initial commit

core-banking/src/com/example/banking/application/StudyPolymorphism.java

@@ -0,0 +1,29 @@
+package com.example.banking.application;
+
+import java.util.List;
+import java.util.concurrent.ThreadLocalRandom;
+
+import com.example.banking.domain.Account;
+import com.example.banking.domain.CheckingAccount;
+
+public class StudyPolymorphism {
+
+	public static void main(String[] args) {
+		Account account ;
+
+		if (ThreadLocalRandom.current().nextBoolean()) {
+			account = new Account("tr1", 10_000);
+		} else {
+			account = new CheckingAccount("tr1", 10_000, 2_000);			
+		}
+		System.err.println(account.getClass());
+		account.withdraw(3_000);
+
+		List<Account> accounts = List.of(
+				new Account("tr1", 10_000),
+				new CheckingAccount("tr1", 10_000, 2_000)
+		);
+
+	}
+
+}

core-banking/src/com/example/banking/domain/Account.java

@@ -11,7 +11,7 @@ public class Account extends Object { // DDD -> Entity
 	// i) instance variable (Heap) ii) reference variable
 	private final String iban; 
 	// i) instance variable (Heap) ii) value-typed variable
-	private double balance; 
+	protected double balance; 
 	// public methods
 	// 2 Overloaded (1) Constructors
 	public Account(String iban, double balance) {
@@ -40,6 +40,7 @@ public boolean deposit(double amount) {
 	}
 
 	public boolean withdraw(double amount) {
+		System.err.println("Account::withdraw");
 		// validation
 		if (amount <= 0.0) return false;
 		// business rule

core-banking/src/com/example/banking/domain/CheckingAccount.java

@@ -1,12 +1,34 @@
 package com.example.banking.domain;
 // Account         -> super-class / base class
 // CheckingAccount -> sub-class   / derived class
-public class CheckingAccount extends Account {
-     private double overdraftAmount;
+public class CheckingAccount extends Account { // Single Inheritance
+     private final double overdraftAmount;
 
 	public CheckingAccount(String iban, double balance, double overdraftAmount) {
 		super(iban, balance);
 		this.overdraftAmount = overdraftAmount;
 	}
-
+
+	public double getOverdraftAmount() {
+		return overdraftAmount;
+	}
+
+	@Override
+	public boolean withdraw(double amount) {
+		System.err.println("CheckingAccount::withdraw");
+		if (amount <= 0.0) return false;
+		if (amount > (balance + overdraftAmount)) return false;
+		this.balance -= amount;
+		return true;
+	}
+
+	@Override
+	public String toString() {
+		return "CheckingAccount [overdraftAmount=" + overdraftAmount + ", balance=" + balance + ", iban="
+				+ getIban() + "]";
+	}
+
+
+
+
 }

zoo/.classpath

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<classpath>
+	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-17">
+		<attributes>
+			<attribute name="module" value="true"/>
+		</attributes>
+	</classpathentry>
+	<classpathentry kind="src" path="src"/>
+	<classpathentry kind="output" path="bin"/>
+</classpath>

zoo/.project

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+	<name>zoo</name>
+	<comment></comment>
+	<projects>
+	</projects>
+	<buildSpec>
+		<buildCommand>
+			<name>org.eclipse.jdt.core.javabuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+	</buildSpec>
+	<natures>
+		<nature>org.eclipse.jdt.core.javanature</nature>
+	</natures>
+</projectDescription>

zoo/.settings/org.eclipse.core.resources.prefs

@@ -0,0 +1,2 @@
+eclipse.preferences.version=1
+encoding/<project>=UTF-8

zoo/.settings/org.eclipse.jdt.core.prefs

@@ -0,0 +1,14 @@
+eclipse.preferences.version=1
+org.eclipse.jdt.core.compiler.codegen.inlineJsrBytecode=enabled
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=17
+org.eclipse.jdt.core.compiler.codegen.unusedLocal=preserve
+org.eclipse.jdt.core.compiler.compliance=17
+org.eclipse.jdt.core.compiler.debug.lineNumber=generate
+org.eclipse.jdt.core.compiler.debug.localVariable=generate
+org.eclipse.jdt.core.compiler.debug.sourceFile=generate
+org.eclipse.jdt.core.compiler.problem.assertIdentifier=error
+org.eclipse.jdt.core.compiler.problem.enablePreviewFeatures=disabled
+org.eclipse.jdt.core.compiler.problem.enumIdentifier=error
+org.eclipse.jdt.core.compiler.problem.reportPreviewFeatures=warning
+org.eclipse.jdt.core.compiler.release=enabled
+org.eclipse.jdt.core.compiler.source=17

zoo/src/com/example/zoo/domain/Animal.java

@@ -0,0 +1,19 @@
+package com.example.zoo.domain;
+
+abstract public class Animal {
+	protected int legs;
+
+	public Animal(int legs) {
+		this.legs = legs;
+	}
+
+	public int getLegs() {
+		return legs;
+	}
+
+	public void walk() {
+		System.out.println("Animal with %d legs is walking now...".formatted(legs));
+	}
+
+	abstract public void eat();
+}

zoo/src/com/example/zoo/domain/Cat.java

@@ -0,0 +1,35 @@
+package com.example.zoo.domain;
+
+public class Cat extends Animal implements Pet {
+	private String name;
+
+	public Cat() {
+		this("Tekir");
+	}
+
+	public Cat(String name) {
+		super(4);
+		this.name = name;
+	}
+
+	@Override
+	public void setName(String name) {
+		this.name = name;
+	}
+
+	@Override
+	public String getName() {
+		return name;
+	}
+
+	@Override
+	public void play() {
+		System.out.println("%s is playing now...".formatted(name));
+	}
+
+	@Override
+	public void eat() {
+		System.out.println("%s is eating now...".formatted(name));
+	}
+
+}

zoo/src/com/example/zoo/domain/Fish.java

@@ -0,0 +1,37 @@
+package com.example.zoo.domain;
+
+public class Fish extends Animal implements Pet {
+
+	private String name;
+
+	public Fish(String name) {
+		super(0);
+		this.name = name;
+	}
+
+	@Override
+	public void setName(String name) {
+		this.name = name;
+	}
+
+	@Override
+	public String getName() {
+		return name;
+	}
+
+	@Override
+	public void play() {
+		System.out.println("%s is playing now...".formatted(name));
+	}
+
+	@Override
+	public void eat() {
+		System.out.println("%s is eating now...".formatted(name));
+	}
+
+	@Override
+	public void walk() {
+		System.out.println("%s is swimming now...".formatted(name));
+	}
+
+}

zoo/src/com/example/zoo/domain/Pet.java

@@ -0,0 +1,7 @@
+package com.example.zoo.domain;
+
+public abstract interface Pet {
+	abstract public void setName(String name);
+	abstract String getName();
+	public void play();
+}

zoo/src/com/example/zoo/domain/Spider.java

@@ -0,0 +1,14 @@
+package com.example.zoo.domain;
+
+public class Spider extends Animal {
+
+	public Spider() {
+		super(8);
+	}
+
+	@Override
+	public void eat() {
+		System.out.println("Spider is eating now...");
+	}
+
+}