Delegates example

jeorg-kotlin-crums/jeorg-kotlin-crums-4-variance/src/main/kotlin/org/jesperancinha/ktd/Delegates.kt

@@ -0,0 +1,53 @@
+package org.jesperancinha.ktd
+
+import java.time.LocalDateTime
+
+interface Person {
+    val name: String
+    val address: String
+}
+
+interface Card {
+    val cardNumber: Long
+    val expiryDate: LocalDateTime
+}
+
+data class Client(
+    override val name: String,
+    override val address: String
+) : Person
+
+data class DebitCard(
+    override val cardNumber: Long,
+    override val expiryDate: LocalDateTime
+) : Card
+
+class Account(
+    person: Person,
+    card: Card,
+    val number: String
+) : Person by person, Card by card
+
+class Delegates {
+    companion object {
+        @JvmStatic
+        fun main(args: Array<String> = emptyArray()) {
+            val account = Account(
+                Client(
+                    name = "João",
+                    address = "World"
+                ),
+                DebitCard(
+                    cardNumber = 1111111111111111,
+                    expiryDate = LocalDateTime.now()
+                ),
+                number = "AAABBB12312313-3243242-23432"
+            )
+            println(account.number)
+            println(account.name)
+            println(account.address)
+            println(account.cardNumber)
+            println(account.expiryDate)
+        }
+    }
+}

jeorg-kotlin-crums/jeorg-kotlin-crums-4-variance/src/main/kotlin/org/jesperancinha/ktd/Main.kt

@@ -1,6 +1,7 @@
 package org.jesperancinha.ktd
 
 import org.jesperancinha.ktd.crum5.Patisserie
+import org.jesperancinha.ktd.delegates.Account
 
 class Main {
     companion object {
@@ -14,6 +15,8 @@ class Main {
             WarehouseManager.main()
             TailRec.main()
             FloatVsDouble.main()
+            Delegates.main()
+            Account.main(emptyArray())
         }
     }
 }

jeorg-kotlin-crums/jeorg-kotlin-crums-4-variance/src/main/kotlin/org/jesperancinha/ktd/delegates/Account.java

@@ -0,0 +1,49 @@
+package org.jesperancinha.ktd.delegates;
+
+import java.time.LocalDateTime;
+
+public record Account(
+        Person person,
+        Card card,
+        String number
+
+) implements Card, Person {
+    @Override
+    public LocalDateTime expiryDate() {
+        return card.expiryDate();
+    }
+
+    @Override
+    public Long cardNumber() {
+        return card.cardNumber();
+    }
+
+    @Override
+    public String name() {
+        return person.name();
+    }
+
+    @Override
+    public String address() {
+        return person.address();
+    }
+
+    public static void main(String[] args) {
+        var account = new Account(
+                new Client(
+                        "João",
+                        "World"
+                ),
+                new DebitCard(
+                        1111111111111111L,
+                        LocalDateTime.now()
+                ),
+                "AAABBB12312313-3243242-23432"
+        );
+        System.out.println(account.number);
+        System.out.println(account.name());
+        System.out.println(account.address());
+        System.out.println(account.cardNumber());
+        System.out.println(account.expiryDate());
+    }
+}

jeorg-kotlin-crums/jeorg-kotlin-crums-4-variance/src/main/kotlin/org/jesperancinha/ktd/delegates/Card.java

@@ -0,0 +1,9 @@
+package org.jesperancinha.ktd.delegates;
+
+import java.time.LocalDateTime;
+
+public interface Card {
+    LocalDateTime expiryDate();
+
+    Long cardNumber();
+}

jeorg-kotlin-crums/jeorg-kotlin-crums-4-variance/src/main/kotlin/org/jesperancinha/ktd/delegates/Client.java

@@ -0,0 +1,14 @@
+package org.jesperancinha.ktd.delegates;
+
+
+public record  Client(String name, String address) implements Person{
+    @Override
+    public String name() {
+        return name;
+    }
+
+    @Override
+    public String address() {
+        return address;
+    }
+}

jeorg-kotlin-crums/jeorg-kotlin-crums-4-variance/src/main/kotlin/org/jesperancinha/ktd/delegates/DebitCard.java

@@ -0,0 +1,5 @@
+package org.jesperancinha.ktd.delegates;
+
+import java.time.LocalDateTime;
+
+public record DebitCard(Long cardNumber, LocalDateTime expiryDate) implements Card{}

jeorg-kotlin-crums/jeorg-kotlin-crums-4-variance/src/main/kotlin/org/jesperancinha/ktd/delegates/Person.java

@@ -0,0 +1,7 @@
+package org.jesperancinha.ktd.delegates;
+
+public interface Person {
+    String name();
+
+    String address();
+}