Programming Cloud Services for Android Handheld Systems

This MOOC describes by example how to connect Android mobile devices to clouds via the use of object-oriented design techniques, Java programming language features, Jetty middleware, Java Servlets, the Java Spring Framework, and cloud computing platforms, such as Google App Engine. Although there will be 10 weeks of lecture material, the required core of the course is six weeks long and can be completed flexibly within the ten week schedule to provide flexibility for students during the summer.

An extended case study project will be used throughout the required core of the MOOC to showcase architectures for communicating with the cloud using HTTP, server-side processing of mobile data using servlets and the Java Spring Framework, and scalable storage of data using no-SQL databases and other platforms. Due to the importance of building secure and scalable mobile/cloud platforms, this MOOC will not only show you how to program handheld systems that talk to the cloud, but how to do so securely, scalably, and efficiently. Security and scalability topics will be woven into discussions of cloud service creation so that students learn, from the start, how to create robust cloud services for mobile devices.

Four weeks of optional lecture material will also be provided for students who would like to gain a deeper understanding of the patterns and frameworks for building cloud infrastructure building. This material will be presented in the context of the open-source JAWS web server, which is implemented in C++ as part of the ACE open-source object-oriented concurrent and networked programming toolkit.

Although the cloud service topics in this course will be taught in the context of connecting mobile devices to the cloud, the concepts are broader and will give students the ability to create the cloud services to support large-scale web applications, such as social networking applications; cloud services for embedded systems, such as the Internet of Things and Industrial Internet; and wearable computing devices, such as Google Glass. 

Note: This course is part of a trans-institution sequence of MOOCs entitled Mobile Cloud Computing with Android

This MOOC and two others, taught by Dr. Adam Porter from the University of Maryland and Dr. Douglas C. Schmidt from Vanderbilt University, have been designed to complement one another as part of the first trans-institution Specialization taught on the Coursera platform. Some of the programming assignments and the course project for these MOOCs will be coordinated. Dr. Porter's MOOC, Programming Mobile Applications for Android Handheld Systems, will be taught first; it focuses on the design and programming of user-facing application components. Dr. Schmidt's MOOC, Programming Mobile Services for Android Handheld Systems, will be taught next; it focuses on middleware systems programming topics, such as synchronous and asynchronous concurrency models, background service processing, structured data management, local inter-process communication and networking. This MOOC introduces the concepts and knowledge needed to connect the user-facing and service-based components, built in the first two courses, to the cloud.

If you just want to take some of the MOOCs in this sequence or take them all in different order you’re certainly welcome to do so, and you’ll still learn a lot. If you take all the MOOCs in this sequence in the order presented, however, you’ll gain a deeper, end-to-end understanding of handheld systems, their applications and services, as well as their integration into the cloud.

The course is organized into the sections outlined below.

Section 1: Talking to the Cloud with HTTP

• Module 1: The HTTP Protocol
  • Introduction
  • What are Communication Protocols?
  • Intro to HTTP
  • Why HTTP?
  • What is a cloud service?
  • HTTP Request Methods
  • HTTP Request Anatomy
  • URLs Query Parameters
  • Mime Types Content Type Header
  • Request Body Encoding
  • HTTP Response Anatomy
  • HTTP Response Codes
  • Cookies
• Module 2: Designing Applications with HTTP Communication
  • Building Cloud Services on HTTP
  • Protocol Layering / HTTP Design Methodologies
  • REST
  • HTTP Polling
  • Push Messaging

Section 2: Building Java Cloud Services

• Module 1: Java Servlets
  • What are Servlets?
  • A First Cloud Service with a Servlet
  • Web.xml
  • Video Servlet Code Walkthrough
  • Video Servlet Test Walkthrough with HttpClient
  • Securely Handling Client Data Avoiding Injection Attacks

• Module 2: Better Abstractions for Building Java Cloud Services
  • Intro to Java Annotations
  • HTTP to Object Marshalling
  • Intro to JSON
  • The Spring Dispatcher Servlet and the Controller Abstraction
  • Intro to Spring Controllers
  • Accepting Client Data with RequestParam Annotations
  • Accepting Client Data with PathVar Annotations
  • Accepting Client Data with RequestBody Annotations and JSON
  • Handling Multipart Data
  • Generating Responses with the ResponseBody Annotation
  • Custom Marshalling with Jackson Annotations Serializers/Deserializers
  • Spring Boot Application Structure
  • Spring Controller Code Walkthrough
  • Spring Controller Test Code Walkthrough
• Module 3: Better Client-side Communication Abstractions
  • Introduction to Retrofit
  • Retrofit Client Code Walkthrough
  • Android Retrofit Client Code Walkthrough
• Module 4: Building Loosely Coupled and Extensible Java Services
  • Spring Dependency Injection Auto-wiring
  • Spring Configuration Annotations
  • Spring Dependency Injection Controller Code Walkthrough
  • Spring Dependency Injection Controller Test Code Walkthrough

Section 3: Building Database-driven Java Cloud Services

• Module 1: Persistent Objects
  • Object to DB Mapping
  • JPA
  • Entities
  • Repositories
  • Understanding SQL Injection Attacks
  • Spring Data Code Walkthrough
• Module 2: RESTful Services for Persistent Objects
  • Spring Data REST
  • Spring Data REST Code Walkthrough

Section 4: Restricting Service Access with User Accounts

• Module 1: Secure HTTP Communication
• Man in the Middle Attacks Public Key Infrastructure
• HTTPS
• Module 2: What was I Saying: Keeping Track of Sessions
  • Sessions
  • Spring Security Overview
  • Spring Security Configuration in Java
  • Building a Custom UserDetailsService
  • Setting up a custom UserDetailsService
  • The Principal
  • Spring Security Role Annotations
  • More Complex Expression-based Pre Post Authorize Annotations
  • Spring Security Controller Code Walkthrough
  • Spring Security Controller Test Code Walkthrough
• Module 3: Authenticating Mobile Clients
  • Stateful Sessions with Cookies Why They Aren't Ideal for Mobile
  • Stateless Sessions with Tokens
  • OAuth 2.0
  • Spring Security OAuth 2.0
  • A Spring OAuth 2.0 Secured Service
  • A Retrofit Oauth 2.0 Client for Password Grants

Section 5: Deploying to the Cloud Scaling

• Module 1: General Scaling Strategies
  • Stateless vs. Stateful Applications
  • Horizontal Scaling
  • Auto-scaling Horizontally
  • Caching
  • Offloading to Cloud Provider Services
  • Asynchronous IO in Controllers
• Module 2: Scaling Up Data Storage
  • NoSQL Databases
  • Optimizing for Key-based Lookups
  • Optimizing for Reads vs. Writes
  • Contention Sharding
  • Mongo DB
  • Spring Data Mongo DB
  • Database as a Service
  • Amazon Dynamo
  • Spring Data Dynamo DB
  • App Engine Big Table
• Module 3: Automating Packaging Deployment
  • Deploying to Infrastructure as a Service
  • Deploying to Amazon EC2
  • Packaging Web Applications into WAR files
  • Adapting Spring Boot Applications for Google App Engine
  • Deploying to App Engine
• Module 4: Performance Testing
  • Intro to Cloud Service Performance Testing
  • Apache JMeter
  • Building Realistic Tests

Section 6: Patterns and Frameworks for Concurrent and Networked Server Software [Optional Material]

• Module 1: Introduction to the Web Server Case Study
  • Applying Patterns and Frameworks to Concurrent and Networked Software
  • Overview of JAWS Web Server Case Study: Part 1
  • Overview of JAWS Web Server Case Study: Part 2
  • Overview of JAWS Web Server Case Study: Part 3
• Module 2: Patterns and Frameworks for Service Access and Communication
  • Accidental Complexities with the Sockets API
  • The Wrapper Facade Pattern
  • ACE C++ Socket Wrapper Facades
  • Applying the ACE Wrapper Facades to a Web Client and Server
• Module 3: Patterns and Frameworks for Synchronous Event Handling, Connections, and Service Initialization
  • The Reactor and Acceptor-Connector Patterns
  • The ACE Reactor Framework
  • Applying the ACE Reactor to JAWS
  • The ACE Acceptor-Connector Framework and Applying it to JAWS
• Patterns and Frameworks for Service Configuration and Activiation
  • The Component Configurator Pattern
  • The ACE Service Configurator Framework
  • Applying the ACE Service Configurator to JAWS
  • Applying the Activator Pattern to JAWS
• Patterns and Frameworks for Concurrency and Synchronization
  • The Active Object Pattern
  • The ACE Task Framework
  • Applying ACE Task and Acceptor-Connector to JAWS
  • The Half-Sync/Half-Async Pattern
  • Implementing Half-Sync/Half-Async Using ACE
  • The Monitor Object Pattern
  • Applying the Monitor Object and Synchronization Patterns to JAWS
  • The Leader/Followers Pattern
  • Applying the Leader/Followers Pattern and ACE_TP_Reactor to JAWS
• Patterns and Frameworks for Asynchronous Event Handling
  • The Proactor pattern
  • The ACE Proactor Framework
  • Applying the ACE Proactor Framework to JAWS
  • The Asynchronous Completion Token Pattern and Applying it to JAWS
• Summary
  • Evaluating Patterns and Frameworks for Concurrent and Networked Software