/suppliercallable/service/callable/CarDriverValidatorCallable.java

@@ -0,0 +1,17 @@
+package com.ossez.suppliercallable.service.callable;
+
+import java.util.concurrent.Callable;
+
+public class CarDriverValidatorCallable implements Callable<Boolean> {
+
+    private final Integer age;
+
+    @Override
+    public Boolean call() throws Exception {
+        return age > 18;
+    }
+
+    public CarDriverValidatorCallable(Integer age) {
+        this.age = age;
+    }
+}

core-java-modules/core-java-lambdas/src/main/java/com/ossez/suppliercallable/service/supplier/SupplierServiceImpl.java

@@ -0,0 +1,26 @@
+package com.ossez.suppliercallable.service.supplier;
+
+import java.time.LocalDate;
+import java.time.Period;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+import com.ossez.suppliercallable.data.User;
+import com.ossez.suppliercallable.service.Service;
+
+public class SupplierServiceImpl implements Service {
+    @Override
+    public User execute(User user) {
+        ExecutorService executorService = Executors.newCachedThreadPool();
+        CompletableFuture<Integer> ageFut = CompletableFuture.supplyAsync(() -> Period.between(user.getBirthDate(), LocalDate.now())
+          .getYears(), executorService)
+          .exceptionally((throwable -> null));
+        CompletableFuture<Boolean> canDriveACarFut = ageFut.thenComposeAsync(age -> CompletableFuture.supplyAsync(() -> age > 18, executorService))
+          .exceptionally((ex) -> false);
+        user.setAge(ageFut.join());
+        user.setCanDriveACar(canDriveACarFut.join());
+        return user;
+    }
+
+}

core-java-modules/core-java-lambdas/src/test/java/com/ossez/anonymousclass/AnonymousClassToLambdaIntegrationTest.java

@@ -0,0 +1,38 @@
+package com.ossez.anonymousclass;
+
+import static org.junit.Assert.assertEquals;
+
+import com.ossez.anonymousclass.EmailSenderService;
+import com.ossez.anonymousclass.Sender;
+import com.ossez.anonymousclass.SenderService;
+import com.ossez.anonymousclass.SmsSenderService;
+import org.junit.Test;
+
+public class AnonymousClassToLambdaIntegrationTest {
+
+    @Test
+    public void whenPassingAnonymousClass_thenSuccess() {
+        final SenderService emailSenderService = new EmailSenderService();
+
+        final String emailNotif = emailSenderService.callSender(new Sender() {
+            @Override
+            public String send(String message) {
+                return message;
+            }
+        });
+
+        assertEquals(emailNotif, "Email Notification");
+    }
+
+    @Test
+    public void whenPassingLambdaExpression_thenSuccess() {
+        final SenderService smsSenderService = new SmsSenderService();
+
+        final String smsNotif = smsSenderService.callSender((String message) -> {
+            return message;
+        });
+
+        assertEquals(smsNotif, "SMS Notification");
+    }
+
+}

core-java-modules/core-java-lambdas/src/test/java/com/ossez/java8/lambda/serialization/LambdaSerializationUnitTest.java

@@ -0,0 +1,79 @@
+package com.ossez.java8.lambda.serialization;
+
+import com.ossez.java8.lambda.serialization.NotSerializableLambdaExpression;
+import com.ossez.java8.lambda.serialization.SerializableLambdaExpression;
+import org.junit.Test;
+
+import java.io.*;
+import java.nio.file.Files;
+import java.util.function.Consumer;
+import java.util.function.Function;
+
+import static org.junit.Assert.assertTrue;
+
+public class LambdaSerializationUnitTest {
+    @Test(expected = NotSerializableException.class)
+    public void givenRunnable_whenNoCapturing_thenSerializationFailed() throws IOException, ClassNotFoundException {
+        Object obj = NotSerializableLambdaExpression.getLambdaExpressionObject();
+        writeAndReadObject(obj, Runnable.class);
+    }
+
+    @Test
+    public void givenIntersectionType_whenNoCapturing_thenSerializationSuccess() throws IOException, ClassNotFoundException {
+        Object obj = SerializableLambdaExpression.getLambdaExpressionObject();
+        writeAndReadObject(obj, Runnable.class);
+    }
+
+    @Test
+    public void givenSerializableRunnable_whenNoCapturing_thenSerializationSuccess() throws IOException, ClassNotFoundException {
+        SerializableRunnable obj = () -> System.out.println("please serialize this message");
+        writeAndReadObject(obj, SerializableRunnable.class);
+    }
+
+    @Test
+    public void givenSerializableFunction_whenNoCapturing_thenSerializationSuccess() throws IOException, ClassNotFoundException {
+        SerializableFunction<String, String> obj = message -> String.format("Hello %s", message);
+        writeAndReadObject(obj, SerializableFunction.class);
+    }
+
+    @Test
+    public void givenSerializableConsumer_whenNoCapturing_thenSerializationSuccess() throws IOException, ClassNotFoundException {
+        SerializableConsumer<String> obj = message -> System.out.println(message);
+        writeAndReadObject(obj, SerializableConsumer.class);
+    }
+
+    @Test(expected = NotSerializableException.class)
+    public void givenSerializableConsumer_whenCapturingNotSerializable_thenSerializationFailed() throws IOException, ClassNotFoundException {
+        SerializableConsumer<String> obj = System.out::println;
+        writeAndReadObject(obj, SerializableConsumer.class);
+    }
+
+    private <T> void writeAndReadObject(Object obj, Class<T> clazz) throws IOException, ClassNotFoundException {
+        File file = Files.createTempFile("lambda", "ser").toFile();
+        try (
+                FileOutputStream fos = new FileOutputStream(file);
+                ObjectOutputStream oos = new ObjectOutputStream(fos)
+        ) {
+            oos.writeObject(obj);
+        }
+
+        try (
+                FileInputStream fis = new FileInputStream(file);
+                ObjectInputStream ois = new ObjectInputStream(fis)
+        ) {
+            Object newObj = ois.readObject();
+            boolean isInstance = clazz.isInstance(newObj);
+
+            assertTrue(isInstance);
+        }
+    }
+
+    interface SerializableRunnable extends Runnable, Serializable {
+    }
+
+    interface SerializableFunction<T, R> extends Function<T, R>, Serializable {
+    }
+
+    interface SerializableConsumer<T> extends Consumer<T>, Serializable {
+    }
+}

core-java-modules/core-java-lambdas/src/test/java/com/ossez/suppliercallable/CallableSupplierUnitTest.java

@@ -0,0 +1,64 @@
+package com.ossez.suppliercallable;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import java.time.LocalDate;
+import java.time.Month;
+import org.junit.jupiter.api.Test;
+import com.ossez.suppliercallable.data.User;
+import com.ossez.suppliercallable.service.Service;
+import com.ossez.suppliercallable.service.callable.CallableServiceImpl;
+import com.ossez.suppliercallable.service.supplier.SupplierServiceImpl;
+
+public class CallableSupplierUnitTest {
+
+    @Test
+    void givenCallableService_whenUserIsAnAdult_thenCanDriveACar() {
+        User user = new User("Test", "Test", LocalDate.of(2000, Month.JANUARY, 19));
+        Service service = new CallableServiceImpl();
+        service.execute(user);
+        assertEquals(true, user.getCanDriveACar());
+    }
+
+    @Test
+    void givenCallableService_whenUserIsNotAnAdult_thenCannotDriveACar() {
+        User user = new User("Test", "Test", LocalDate.of(2010, Month.JANUARY, 19));
+        Service service = new CallableServiceImpl();
+        service.execute(user);
+        assertEquals(false, user.getCanDriveACar());
+    }
+
+    @Test
+    void givenCallableService_whenBirthDateIsNull_thenShouldThrowAnException() {
+        User user = new User("Test", "Test", null);
+        Service service = new CallableServiceImpl();
+        assertThrows(RuntimeException.class, () -> service.execute(user));
+    }
+
+    @Test
+    void givenSupplierService_whenUserIsAnAdult_thenCanDriveACar() {
+        User user = new User("Test", "Test", LocalDate.of(2000, Month.JANUARY, 19));
+        Service service = new SupplierServiceImpl();
+        service.execute(user);
+        assertEquals(true, user.getCanDriveACar());
+    }
+
+    @Test
+    void givenSupplierService_whenUserIsNotAnAdult_thenCannotDriveACar() {
+        User user = new User("Test", "Test", LocalDate.of(2010, Month.JANUARY, 19));
+        Service service = new SupplierServiceImpl();
+        service.execute(user);
+        assertEquals(false, user.getCanDriveACar());
+    }
+
+    @Test
+    void givenSupplierService_whenBirthDateIsNull_thenCannotDriveACarAndAgeIsNull() {
+        User user = new User("Test", "Test", null);
+        Service service = new SupplierServiceImpl();
+        service.execute(user);
+        assertEquals(false, user.getCanDriveACar());
+        assertNull(user.getBirthDate());
+    }
+
+}