Big Data Integration

Module Information

Module Objectives

• How to implement a cloud based storage solution for a company's big data needs
• The knowledge needed to integrate desktop and web applications to utilize web services and stored data.
• How cloud based DNS solutions can help to optimize a company's IT infrastructure
• How cloud based servers and service implementations can be easily deployed for rapid utilisation
• The steps involved in data exchange between web services and cloud based applications

Resources - References

• Programming Amazon EC2, Juirg van Vliet 1st 2011 O’Reilly
• Google Compute Engine, Marc Cohen 1st 2011 O’Reilly
• Python for Google App Engine, Massimiliano Pippi 1st 2015 Packet
• Big Data Fundamentals Concepts, Drivers & Techniques, Thomas Erl, Wajid Khattak, and Paul Buhler, Prentice Hall

Service-Oriented Architecture (SOA)

• A service-oriented architecture (SOA) is a style of software design where services are provided to the other components by application components, through a communication protocol over a network.

• A service is a discrete unit of functionality that can be accessed remotely and acted upon and updated independently, such as retrieving a credit card statement online.

• SOA provides access to reusable Web services over a TCP/IP network,

Web service

• A software component stored on one computer that can be accessed via method calls by an application (or other software component) on another computer over a network

• Web services communicate using such technologies as:
  • XML, JSON and HTTP
  • Simple Object Access Protocol (SOAP): An XML-based protocol that allows web services and clients to communicate in a platform-independent manner

Basic concepts:

• Remote machine or server: The computer on which a web service resides
• A client application that accesses a web service sends a method call over a network to the remote machine, which processes the call and returns a response over the network to the application
• Publishing (deploying) a web service: Making a web service available to receive client requests.
• Consuming a web service: Using a web service from a client application.
• In Java, a web service is implemented as a class that resides on a server.

An application that consumes a web service (client) consists needs:

• An object of a proxy class for interacting with the web service.
• The proxy object handles the details of communicating with the web service on the client's behalf

JAX-WS:

• The Java API for XML Web Services (JAX-WS) is a Java programming language API for creating web services, particularly SOAP services. JAX-WS is one of the Java XML programming APIs. It is part of the Java EE platform.
  • Requests to and responses from web services are typically transmitted via SOAP.
  • Any client capable of generating and processing SOAP messages can interact with a web service, regardless of the language in which the web service is written.

Creating - Publishing - Testing and Describing a Web Service using NetBeans

• In Netbeans, you focus on the logic of the web service and let the IDE handle the web service’s infrastructure

• Example: HugeInteger web service:
  • Provide methods that take two “huge integers” (represented as Strings)
  • Can determine their sum, their difference, which is larger, which is smaller or whether the two numbers are equal

Create a Web Service - Locally

• We first need to to do some configuration in NetBeans:
  • Go to /home/hduser/netbeans-8.2/etc/netbeans.conf:
    • Find the line: netbeans_default_options
    • If -J-Djavax.xml.accessExternalSchema=all is not between the quotes then paste it in.

• If you are deploying to the GlassFish Server you need to modify the configuration file of the GlassFish Server (domain.xml):
  • /home/hduser/glassfish-4.1.1/glassfish/domains/domain1/config/domain.xml
    • Find : <java-config
    • Check the jvm-options for the following configuration
    • <jvm-options>-Djavax.xml.accessExternalSchema=all</jvm-options>
    • It should be there by default, if not paste it in, save file and exit
    • You can now start Netbeans IDE

• Create a Web Service in NetBeans:
  • Choose File > New Project
  • Select Web Application from the Java Web category

Consuming a Web Service in Java using NetBeans IDE

Netbeans 6.5 - 9 and Java EE enable programmers to "publish (deploy)" and/or "consume (client request)" web services

This document provides step-by-step instructions to consume a web service in Java using NetBeans IDE.

In the project, we will invoke a sorting web service through its WSDL link: http://vhost3.cs.rit.edu/SortServ/Service.svc?singleWsdl

• Step 1 - Createa JavaProject:
  • We are going to name it: SortClient

• Step 2 - Generate a Web Service Client:
  • After the Java Project has been created, go to the Project Tree Structure, Right click on Project and select New and then choose Web Service Client.
  • Specify the WSDL URL as: http://vhost3.cs.rit.edu/SortServ/Service.svc?singleWsdl
  • Click Finish

• Step 3 - Invoke the Service:
  • Expand the Web Service References until you see the operation lists. Drag the operation you want to invoke to the source code window, such as "GetKey". A piece of code is automatically generated to invoke that operation.
  • Drag MergeSort to the source code window and the corresponding code is automatically generated,too.
  • In the main function, add the code to call the two functions: getKey() and mergeSort();As it is a call to a remote service, RemoteException needs to be listed in the throws cause