Design Patterns and Principles

Author: turingfly

Java-8/src/designPatternsAndPrinciples/ComposingObjects.java

@@ -2,7 +2,8 @@
 
 /**
  * 
- * @author chengfeili Jun 4, 2017 11:12:31 PM
+ * @author chengfeili 
+ * Jun 4, 2017 11:12:31 PM
  *
  *         In object‐oriented design, we refer to object composition as the
  *         property of constructing a class using references to other classes in

Java-8/src/designPatternsAndPrinciples/DefineFunctionalInterface.java

@@ -2,7 +2,8 @@
 
 /**
  * 
- * @author chengfeili Jun 4, 2017 10:10:08 PM
+ * @author chengfeili 
+ * Jun 4, 2017 10:10:08 PM
  *
  */
 @FunctionalInterface
@@ -15,13 +16,11 @@ interface Run1 extends DefineFunctionalInterface {
 }
 
 // 2. valid, override
-
 interface SprintFaster extends DefineFunctionalInterface {
 	public void sprint(String s);
 }
 
 // 3. valid, neither default and static is abstract
-
 interface Skip extends DefineFunctionalInterface {
 	public default int getHopCount(String s) {
 		return 10;

Java-8/src/designPatternsAndPrinciples/DesingInterface.java

@@ -23,10 +23,8 @@ public static double calculateSpeed(float distance, double time) {
 }
 
 public class DesingInterface implements Fly {
-
 	@Override
 	public int getWingSpan() throws Exception {
-		// TODO Auto-generated method stub
 		return 15;
 	}
 

Java-8/src/designPatternsAndPrinciples/ExtendInterface.java

@@ -19,22 +19,18 @@ interface Run extends Walk {
 }
 
 public class ExtendInterface implements Run {
-
 	@Override
 	public boolean isQuadruped() {
-		// TODO Auto-generated method stub
 		return true;
 	}
 
 	@Override
 	public boolean canHuntWhileRunning() {
-		// TODO Auto-generated method stub
 		return true;
 	}
 
 	@Override
 	public double getMaxSpeed() {
-		// TODO Auto-generated method stub
 		return 100;
 	}
 }

Java-8/src/designPatternsAndPrinciples/FactoryPattern.java

@@ -68,7 +68,6 @@ public static Food getFood(String animalName) {
 		case "polar bear":
 			return new Fish(10);
 		}
-
 		// Good practice to throw an exception if no matching subclass could be
 		// found
 		throw new UnsupportedOperationException("Unsupported animal: " + animalName);

Java-8/src/designPatternsAndPrinciples/ImplementingFunctionalInterfacesWithLambdas.java

@@ -28,7 +28,7 @@
  *	a,d -> d.quack()                ==> (a, d) -> d.quack()
  *	Animal a, Duck d -> d.quack()   ==> (Animal a, Duck d) -> d.quack()
  *
- *	a, b - a.startsWith("a")        ==> (a, b) -> a.startsWith("a")
+ *	a, b -> a.startsWith("a")        ==> (a, b) -> a.startsWith("a")
  *
  *	(when one parameter has a data type listed, though, 
  *	all parameters must provide a data type)
@@ -48,7 +48,6 @@ public Animal(String species, boolean canHop, boolean canSwim) {
 	}
 
 	public Animal(String species2, int age, List<String> favoriteFoods) {
-		// TODO Auto-generated constructor stub
 	}
 
 	public boolean canHop() {
@@ -64,19 +63,18 @@ public String toString() {
 	}
 }
 
+@FunctionalInterface
 interface CheckTrait {
 	public boolean test(Animal a);
 }
 
 public class ImplementingFunctionalInterfacesWithLambdas {
-
 	private static void print(Animal animal, Predicate<Animal> trait) {
 		if (trait.test(animal))
 			System.out.println(animal);
 	}
 
 	public static void main(String[] args) {
-
 		// Java relies on context when  figuring out what lambda expressions mean
 		// a -> a.canHop()    ==>   (Animal a) -> {return a.canHop();}
 		print(new Animal("fish", false, true), a -> a.canHop());

Java-8/src/designPatternsAndPrinciples/OneObjectTakeManyDifferentForms.java

@@ -2,7 +2,8 @@
 
 /**
  * 
- * @author chengfeili Jun 4, 2017 10:52:45 PM
+ * @author chengfeili 
+ * Jun 4, 2017 10:52:45 PM
  * 
  *         If you use a variable to refer to an object, then only the methods or
  *         variables that are part of the variable’s reference type can be
@@ -19,9 +20,7 @@
  *         determines which methods and variables are accessible to the Java
  *         program.
  * 
- * 
  *         --------Casting Object reference--------
- * 
  *         1. Casting an object from a subclass to a superclass doesn’t require
  *         an explicit cast. 
  *         2. Casting an object from a superclass to a
@@ -39,6 +38,7 @@ public boolean hasHair() {
 	}
 }
 
+@FunctionalInterface
 interface HasTail {
 	public boolean isTailStriped();
 }
@@ -60,8 +60,7 @@ public static void main(String[] args) {
 
 		Primate primate = lemur;
 		// OneObjectTakeManyDifferentForms lemur2 = primate; // Does not compile
-		// OneObjectTakeManyDifferentForms lemur2 =
-		// OneObjectTakeManyDifferentForms)primate;
+		// OneObjectTakeManyDifferentForms lemur2 = (OneObjectTakeManyDifferentForms)primate;  // explicit cast
 		System.out.println(primate.hasHair()); // true
 
 	}

Java-8/src/designPatternsAndPrinciples/SingletonPattern3.java

@@ -10,7 +10,6 @@
  */
 // Method 3: Lazy Instantiation. Delay creation of the singleton until the first
 // time the getInstance() method is called:
-
 public class SingletonPattern3 {
 	private static SingletonPattern3 instance;