Fawad Rafi Submission

java/build.gradle

@@ -1,5 +1,3 @@
-
-
 apply plugin: 'java'
 
 sourceCompatibility = 1.8
@@ -11,7 +9,8 @@ repositories {
 }
 
 dependencies {
-    testCompile 'junit:junit:4.12'
+	compile 'org.springframework.boot:spring-boot-starter:1.2.7.RELEASE'
+	testCompile 'junit:junit:4.12'
 }
 
 task wrapper(type: Wrapper) {

java/src/main/java/com/elsevier/education/Exercise1.java

@@ -1,42 +1,61 @@
 package com.elsevier.education;
 
+import java.util.HashSet;
 import java.util.Set;
 
-/**
-
-TODO: Make this class immutable.
-
-*/
 public class Exercise1 {
 
-	public static class Person {
-
-		private Set<String> phoneNumbers;
-		private String firstName;
-		private String lastName;
-
-		public Person() {
+	/**
+	 * Prevent the class from being extended
+	 * @author frafi
+	 *
+	 */
+	public final static class Person {
+		/**
+		 * All member fields should be marked final so they can only be
+		 * modified inside a constructor.
+		 */
+		private final Set<String> phoneNumbers;
+		private final String firstName;
+		private final String lastName;
+
+		/**
+		 * Remove no-arguments constructor and instead provide a parameterized constructor
+		 *
+		 */
+		public Person(String firstName, String lastName, Set<String> phoneNumbers) {
+			this.firstName = firstName;
+			this.lastName = lastName;
+			this.phoneNumbers = phoneNumbers;
 		}
 
+		/**
+		 * Provider getter only for phone numbers collection, no setter.
+		 * Also provide a deep copy of the phone numbers.
+		 * @return Collection of unique phone numbers
+		 */
 		public Set<String> getPhoneNumbers() {
-			return phoneNumbers;
-		}
-		public void setPhoneNumbers(Set<String> newPhoneNumbers) {
-			phoneNumbers = newPhoneNumbers;
+			HashSet<String> retVal = new HashSet<String>(phoneNumbers.size());
+			for(String phone : phoneNumbers) {
+				retVal.add(new String(phone));
+			}
+			return retVal;
 		}
 
+		/**
+		 * Provider getter only for first name, no setter
+		 * @return First Name
+		 */
 		public String getFirstName() {
 			return firstName;
 		}
-		public void setFirstName(String newName) {
-			firstName = newName;
-		}
 
+		/**
+		 * Provider getter only for last name, no setter
+		 * @return Last Name
+		 */
 		public String getLastName() {
 			return lastName;
 		}
-		public void setLastName(String newName) {
-			lastName = newName;
-		}
 	}
 }

java/src/main/java/com/elsevier/education/Exercise2.java

@@ -1,17 +1,19 @@
 package com.elsevier.education;
 
-/**
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+import org.springframework.beans.factory.annotation.Qualifier;
 
-TODO refactor the Car to use dependency injection of the engine
-TODO allow use of either a gas engine or electric engine (create an appropriate abstraction)
-TODO make sure we have no-op implementations of the gas engine and electric engine
-
-*/
 public class Exercise2 {
-
 	public static class Car {
 
-		private GasEngine engine = new GasEngine();
+		/**
+		 * Automatically wire the engine using type (Interface Engine).
+		 * Use a qualifier because there may be multiple classes implementing that interface. 
+		 */
+		@Autowired
+		@Qualifier("gasEngine")
+		private Engine engine;
 
 		public Car() {
 		}
@@ -20,8 +22,35 @@ public void moveForward() {
 			engine.spinWheels();
 		}
 	}
-
-	public static class GasEngine {
+
+	/**
+	 * Declare interface for all engines. This allows us to depend on an interface instead of a class. 
+	 */
+	public static interface Engine {
+		void spinWheels();
+	}
+
+	/**
+	 * Gas engine implements Engine interface.
+	 * Assign unique name to this implementation. Change qualifier to electricEngine if you want to use a different engine. 
+	 */
+	@Component
+	@Qualifier("gasEngine")
+	public static class GasEngine implements Engine {
+		public void spinWheels() {
+			// no-op for now
+		}
+	}
+
+	/**
+	 * Electric Engine also implements Engine interface.
+	 * Assign unique name to this implementation.
+	 * @author frafi
+	 *
+	 */
+	@Component
+	@Qualifier("electricEngine")
+	public static class EletricEngine implements Engine {
 		public void spinWheels() {
 			// no-op for now
 		}

java/src/main/java/com/elsevier/education/Exercise3.java

@@ -1,27 +1,21 @@
 package com.elsevier.education;
 
-import java.util.*;
-
-/**
-
-TODO Examine the failing test case for this class.
- We should be able to call people.add() twice but end with only one object in it.
- We can test with "gradlew test"
-
-*/
 public class Exercise3 {
 
 	public static class Person {
 
-		private static Random generator = new java.util.Random();
 		private Integer id;
 
 		public Person(int newId) {
 			id = newId;
 		}
 
+		/**
+		 * Hash code should not be unique for every instance of Person. 
+		 * It should be depend on internal state and return the same hash for all persons with same ID. 
+		 */
 		public int hashCode() {
-			return id * generator.nextInt();
+			return id;
 		}
 
 		public boolean equals(Object other) {

java/src/main/java/com/elsevier/education/Exercise4.java

@@ -1,25 +1,31 @@
 package com.elsevier.education;
 
 /**
-
-TODO Is Counter thread-safe? If so, why, and if not, how can we fix it?
-
+Counter is not thread-safe. This is because 2 or more threads can simultaneously invoke incremement()
+and resetCount() methods that modify the count instance variable. 
+This can be fixed by converting these 2 methods into synchronized methods. 
 */
 public class Exercise4 {
-
 	public static class Counter {
 
 		private int count = 0;
 
-		public int increment() {
+		/**
+		 * Allows only one thread at a time to increment the count
+		 * @return updated counter
+		 */
+		public synchronized int increment() {
 			return ++count;
 		}
 
 		public int getCount() {
 			return count;
 		}
 
-		public void resetCount() {
+		/**
+		 * Allows only one thread at a time to reset the count
+		 */
+		public synchronized void resetCount() {
 			count = 0;
 		}
 

java/src/main/java/com/elsevier/education/Exercise5.java

@@ -1,20 +1,44 @@
 package com.elsevier.education;
 
-/**
-
-TODO: Turn the "Singleton" class into an actual singleton. The main() method should still call .doSomething().
-
-*/
 public class Exercise5 {
 
 	public static class Singleton {
-		public void doSomething() {
-			System.out.println("Doing something....");
+
+		/**
+		 * Class-level field that could be accessed by multiple threads concurrently
+		 */
+		private static volatile Singleton _instance = null;
+
+		/**
+		 * Create private constructor to prevent new operator being invoked on this class
+		 */
+		private Singleton() {
+		}
+
+		/**
+		 * Performs lazy-instantiation of singleton instance to conserve resources. 
+		 * Prevents multiple threads from simultaneously instantiating the class-level field.
+		 * @return Singleton instance
+		 */
+		public static Singleton getInstance() {
+	        if (_instance == null) {
+                // Lock the entire class in JVM and allow only one thread into this block
+	            synchronized(Singleton.class) {
+	                if (_instance == null) {
+	                    _instance = new Singleton();
+	                }
+	            }
+	        }
+	        return _instance;
 	    }
+
+		public void doSomeThing() {
+			System.out.println("Doing something....");
+		}
 	}
-		
+
 	public static void main(String a[]){
-		Singleton st = new Singleton();
+		Singleton st = Singleton.getInstance();
 		st.doSomeThing();
 	}
 }

javascript/SMART-on-FHIR/SmartFHIR/.editorconfig

@@ -0,0 +1,13 @@
+# Editor configuration, see http://editorconfig.org
+root = true
+
+[*]
+charset = utf-8
+indent_style = space
+indent_size = 2
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.md]
+max_line_length = off
+trim_trailing_whitespace = false

javascript/SMART-on-FHIR/SmartFHIR/.gitignore

@@ -0,0 +1,39 @@
+# See http://help.github.com/ignore-files/ for more about ignoring files.
+
+# compiled output
+/dist
+/tmp
+/out-tsc
+
+# dependencies
+/node_modules
+
+# IDEs and editors
+/.idea
+.project
+.classpath
+.c9/
+*.launch
+.settings/
+*.sublime-workspace
+
+# IDE - VSCode
+.vscode/*
+!.vscode/settings.json
+!.vscode/tasks.json
+!.vscode/launch.json
+!.vscode/extensions.json
+
+# misc
+/.sass-cache
+/connect.lock
+/coverage
+/libpeerconnection.log
+npm-debug.log
+yarn-error.log
+testem.log
+/typings
+
+# System Files
+.DS_Store
+Thumbs.db

javascript/SMART-on-FHIR/SmartFHIR/README.md

@@ -0,0 +1,27 @@
+# SmartFHIR
+
+This project was generated with [Angular CLI](https://github.com/angular/angular-cli) version 6.2.5.
+
+## Development server
+
+Run `ng serve` for a dev server. Navigate to `http://localhost:4200/`. The app will automatically reload if you change any of the source files.
+
+## Code scaffolding
+
+Run `ng generate component component-name` to generate a new component. You can also use `ng generate directive|pipe|service|class|guard|interface|enum|module`.
+
+## Build
+
+Run `ng build` to build the project. The build artifacts will be stored in the `dist/` directory. Use the `--prod` flag for a production build.
+
+## Running unit tests
+
+Run `ng test` to execute the unit tests via [Karma](https://karma-runner.github.io).
+
+## Running end-to-end tests
+
+Run `ng e2e` to execute the end-to-end tests via [Protractor](http://www.protractortest.org/).
+
+## Further help
+
+To get more help on the Angular CLI use `ng help` or go check out the [Angular CLI README](https://github.com/angular/angular-cli/blob/master/README.md).