diff --git a/core-java-modules/core-java-lang-oop/src/main/java/com/baeldung/hexagon/ConstantTaxRateRepository.java b/core-java-modules/core-java-lang-oop/src/main/java/com/baeldung/hexagon/ConstantTaxRateRepository.java
new file mode 100644
index 0000000000..fb7b2963c0
--- /dev/null
+++ b/core-java-modules/core-java-lang-oop/src/main/java/com/baeldung/hexagon/ConstantTaxRateRepository.java
@@ -0,0 +1,11 @@
+package com.baeldung.hexagon;
+
+public class ConstantTaxRateRepository implements TaxRateRepository{
+
+	private static final double TAX_RATE = 0.13d;
+	
+	@Override
+	public double getRate() {
+		return TAX_RATE;
+	}
+}
diff --git a/core-java-modules/core-java-lang-oop/src/main/java/com/baeldung/hexagon/TaxCalculator.java b/core-java-modules/core-java-lang-oop/src/main/java/com/baeldung/hexagon/TaxCalculator.java
new file mode 100644
index 0000000000..6a2f875f5b
--- /dev/null
+++ b/core-java-modules/core-java-lang-oop/src/main/java/com/baeldung/hexagon/TaxCalculator.java
@@ -0,0 +1,17 @@
+package com.baeldung.hexagon;
+
+public class TaxCalculator implements TaxService {
+
+	private TaxRateRepository taxRateRepository;
+
+	public TaxCalculator(TaxRateRepository repository) {
+		super();
+		taxRateRepository = repository;
+	}
+
+	@Override
+	public double calculateTax(Double amount) {
+		return amount * taxRateRepository.getRate();
+	}
+	
+}
diff --git a/core-java-modules/core-java-lang-oop/src/main/java/com/baeldung/hexagon/TaxFactory.java b/core-java-modules/core-java-lang-oop/src/main/java/com/baeldung/hexagon/TaxFactory.java
new file mode 100644
index 0000000000..d35c3fca2e
--- /dev/null
+++ b/core-java-modules/core-java-lang-oop/src/main/java/com/baeldung/hexagon/TaxFactory.java
@@ -0,0 +1,13 @@
+package com.baeldung.hexagon;
+
+public class TaxFactory {
+	
+	public static TaxService getTaxService() {
+		return new TaxCalculator(getTaxRepository());
+	}
+	
+	public static TaxRateRepository getTaxRepository() {
+		return new ConstantTaxRateRepository();
+	}
+
+}
diff --git a/core-java-modules/core-java-lang-oop/src/main/java/com/baeldung/hexagon/TaxRateRepository.java b/core-java-modules/core-java-lang-oop/src/main/java/com/baeldung/hexagon/TaxRateRepository.java
new file mode 100644
index 0000000000..ca1623a4ef
--- /dev/null
+++ b/core-java-modules/core-java-lang-oop/src/main/java/com/baeldung/hexagon/TaxRateRepository.java
@@ -0,0 +1,6 @@
+package com.baeldung.hexagon;
+
+public interface TaxRateRepository {
+
+	public double getRate();
+}
diff --git a/core-java-modules/core-java-lang-oop/src/main/java/com/baeldung/hexagon/TaxService.java b/core-java-modules/core-java-lang-oop/src/main/java/com/baeldung/hexagon/TaxService.java
new file mode 100644
index 0000000000..a6652d81ff
--- /dev/null
+++ b/core-java-modules/core-java-lang-oop/src/main/java/com/baeldung/hexagon/TaxService.java
@@ -0,0 +1,7 @@
+package com.baeldung.hexagon;
+
+public interface TaxService {
+
+	public double calculateTax(Double amount);
+	
+}
diff --git a/core-java-modules/core-java-lang-oop/src/main/java/com/baeldung/hexagon/TestTaxUser.java b/core-java-modules/core-java-lang-oop/src/main/java/com/baeldung/hexagon/TestTaxUser.java
new file mode 100644
index 0000000000..82ab5fafa8
--- /dev/null
+++ b/core-java-modules/core-java-lang-oop/src/main/java/com/baeldung/hexagon/TestTaxUser.java
@@ -0,0 +1,9 @@
+package com.baeldung.hexagon;
+
+public class TestTaxUser {
+
+	public double calculateTax(Double amount) {
+		return TaxFactory.getTaxService().calculateTax(amount);
+	}
+
+}