From e968f0352f6d2c29665311ca215550fa16d90fe5 Mon Sep 17 00:00:00 2001
From: Fabio Scotto di Santolo <fabio.scottodisantolo@nttdata.com>
Date: Thu, 28 Nov 2019 18:13:31 +0100
Subject: [PATCH] Esempi con gli Optional

---
 .../org/gym/fp/moderjava/OptionalTest.java    | 33 +++++++++++++++++++
 .../org/gym/fp/moderjava/optional/Car.java    | 17 ++++++++++
 .../gym/fp/moderjava/optional/Insurance.java  | 16 +++++++++
 .../org/gym/fp/moderjava/optional/Person.java | 18 ++++++++++
 4 files changed, 84 insertions(+)
 create mode 100644 modern-java/src/main/java/org/gym/fp/moderjava/OptionalTest.java
 create mode 100644 modern-java/src/main/java/org/gym/fp/moderjava/optional/Car.java
 create mode 100644 modern-java/src/main/java/org/gym/fp/moderjava/optional/Insurance.java
 create mode 100644 modern-java/src/main/java/org/gym/fp/moderjava/optional/Person.java

diff --git a/modern-java/src/main/java/org/gym/fp/moderjava/OptionalTest.java b/modern-java/src/main/java/org/gym/fp/moderjava/OptionalTest.java
new file mode 100644
index 0000000..18793be
--- /dev/null
+++ b/modern-java/src/main/java/org/gym/fp/moderjava/OptionalTest.java
@@ -0,0 +1,33 @@
+package org.gym.fp.moderjava;
+
+import org.gym.fp.moderjava.optional.Car;
+import org.gym.fp.moderjava.optional.Insurance;
+import org.gym.fp.moderjava.optional.Person;
+
+import java.util.Optional;
+
+import static java.lang.System.out;
+
+public class OptionalTest {
+
+    public static void main(String[] args) {
+        Insurance myInsurance1 = new Insurance("Allianz");
+        Car myCar1 = new Car(Optional.of(myInsurance1));
+        Person person1 = new Person(Optional.of(myCar1));
+        out.println("My insurance's name is " + getCarInsuranceName(Optional.ofNullable(person1)));
+        out.println("----------------------------------------");
+        Car myCar2 = new Car(Optional.ofNullable(null));
+        Person person2 = new Person(Optional.ofNullable(myCar2));
+        out.println("My insurance's name is " + getCarInsuranceName(Optional.ofNullable(person2)));
+        out.println("----------------------------------------");
+    }
+
+    static String getCarInsuranceName(Optional<Person> maybePerson) {
+        return maybePerson
+                .flatMap(Person::getCar)
+                .flatMap(Car::getInsurance)
+                .map(Insurance::getName)
+                .orElse("Unknown");
+    }
+
+}
diff --git a/modern-java/src/main/java/org/gym/fp/moderjava/optional/Car.java b/modern-java/src/main/java/org/gym/fp/moderjava/optional/Car.java
new file mode 100644
index 0000000..9bf9f79
--- /dev/null
+++ b/modern-java/src/main/java/org/gym/fp/moderjava/optional/Car.java
@@ -0,0 +1,17 @@
+package org.gym.fp.moderjava.optional;
+
+import lombok.Getter;
+import lombok.ToString;
+
+import java.util.Optional;
+
+@ToString
+public class Car {
+
+    @Getter
+    private Optional<Insurance> insurance;
+
+    public Car(Optional<Insurance> insurance) {
+        this.insurance = insurance;
+    }
+}
diff --git a/modern-java/src/main/java/org/gym/fp/moderjava/optional/Insurance.java b/modern-java/src/main/java/org/gym/fp/moderjava/optional/Insurance.java
new file mode 100644
index 0000000..4ea8ded
--- /dev/null
+++ b/modern-java/src/main/java/org/gym/fp/moderjava/optional/Insurance.java
@@ -0,0 +1,16 @@
+package org.gym.fp.moderjava.optional;
+
+import lombok.Getter;
+import lombok.ToString;
+
+@ToString
+public class Insurance {
+
+    @Getter
+    private String name;
+
+    public Insurance(String name) {
+        this.name = name;
+    }
+
+}
diff --git a/modern-java/src/main/java/org/gym/fp/moderjava/optional/Person.java b/modern-java/src/main/java/org/gym/fp/moderjava/optional/Person.java
new file mode 100644
index 0000000..4ec0b32
--- /dev/null
+++ b/modern-java/src/main/java/org/gym/fp/moderjava/optional/Person.java
@@ -0,0 +1,18 @@
+package org.gym.fp.moderjava.optional;
+
+import lombok.Getter;
+import lombok.ToString;
+
+import java.util.Optional;
+
+@ToString
+public class Person {
+
+    @Getter
+    private Optional<Car> car;
+
+    public Person(Optional<Car> car) {
+        this.car = car;
+    }
+
+}