diff --git a/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/AbstractFactory.java b/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/AbstractFactory.java
new file mode 100644
index 0000000000..46d97d1a15
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/AbstractFactory.java
@@ -0,0 +1,6 @@
+package com.baeldung.designpatterns.creational.abstractfactory;
+
+public interface AbstractFactory {
+    Animal getAnimal(String toyType) ;
+    Color getColor(String colorType);
+}
\ No newline at end of file
diff --git a/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/AbstractPatternDriver.java b/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/AbstractPatternDriver.java
new file mode 100644
index 0000000000..7ab166e16a
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/AbstractPatternDriver.java
@@ -0,0 +1,18 @@
+package com.baeldung.designpatterns.creational.abstractfactory;
+
+public class AbstractPatternDriver {
+    public static void main(String[] args) {
+        AbstractFactory abstractFactory;
+        
+        //creating a brown toy dog
+        abstractFactory = FactoryProvider.getFactory("Toy");
+        Animal toy = abstractFactory.getAnimal("Dog");
+        
+        abstractFactory = FactoryProvider.getFactory("Color");
+        Color color = abstractFactory.getColor("Brown");
+        
+        String result = "A " + toy.getType() + " with " + color.getColor() + " color " + toy.makeSound();
+        
+        System.out.println(result);
+    }
+}
diff --git a/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/Animal.java b/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/Animal.java
new file mode 100644
index 0000000000..59c1336053
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/Animal.java
@@ -0,0 +1,6 @@
+package com.baeldung.designpatterns.creational.abstractfactory;
+
+public interface Animal {
+    String getType();
+    String makeSound();
+}
\ No newline at end of file
diff --git a/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/AnimalFactory.java b/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/AnimalFactory.java
new file mode 100644
index 0000000000..49583c3a98
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/AnimalFactory.java
@@ -0,0 +1,21 @@
+package com.baeldung.designpatterns.creational.abstractfactory;
+
+public class AnimalFactory implements AbstractFactory {
+
+    @Override
+    public Animal getAnimal(String animalType) {
+        if ("Dog".equalsIgnoreCase(animalType)) {
+            return new Dog();
+        } else if ("Duck".equalsIgnoreCase(animalType)) {
+            return new Duck();
+        }
+
+        return null;
+    }
+
+    @Override
+    public Color getColor(String color) {
+        throw new UnsupportedOperationException();
+    }
+
+}
diff --git a/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/Brown.java b/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/Brown.java
new file mode 100644
index 0000000000..f251285ebf
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/Brown.java
@@ -0,0 +1,10 @@
+package com.baeldung.designpatterns.creational.abstractfactory;
+
+public class Brown implements Color {
+
+    @Override
+    public String getColor() {
+        return "brown";
+    }
+
+}
diff --git a/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/Color.java b/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/Color.java
new file mode 100644
index 0000000000..897bb71f38
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/Color.java
@@ -0,0 +1,5 @@
+package com.baeldung.designpatterns.creational.abstractfactory;
+
+public interface Color {
+    String getColor();
+}
diff --git a/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/ColorFactory.java b/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/ColorFactory.java
new file mode 100644
index 0000000000..8f7559ff27
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/ColorFactory.java
@@ -0,0 +1,21 @@
+package com.baeldung.designpatterns.creational.abstractfactory;
+
+public class ColorFactory implements AbstractFactory {
+
+    @Override
+    public Color getColor(String colorType) {
+        if ("Brown".equalsIgnoreCase(colorType)) {
+            return new Brown();
+        } else if ("White".equalsIgnoreCase(colorType)) {
+            return new White();
+        }
+
+        return null;
+    }
+
+    @Override
+    public Animal getAnimal(String toyType) {
+        throw new UnsupportedOperationException();
+    }
+
+}
diff --git a/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/Dog.java b/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/Dog.java
new file mode 100644
index 0000000000..002b5665d3
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/Dog.java
@@ -0,0 +1,15 @@
+package com.baeldung.designpatterns.creational.abstractfactory;
+
+public class Dog implements Animal {
+
+    @Override
+    public String getType() {
+        return "Dog";
+    }
+
+    @Override
+    public String makeSound() {
+        return "Barks";
+    }
+
+}
diff --git a/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/Duck.java b/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/Duck.java
new file mode 100644
index 0000000000..5603ad6eee
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/Duck.java
@@ -0,0 +1,15 @@
+package com.baeldung.designpatterns.creational.abstractfactory;
+
+public class Duck implements Animal {
+
+    @Override
+    public String getType() {
+        return "Duck";
+    }
+
+    @Override
+    public String makeSound() {
+        return "Squeks";
+    }
+
+}
diff --git a/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/FactoryProvider.java b/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/FactoryProvider.java
new file mode 100644
index 0000000000..fcbee1e6de
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/FactoryProvider.java
@@ -0,0 +1,15 @@
+package com.baeldung.designpatterns.creational.abstractfactory;
+
+public class FactoryProvider {
+    public static AbstractFactory getFactory(String choice){
+        
+        if("Toy".equalsIgnoreCase(choice)){
+            return new AnimalFactory();
+        }
+        else if("Color".equalsIgnoreCase(choice)){
+            return new ColorFactory();
+        }
+        
+        return null;
+    }
+}
\ No newline at end of file
diff --git a/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/White.java b/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/White.java
new file mode 100644
index 0000000000..62ef8048ea
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/designpatterns/creational/abstractfactory/White.java
@@ -0,0 +1,10 @@
+package com.baeldung.designpatterns.creational.abstractfactory;
+
+public class White implements Color {
+
+    @Override
+    public String getColor() {
+        return "White";
+    }
+
+}
diff --git a/core-java/src/main/java/com/baeldung/designpatterns/creational/builder/BankAccount.java b/core-java/src/main/java/com/baeldung/designpatterns/creational/builder/BankAccount.java
new file mode 100644
index 0000000000..355fa74895
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/designpatterns/creational/builder/BankAccount.java
@@ -0,0 +1,64 @@
+package com.baeldung.designpatterns.creational.builder;
+
+public class BankAccount {
+    private String name;
+    private String accountNumber;
+    private String email;
+    private boolean newsletter;
+
+    //The constructor that takes a builder from which it will create object
+    //the access to this is only provided to builder
+    private BankAccount(BankAccountBuilder builder) {
+        this.name = builder.name;
+        this.accountNumber = builder.accountNumber;
+        this.email = builder.email;
+        this.newsletter = builder.newsletter;
+    }
+    
+    public static class BankAccountBuilder {
+        private String name;
+        private String accountNumber;
+        private String email;
+        private boolean newsletter;
+        
+        //All Mandatory parameters goes with this constructor
+        public BankAccountBuilder(String name, String accountNumber) {
+            this.name = name;
+            this.accountNumber = accountNumber;
+        }
+
+        //setters for optional parameters which returns this same builder
+        //to support fluent design
+        public BankAccountBuilder withEmail(String email) {
+            this.email = email;
+            return this;
+        }
+
+        public BankAccountBuilder wantNewsletter(boolean newsletter) {
+            this.newsletter = newsletter;
+            return this;
+        }
+        
+        //the actual build method that prepares and returns a BankAccount object
+        public BankAccount build() {
+            return new BankAccount(this);
+        }
+    }
+
+    //getters
+    public String getName() {
+        return name;
+    }
+
+    public String getAccountNumber() {
+        return accountNumber;
+    }
+
+    public String getEmail() {
+        return email;
+    }
+
+    public boolean isNewsletter() {
+        return newsletter;
+    }
+}
diff --git a/core-java/src/main/java/com/baeldung/designpatterns/creational/builder/BuilderPatternDriver.java b/core-java/src/main/java/com/baeldung/designpatterns/creational/builder/BuilderPatternDriver.java
new file mode 100644
index 0000000000..d92a70e664
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/designpatterns/creational/builder/BuilderPatternDriver.java
@@ -0,0 +1,16 @@
+package com.baeldung.designpatterns.creational.builder;
+
+public class BuilderPatternDriver {
+    public static void main(String[] args) {
+        BankAccount newAccount = new BankAccount
+          .BankAccountBuilder("Jon", "22738022275")
+          .withEmail("jon@example.com")
+          .wantNewsletter(true)
+          .build();
+
+        System.out.println("Name: " + newAccount.getName());
+        System.out.println("AccountNumber:" + newAccount.getAccountNumber());
+        System.out.println("Email: " + newAccount.getEmail());
+        System.out.println("Want News letter?: " + newAccount.isNewsletter());
+    }
+}
diff --git a/core-java/src/main/java/com/baeldung/designpatterns/creational/factory/FactoryDriver.java b/core-java/src/main/java/com/baeldung/designpatterns/creational/factory/FactoryDriver.java
new file mode 100644
index 0000000000..64ee307bb8
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/designpatterns/creational/factory/FactoryDriver.java
@@ -0,0 +1,16 @@
+package com.baeldung.designpatterns.creational.factory;
+
+public class FactoryDriver {
+    public static void main(String[] args) {
+        Polygon p;
+        PolygonFactory factory = new PolygonFactory();
+        
+        //get the shape which has 4 sides
+        p = factory.getPolygon(4);
+        System.out.println("The shape with 4 sides is a " + p.getType());
+        
+        //get the shape which has 4 sides
+        p = factory.getPolygon(8);
+        System.out.println("The shape with 8 sides is a " + p.getType());
+    }
+}
diff --git a/core-java/src/main/java/com/baeldung/designpatterns/creational/factory/Heptagon.java b/core-java/src/main/java/com/baeldung/designpatterns/creational/factory/Heptagon.java
new file mode 100644
index 0000000000..935fc2f04c
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/designpatterns/creational/factory/Heptagon.java
@@ -0,0 +1,10 @@
+package com.baeldung.designpatterns.creational.factory;
+
+public class Heptagon implements Polygon {
+
+    @Override
+    public String getType() {
+        return "Heptagon";
+    }
+
+}
diff --git a/core-java/src/main/java/com/baeldung/designpatterns/creational/factory/Octagon.java b/core-java/src/main/java/com/baeldung/designpatterns/creational/factory/Octagon.java
new file mode 100644
index 0000000000..fc62302dc8
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/designpatterns/creational/factory/Octagon.java
@@ -0,0 +1,10 @@
+package com.baeldung.designpatterns.creational.factory;
+
+public class Octagon implements Polygon {
+
+    @Override
+    public String getType() {
+        return "Octagon";
+    }
+
+}
diff --git a/core-java/src/main/java/com/baeldung/designpatterns/creational/factory/Pentagon.java b/core-java/src/main/java/com/baeldung/designpatterns/creational/factory/Pentagon.java
new file mode 100644
index 0000000000..65d109b10b
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/designpatterns/creational/factory/Pentagon.java
@@ -0,0 +1,10 @@
+package com.baeldung.designpatterns.creational.factory;
+
+public class Pentagon implements Polygon {
+
+    @Override
+    public String getType() {
+        return "Pentagon";
+    }
+
+}
diff --git a/core-java/src/main/java/com/baeldung/designpatterns/creational/factory/Polygon.java b/core-java/src/main/java/com/baeldung/designpatterns/creational/factory/Polygon.java
new file mode 100644
index 0000000000..8364e546b0
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/designpatterns/creational/factory/Polygon.java
@@ -0,0 +1,5 @@
+package com.baeldung.designpatterns.creational.factory;
+
+public interface Polygon {
+    String getType();
+}
diff --git a/core-java/src/main/java/com/baeldung/designpatterns/creational/factory/PolygonFactory.java b/core-java/src/main/java/com/baeldung/designpatterns/creational/factory/PolygonFactory.java
new file mode 100644
index 0000000000..406f0f5274
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/designpatterns/creational/factory/PolygonFactory.java
@@ -0,0 +1,22 @@
+package com.baeldung.designpatterns.creational.factory;
+
+public class PolygonFactory {
+    public Polygon getPolygon(int numberOfSides) {
+        if(numberOfSides == 3) {
+            return new Triangle();
+        }
+        if(numberOfSides == 4) {
+            return new Square();
+        }
+        if(numberOfSides == 5) {
+            return new Pentagon();
+        }
+        if(numberOfSides == 4) {
+            return new Heptagon();
+        }
+        else if(numberOfSides == 8) {
+            return new Octagon();
+        }
+        return null;
+    }
+}
\ No newline at end of file
diff --git a/core-java/src/main/java/com/baeldung/designpatterns/creational/factory/Square.java b/core-java/src/main/java/com/baeldung/designpatterns/creational/factory/Square.java
new file mode 100644
index 0000000000..805c1c9ae3
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/designpatterns/creational/factory/Square.java
@@ -0,0 +1,10 @@
+package com.baeldung.designpatterns.creational.factory;
+
+public class Square implements Polygon {
+
+    @Override
+    public String getType() {
+        return "Square";
+    }
+
+}
diff --git a/core-java/src/main/java/com/baeldung/designpatterns/creational/factory/Triangle.java b/core-java/src/main/java/com/baeldung/designpatterns/creational/factory/Triangle.java
new file mode 100644
index 0000000000..8a8832d8a1
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/designpatterns/creational/factory/Triangle.java
@@ -0,0 +1,10 @@
+package com.baeldung.designpatterns.creational.factory;
+
+public class Triangle implements Polygon {
+
+    @Override
+    public String getType() {
+        return "Triangle";
+    }
+
+}
diff --git a/core-java/src/main/java/com/baeldung/designpatterns/creational/singleton/Singleton.java b/core-java/src/main/java/com/baeldung/designpatterns/creational/singleton/Singleton.java
new file mode 100644
index 0000000000..1a5ac82c89
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/designpatterns/creational/singleton/Singleton.java
@@ -0,0 +1,13 @@
+package com.baeldung.designpatterns.creational.singleton;
+
+public class Singleton  {    
+    private Singleton() {}
+    
+    private static class SingletonHolder {    
+        public static final Singleton instance = new Singleton();
+    }    
+
+    public static Singleton getInstance() {    
+        return SingletonHolder.instance;    
+    }    
+}
\ No newline at end of file
diff --git a/core-java/src/main/java/com/baeldung/designpatterns/creational/singleton/SingletonDriver.java b/core-java/src/main/java/com/baeldung/designpatterns/creational/singleton/SingletonDriver.java
new file mode 100644
index 0000000000..1955008d3e
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/designpatterns/creational/singleton/SingletonDriver.java
@@ -0,0 +1,8 @@
+package com.baeldung.designpatterns.creational.singleton;
+
+public class SingletonDriver {
+    public static void main(String[] args) {
+        Singleton instance = Singleton.getInstance();
+        System.out.println(instance.toString());
+    }
+}
diff --git a/core-java/src/test/java/com/baeldung/designpatterns/creational/abstractfactory/AbstractPatternIntegrationTest.java b/core-java/src/test/java/com/baeldung/designpatterns/creational/abstractfactory/AbstractPatternIntegrationTest.java
new file mode 100644
index 0000000000..dc02b976a0
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/designpatterns/creational/abstractfactory/AbstractPatternIntegrationTest.java
@@ -0,0 +1,23 @@
+package com.baeldung.designpatterns.creational.abstractfactory;
+
+import static org.junit.Assert.*;
+
+import org.junit.Test;
+
+public class AbstractPatternIntegrationTest {
+    @Test
+    public void givenAbstractFactory_whenGettingObjects_thenSuccessful() {
+        AbstractFactory abstractFactory;
+        
+        //creating a brown toy dog
+        abstractFactory = FactoryProvider.getFactory("Toy");
+        Animal toy = abstractFactory.getAnimal("Dog");
+        
+        abstractFactory = FactoryProvider.getFactory("Color");
+        Color color = abstractFactory.getColor("Brown");
+        
+        String result = "A " + toy.getType() + " with " + color.getColor() + " color " + toy.makeSound();
+        assertEquals("A Dog with brown color Barks", result);
+    }
+
+}
diff --git a/core-java/src/test/java/com/baeldung/designpatterns/creational/builder/BuilderPatternIntegrationTest.java b/core-java/src/test/java/com/baeldung/designpatterns/creational/builder/BuilderPatternIntegrationTest.java
new file mode 100644
index 0000000000..898330b26e
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/designpatterns/creational/builder/BuilderPatternIntegrationTest.java
@@ -0,0 +1,33 @@
+package com.baeldung.designpatterns.creational.builder;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+public class BuilderPatternIntegrationTest {
+    @Test
+    public void whenCreatingObjectThroughBuilder_thenObjectValid() {
+        BankAccount newAccount = new BankAccount
+          .BankAccountBuilder("Jon", "22738022275")
+          .withEmail("jon@example.com")
+          .wantNewsletter(true)
+          .build();
+        
+        assertEquals(newAccount.getName(), "Jon");
+        assertEquals(newAccount.getAccountNumber(), "22738022275");
+        assertEquals(newAccount.getEmail(), "jon@example.com");
+        assertEquals(newAccount.isNewsletter(), true);
+    }
+    
+    @Test
+    public void whenSkippingOptionalParameters_thenObjectValid() {
+        BankAccount newAccount = new BankAccount
+          .BankAccountBuilder("Jon", "22738022275")
+          .build();
+        
+        assertEquals(newAccount.getName(), "Jon");
+        assertEquals(newAccount.getAccountNumber(), "22738022275");
+        assertEquals(newAccount.getEmail(), null);
+        assertEquals(newAccount.isNewsletter(), false);
+    }
+}
diff --git a/core-java/src/test/java/com/baeldung/designpatterns/creational/factory/FactoryIntegrationTest.java b/core-java/src/test/java/com/baeldung/designpatterns/creational/factory/FactoryIntegrationTest.java
new file mode 100644
index 0000000000..ed0419c16d
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/designpatterns/creational/factory/FactoryIntegrationTest.java
@@ -0,0 +1,32 @@
+package com.baeldung.designpatterns.creational.factory;
+
+import static org.junit.Assert.*;
+
+import org.junit.Test;
+
+public class FactoryIntegrationTest {
+
+    @Test
+    public void whenUsingFactoryForSquare_thenCorrectObjectReturned() {
+        Polygon p;
+        PolygonFactory factory = new PolygonFactory();
+        
+        //get the shape which has 4 sides
+        p = factory.getPolygon(4);
+        String result = "The shape with 4 sides is a " + p.getType();
+        
+        assertEquals("The shape with 4 sides is a Square", result);
+    }
+    
+    @Test
+    public void whenUsingFactoryForOctagon_thenCorrectObjectReturned() {
+        Polygon p;
+        PolygonFactory factory = new PolygonFactory();
+        
+        //get the shape which has 4 sides
+        p = factory.getPolygon(8);
+        String result = "The shape with 8 sides is a " + p.getType();
+        
+        assertEquals("The shape with 8 sides is a Octagon", result);
+    }
+}
diff --git a/core-java/src/test/java/com/baeldung/designpatterns/creational/singleton/SingletonIntegrationTest.java b/core-java/src/test/java/com/baeldung/designpatterns/creational/singleton/SingletonIntegrationTest.java
new file mode 100644
index 0000000000..a3d5b7a14d
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/designpatterns/creational/singleton/SingletonIntegrationTest.java
@@ -0,0 +1,26 @@
+package com.baeldung.designpatterns.creational.singleton;
+
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+public class SingletonIntegrationTest {
+
+    @Test
+    /**
+     * Although there is absolutely no way to determine whether
+     * a class is Singleton, in this test case, we will just 
+     * check for two objects if they point to same instance or 
+     * not. We will also check for their hashcode.
+     */
+    public void whenGettingMultipleObjects_thenAllPointToSame() {
+        //first object
+        Singleton obj1 = Singleton.getInstance();
+        
+        //Second object
+        Singleton obj2 = Singleton.getInstance();
+        
+        assertTrue(obj1 == obj2);
+        assertEquals(obj1.hashCode(), obj2.hashCode());
+    }
+
+}