Merge pull request mouredev#6317 from martinbohorquez/java#23

#23 java

Author: kontroldev

Roadmap/23 - SINGLETON/java/martinbohorquez.java

@@ -0,0 +1,71 @@
+public class martinbohorquez {
+    public static void main(String[] args) {
+        Singleton singleton = Singleton.getInstance();
+        Singleton.message();
+        singleton.message();
+        Singleton.message();
+
+        /*
+         * DIFICULTAD EXTRA
+         */
+
+        UserSession session = UserSession.getUserInstance();
+        session.assignUser("1", "Martin Bohorquez", "mbohorquez", "[email protected]");
+        System.out.printf("Usuario: %s, instancia Singleton: %s%n", session.getUserData(), session);
+        session.deleteSession();
+        System.out.printf("Usuario: %s, instancia Singleton: %s%n", session.getUserData(), session);
+
+
+    }
+
+    private static class Singleton {
+        private static Singleton instance;
+
+        private Singleton() {
+        }
+
+        public static Singleton getInstance() {
+            instance = (instance == null) ? new Singleton() : instance;
+            return instance;
+        }
+
+        public static void message() {
+            System.out.printf("Soy un Singleton: %s%n", instance);
+        }
+    }
+
+    private static class UserSession {
+        private static UserSession instance;
+
+        private String id;
+        private String name;
+        private String userName;
+        private String email;
+
+        private UserSession() {
+        }
+
+        public static UserSession getUserInstance() {
+            instance = (instance == null) ? new UserSession() : instance;
+            return instance;
+        }
+
+        public void assignUser(String id, String name, String userName, String email) {
+            this.id = id;
+            this.name = name;
+            this.userName = userName;
+            this.email = email;
+        }
+
+        public String getUserData() {
+            return "{id='" + id + "', name='" + name + "', userName='" + userName + "', email='" + email + "'}";
+        }
+
+        public void deleteSession() {
+            id = null;
+            name = null;
+            userName = null;
+            email = null;
+        }
+    }
+}