Add Flyweight

README.md

@@ -8,4 +8,6 @@ Project that implements some design patterns using Java 13.
 - Decorator
 - State
 - Builder
-- Observer
+- Observer
+- Factory
+- Flyweight

src/flyweight/Annotation.txt

@@ -0,0 +1,29 @@
+###############################
+#         Flyweight           #
+###############################
+
+
+
+
+
+##### Language - EN
+
+- Flyweight helps us to create objects and pass on the same object, if I wanted to play a song with 5 "fa" notes I use the same object,
+that way we save memory.
+
+- Graphical applications generally make use of this pattern, since they have a lot of repeated objects.
+
+- The JVM itself makes use of a Flyweight internally. When you declare an "int", and repeat the same "int" value in several places,
+it always returns the same instance of that number. It is a good example of implementing the standard.
+
+
+
+##### Language - PT-BR
+
+- Flyweight nos ajuda a criar objetos e repassar o mesmo objeto, caso eu queria tocar uma música com 5 notas "fa" eu uso o mesmo objeto,
+dessa forma economizamos memória.
+
+- Aplicações gráficas geralmente fazem uso desse padrão, já que elas tem muito objeto repetido.
+
+- A própria JVM faz uso de um Flyweight internamente. Quando você declara um "int", e repete o mesmo valor de "int" em vários lugares, 
+ela sempre devolve a mesma instância desse número. É um bom exemplo de implementação do padrão.

src/flyweight/FlyweightMain.java

@@ -0,0 +1,32 @@
+package flyweight;
+
+import java.util.Arrays;
+import java.util.List;
+
+public class FlyweightMain {
+
+	public static void main(String[] args) {
+		System.out.println("--------------------------------------------- Begin Test Flyweight");
+
+		MusicalNotes notes = new MusicalNotes();
+
+		// Note = "fa" -> it will be the same object, using Flyweight will always return the same object, 
+		// so there is no need to instantiate many objects at once.
+		List<Note> music = Arrays.asList(
+				notes.getNote("do"),
+				notes.getNote("re"),
+				notes.getNote("mi"),
+				notes.getNote("fa"),
+				notes.getNote("fa"),
+				notes.getNote("fa"));
+
+		System.out.println("Array music: " + music);// Fa@ ..... will point to the same instantiated object
+
+		Piano piano = new Piano();
+
+		piano.play(music);//unmute your computer to listen to the music
+
+		System.out.println("--------------------------------------------- End Test Flyweight");
+	}
+
+}

src/flyweight/MusicalNotes.java

@@ -0,0 +1,34 @@
+package flyweight;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import flyweight.notes.Do;
+import flyweight.notes.Fa;
+import flyweight.notes.La;
+import flyweight.notes.Mi;
+import flyweight.notes.Re;
+import flyweight.notes.Si;
+import flyweight.notes.Sol;
+
+public class MusicalNotes {
+
+	private static Map<String, Note> notes = new HashMap<>();
+
+	// static constructor of the class, it is executed when the JVM loads that class. It runs only once.
+	static {
+		notes.put("do", new Do());
+		notes.put("re", new Re());
+		notes.put("mi", new Mi());
+		notes.put("fa", new Fa());
+		notes.put("sol", new Sol());
+		notes.put("la", new La());
+		notes.put("si", new Si());
+	}
+
+	// If I want to get a note, the method returns the same instance of that note, so there is no need to instantiate X objects of the same type.
+	public Note getNote(String name) {
+		return notes.get(name);
+	}
+
+}

src/flyweight/Note.java

@@ -0,0 +1,7 @@
+package flyweight;
+
+public interface Note {
+
+	public String simbol();
+
+}

src/flyweight/Piano.java

@@ -0,0 +1,22 @@
+package flyweight;
+
+import java.util.List;
+
+import org.jfugue.player.Player;
+
+public class Piano implements PlayMusic {
+
+	public void play(List<Note> music) {
+		Player player = new Player(); // For player -> Example String: "D D E F F"
+
+		StringBuilder musicInNote = new StringBuilder();
+		for (Note note : music) {
+			musicInNote.append(note.simbol() + " ");
+		}
+
+		System.out.println("Music Notes: " + musicInNote.toString());
+
+		player.play(musicInNote.toString());
+	}
+
+}

src/flyweight/PlayMusic.java

@@ -0,0 +1,9 @@
+package flyweight;
+
+import java.util.List;
+
+public interface PlayMusic {
+
+	public void play(List<Note> music);
+
+}

src/flyweight/notes/Do.java

@@ -0,0 +1,12 @@
+package flyweight.notes;
+
+import flyweight.Note;
+
+public class Do implements Note {
+
+	@Override
+	public String simbol() {
+		return "C";
+	}
+
+}

src/flyweight/notes/Fa.java

@@ -0,0 +1,12 @@
+package flyweight.notes;
+
+import flyweight.Note;
+
+public class Fa implements Note {
+
+	@Override
+	public String simbol() {
+		return "F";
+	}
+
+}

src/flyweight/notes/La.java

@@ -0,0 +1,12 @@
+package flyweight.notes;
+
+import flyweight.Note;
+
+public class La implements Note {
+
+	@Override
+	public String simbol() {
+		return "A";
+	}
+
+}

src/flyweight/notes/Mi.java

@@ -0,0 +1,12 @@
+package flyweight.notes;
+
+import flyweight.Note;
+
+public class Mi implements Note {
+
+	@Override
+	public String simbol() {
+		return "E";
+	}
+
+}

src/flyweight/notes/Re.java

@@ -0,0 +1,12 @@
+package flyweight.notes;
+
+import flyweight.Note;
+
+public class Re implements Note {
+
+	@Override
+	public String simbol() {
+		return "D";
+	}
+
+}

src/flyweight/notes/Si.java

@@ -0,0 +1,12 @@
+package flyweight.notes;
+
+import flyweight.Note;
+
+public class Si implements Note {
+
+	@Override
+	public String simbol() {
+		return "B";
+	}
+
+}

src/flyweight/notes/Sol.java

@@ -0,0 +1,12 @@
+package flyweight.notes;
+
+import flyweight.Note;
+
+public class Sol implements Note {
+
+	@Override
+	public String simbol() {
+		return "G";
+	}
+
+}