Adding decorator pattern

patterns/decorator/Coffee.java

@@ -0,0 +1,13 @@
+package patterns.decorator;
+
+
+public abstract class Coffee {
+
+    String description = "Unknown Coffee";
+
+    public String getDescription() {
+        return description;
+    }
+
+    public abstract double cost();
+}

patterns/decorator/CoffeeDecorator.java

@@ -0,0 +1,5 @@
+package patterns.decorator;
+
+public abstract class CoffeeDecorator extends Coffee {
+    public abstract String getDescription();
+}

patterns/decorator/Espresso.java

@@ -0,0 +1,14 @@
+package patterns.decorator;
+
+public class Espresso extends Coffee {
+
+    public Espresso() {
+        description = "Espresso";
+    }
+
+    @Override
+    public double cost() {
+        return 1.99;
+    }
+
+}

patterns/decorator/WithMilk.java

@@ -0,0 +1,20 @@
+package patterns.decorator;
+
+public class WithMilk extends CoffeeDecorator {
+
+    Coffee coffee;
+
+    public WithMilk(Coffee coffee) {
+        this.coffee = coffee;
+    }
+
+    @Override
+    public String getDescription() {
+        return coffee.getDescription() + ", Milk";
+    }
+
+    @Override
+    public double cost() {
+        return coffee.cost() + .50;
+    }
+}

patterns/decorator/WithSugar.java

@@ -0,0 +1,20 @@
+package patterns.decorator;
+
+public class WithSugar extends CoffeeDecorator {
+
+    Coffee coffee;
+
+    public WithSugar(Coffee coffee) {
+        this.coffee = coffee;
+    }
+
+    @Override
+    public String getDescription() {
+        return coffee.getDescription() + ", Sugar";
+    }
+
+    @Override
+    public double cost() {
+        return coffee.cost() + .25;
+    }
+}

patterns/decorator/base/Main.java

@@ -0,0 +1,26 @@
+package patterns.decorator.base;
+
+import patterns.decorator.Coffee;
+import patterns.decorator.Espresso;
+import patterns.decorator.WithMilk;
+import patterns.decorator.WithSugar;
+
+public class Main {
+    public static void main(String[] args) {
+
+        Coffee espresso = new Espresso();
+//        printCoffee(espresso);
+
+        espresso = new WithMilk(espresso);
+//        printCoffee(espresso);
+
+        espresso = new WithSugar(espresso);
+        espresso = new WithSugar(espresso);
+        printCoffee(espresso);
+
+    }
+
+    private static void printCoffee(Coffee c) {
+        System.out.println("Cost: " + c.cost() + ", Description: " + c.getDescription());
+    }
+}

observer/CurrentConditionsDisplay.java → patterns/observer/CurrentConditionsDisplay.java

@@ -1,26 +1,26 @@
-package patterns.observer;
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class CurrentConditionsDisplay implements Observer {
-
-    private int temp;
-    private int humidity;
-
-    public CurrentConditionsDisplay(Subject weatherStation) {
-        weatherStation.registerObserver(this);
-    }
-
-    @Override
-    public void update(int temp, int humidity) {
-        this.temp = temp;
-        this.humidity = humidity;
-        displayCurrent();
-    }
-
-    public void displayCurrent() {
-        System.out.println("Current Temperature: " + temp);
-        System.out.println("Current Humidity: " + humidity);
-    }
-}
+package patterns.observer;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class CurrentConditionsDisplay implements Observer {
+
+    private int temp;
+    private int humidity;
+
+    public CurrentConditionsDisplay(Subject weatherStation) {
+        weatherStation.registerObserver(this);
+    }
+
+    @Override
+    public void update(int temp, int humidity) {
+        this.temp = temp;
+        this.humidity = humidity;
+        displayCurrent();
+    }
+
+    public void displayCurrent() {
+        System.out.println("Current Temperature: " + temp);
+        System.out.println("Current Humidity: " + humidity);
+    }
+}

observer/ForecastDisplay.java → patterns/observer/ForecastDisplay.java

@@ -1,32 +1,32 @@
-package patterns.observer;
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class ForecastDisplay implements Observer {
-
-    private List<Integer> tempHistory;
-    private List<Integer> humidityHistory;
-
-    public ForecastDisplay(Subject weatherStation) {
-        tempHistory = new ArrayList<>();
-        humidityHistory = new ArrayList<>();
-        weatherStation.registerObserver(this);
-    }
-
-    @Override
-    public void update(int temp, int humidity) {
-        this.tempHistory.add(temp);
-        this.humidityHistory.add(temp);
-        display7DayHistory();
-    }
-
-    public void display7DayHistory() {
-        //Print Last 7 days History of Temperature and Humidity
-        System.out.println("Temperature History: " +
-                tempHistory.subList(Math.max(tempHistory.size() - 7, 0), tempHistory.size()));
-        System.out.println("Humidity History: " +
-                humidityHistory.subList(Math.max(humidityHistory.size() - 7, 0), humidityHistory.size()));
-
-    }
-}
+package patterns.observer;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class ForecastDisplay implements Observer {
+
+    private List<Integer> tempHistory;
+    private List<Integer> humidityHistory;
+
+    public ForecastDisplay(Subject weatherStation) {
+        tempHistory = new ArrayList<>();
+        humidityHistory = new ArrayList<>();
+        weatherStation.registerObserver(this);
+    }
+
+    @Override
+    public void update(int temp, int humidity) {
+        this.tempHistory.add(temp);
+        this.humidityHistory.add(temp);
+        display7DayHistory();
+    }
+
+    public void display7DayHistory() {
+        //Print Last 7 days History of Temperature and Humidity
+        System.out.println("Temperature History: " +
+                tempHistory.subList(Math.max(tempHistory.size() - 7, 0), tempHistory.size()));
+        System.out.println("Humidity History: " +
+                humidityHistory.subList(Math.max(humidityHistory.size() - 7, 0), humidityHistory.size()));
+
+    }
+}

observer/Main.java → patterns/observer/Main.java

@@ -1,33 +1,33 @@
-package patterns.observer;
-
-import java.util.Random;
-
-public class Main {
-
-    public static void main(String[] args) throws InterruptedException {
-        //Create the data object (publisher / topic)
-        WeatherStation weatherStation = new WeatherStation();
-
-        //Create and register our displays (observers / subscribers)
-        CurrentConditionsDisplay currentConditionsDisplay =
-                new CurrentConditionsDisplay(weatherStation);
-        ForecastDisplay forecastDisplay = new ForecastDisplay(weatherStation);
-
-        //Simulate updates
-        for (int i = 0; i < 5; i++) {
-            System.out.println("\n--- Update " + i + " ---");
-
-            int randomTemp = getRandomint(-50, 40);
-            int randomHumidity = getRandomint(0, 100);
-
-            weatherStation.measurementsChanged(randomTemp, randomHumidity);
-
-            Thread.sleep(1000);
-        }
-    }
-
-    private static int getRandomint(int min, int max) {
-        Random rand = new Random();
-        return rand.nextInt(max + 1 - min) + min;
-    }
-}
+package patterns.observer;
+
+import java.util.Random;
+
+public class Main {
+
+    public static void main(String[] args) throws InterruptedException {
+        //Create the data object (publisher / topic)
+        WeatherStation weatherStation = new WeatherStation();
+
+        //Create and register our displays (observers / subscribers)
+        CurrentConditionsDisplay currentConditionsDisplay =
+                new CurrentConditionsDisplay(weatherStation);
+        ForecastDisplay forecastDisplay = new ForecastDisplay(weatherStation);
+
+        //Simulate updates
+        for (int i = 0; i < 5; i++) {
+            System.out.println("\n--- Update " + i + " ---");
+
+            int randomTemp = getRandomint(-50, 40);
+            int randomHumidity = getRandomint(0, 100);
+
+            weatherStation.measurementsChanged(randomTemp, randomHumidity);
+
+            Thread.sleep(1000);
+        }
+    }
+
+    private static int getRandomint(int min, int max) {
+        Random rand = new Random();
+        return rand.nextInt(max + 1 - min) + min;
+    }
+}

observer/Observer.java → patterns/observer/Observer.java

@@ -1,5 +1,5 @@
-package patterns.observer;
-
-public interface Observer {
-    public void update(int temp, int humidity);
-}
+package patterns.observer;
+
+public interface Observer {
+    public void update(int temp, int humidity);
+}

observer/Subject.java → patterns/observer/Subject.java

@@ -1,7 +1,7 @@
-package patterns.observer;
-
-public interface Subject {
-    public void registerObserver(Observer o);
-    public void removeObserver(Observer o);
-    public void notifyObservers();
-}
+package patterns.observer;
+
+public interface Subject {
+    public void registerObserver(Observer o);
+    public void removeObserver(Observer o);
+    public void notifyObservers();
+}