A simple SOAP based web service has been developed that uses a android platform as an user interface from which a user access a database residing in the other server. the web service exposes web methods over the internet so that any other application can use those methods for own requirements.

1. Md Ashraful Haque

2. Introduction
 In present days, the ability to seamlessly exchange information between internal
business units, customers, and partners is vital for success
 Yet most organizations employ a variety of disparate applications that store and
exchange data in dissimilar ways and therefore cannot "talk" to one another
productively
 Web services have evolved as a practical, cost-effective solution for uniting
information distributed between critical applications over operating system, and
language barriers that were previously impossible
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3.  In last few years the use of smartphones and tablets has been increased
enormously, changing the scenario of mobile phone usage
 The applications associated with this smartphones and tablets are the most
attractive tools which provides a touch and click interface to the users
 According to Nielsen Media Research
• In 2014, the mobile users spent 89% of their time on media through the mobile
Application
Contd… 3

4.  Now-a-days Android operating system has become a predominant platform in the
market of application development. (Shanmugapriya et al., 2011)
 Several companies as part of OHA (Open Handset Alliances) developing millions
of Android applications
 e-learning to m-learning, e-commerce to m-commerce
 In this shifting from web-based application to mobile application, web services
act as the intermediate interface
Contd… 4

5. Web service overview
 Web service is a standardized technology that
• Exposes information, functionalities and business logic of a existing web-
server/web page application over the Internet
• Allows other system/application to access these information, functionalities
and business logic by calling the web methods
• provides program-to-program interface between the systems/application
• Uses some open standards or protocols like SOAP, WSDL and UDDI
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6. o Device A request some data from
other system B over the network
o System B exposes the data using a
web service through the network
o System A gets the response data as
a result
 Web services communicate between different systems/applications
Contd…
WEB SERVICE
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7.  Web services are independent of programming language and platform (Kao,
2001)
Contd… 7

8. Architecture of web services
 Web services Architecture is defined by SOA (Service Oriented
Architecture)
• SOA concept refers to a architecture based on some distinct services
• Interaction between these services exist
 According to SOA there are three components in a web services-
• Service roles/actors
• Service operations
• Standards/Protocols
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9. SERVICE
REQUESTOR
SERVICE PROVIDER
SERVICE
REGISTRY
XML
XML
SERVICE RESPONSE
SERVICE REQUEST
BIND/INTERACT
PUBLISH
(WSDL)
FIND/LOCATE
(WSDL+UDDI)
SOAP
SOAP
 The service actor are-
o Service provider
o Service Requestor
o Service Registry
 The operations performed
o Publish
o Find/Locate
o Bind/Interact
Contd… 9

10.  Standards/protocols of web service
 SOAP (Simple Object Access Protocol)
• It is XML-based messaging protocol, where XML (eXtensible Markup Language)
provides tags to each element of the message
• The basic communication between the systems are served by SOAP Request and SOAP
Response
• Also known as Communication Protocol
Contd… 10

11. Contd…
• Framework of SOAP-
o Has components like
envelop, header, body
o The message elements are
encapsulated in the SOAP
envelop
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12. Contd…
 WSDL(Web Services Description Language)-
• The service description is specified in the WSDL file
• XML-document format
• Provides location (URL) of the service and description of the service to a client
application
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13. Contd…
 UDDI (Universal Description, Discovery and Integration)
• XML-based standard for publishing, finding and registering web services
• It acts as a centralised registry that enables the clients to locate the web services.
• Closely resembles online “Phone Directory” (Dustdar, et al., 2005)
• Provide two basic information
o Service description along with the way to encode it
o Query and update APIs of the registry
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14. Introducing the Android Application
 Android Platform
• Open source software stack for mobile application development
• Google initiated android project with Open Handset Alliance including 30 companies
(Knutsen, 2009)
• Linux based kernel and runs its application on Dalvik Virtual Machine
• Several version has released till today, the latest version released is Lollipop
(Android 5.0) and Android M is the upcoming release.
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15. Contd…
 Advantages of Android Platform
• Open source software
• Android integration in any device
• Devices can be easily customizable
• No external review required
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16. Contd…
 Architecture of android platform
o Four layers and five sections
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17. Importance of web services in android
Applications
 Using and implementing functionalities of existing web-based systems/applications
 Access data from remote database server easily
 Client users can access the web service in an emergency situation if health related web
services are available
 User get information on touch and click using a web service through the application
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18. Developing a web service in java
Programming language
 Creating a web service that will access a remote database server
 Creating a web service class and web methods
 Creating Database Source Name (DSN)
 Accessing database in java
 Deploy and Testing the web service
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19. Contd…
 Creating web service class and web methods
• A web service consists of a set of web service class and web methods
• Web service classes encapsulate all the web methods used in the service
• Web methods are the actual implementation of exposing the functionality of a
system over the network
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20. Contd..
o @WebService (serviceName = “test”)
o @WebMethod(operationName=“loginid”
)
o @WebParam (name =“username”)
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21. Contd…
 Creating Database Source Name (DSN)
• Database source name provides connectivity to a database through an
ODBC driver
• DSN contains database name, database
driver, directory and other information
• Once a DSN is created, one can use the
DSN in an web service to invoke
information from the database
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22. Contd…
 Accessing the database in Java
• Java provides a set of classes that connects the database by loading the ODBC
driver
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23. Contd…
 Deploying and Testing web service
• To make the web service available to any client application, the service have to be
deployed
• The web service has been deployed to the Glassfish server so that the service can
be available over the Internet
• The web service can be tested by tester in the browser
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24. Contd…
Web method is
tested by click
on the loginid
button
Service
description file
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25. Contd…
 The WSDL file
o URL to access the web
service
o Method or the operation
o Data types used in method
parameter and return types
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26. Contd…
Parameter Provided
Method returns a value
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27. Contd…
o The SOAP request and
SOAP response.
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28. Consuming the web service in Android
applications
 An android application can be developed as client application for consuming the
web service
Android application creates a
request to the web service,
the web service responses to
the application with desired
result
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29. Contd…
 Key points of Android Application for consuming a web service are-
 Creating layout files in XML
 Creating activity class files in JAVA
 Accessing the web service inside the application
 Internet Permission in the manifest file
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30. Contd...
 Creating Layout file in XML-
• Framework of each activity of an application is defined in the layout file
• Just a XML file with tags
• It can define different elements such as
o Form widgets- Buttons, Progress Bar, TextView etc
o Text fields- EditText, Password, Date, E-mail etc
o Layout- Linear, Relative etc
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31. Contd…
Referring a linear
layout
Referring a textview
within the
application
Referring a text editor
in the application
Referring a button
to be clicked
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32. Contd…
 Creating the activity class file in java
• most important files in the application written in java programming language
• ultimately converted in Dalvik executable file and runs the application
• Inherits the base classes of android like Activity Class, ActionBarActivity Class etc
• Implements and overrides the necessary methods such as onCreate(), onClick() etc
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33. Contd…
• performing the following functionality-
o Defines the XML-layout elements and provide reference of the XML elements
into java
o sets the content view of the application as per the XML-layout file
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34. Contd…
o Sets tasks in application after the button is clicked
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35. Contd…
 Accessing the web service inside the application
• Most important part of the application that actually calls the web method
• Add a third party library KSOAP2 (http://ksoap2.sourceforge.net) to the library
of Android project that is optimized for Android
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36. Contd…
• Firstly defines the namespace of the web service, name of the web method, SOAP-
Action and the URL of the web service description
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37. Contd…
• SOAP request is fired based upon the specified web method of the web service
and properties are added as per the requirement
• SOAP envelop is created and version of the SOAP is declared
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38. Contd…
• Passing the request to the envelop
• Connecting to the web service using the URL and invoking the web method with
request
• The response of the request is stored as String
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39. Contd…
 Internet permission in the manifest file
• the application needs a permission for accessing the Internet
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40. Current Technology
 RESTful-based web service
• has gained wide acceptance across worldwide in last few years
• It is being used as a simpler alternative to SOAP and WSDL-based web services
(Zur et. al, 2005)
• REST stands for Representational State Transfer, defines a set of architectural
principles for developing web services
• It typically communicate over HTTP with the same HTTP principle CRUD
(create, Read, update, Delete)
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41. Conclusions-
 Companies/organisations are developing web services to integrate the existing
functionalities and resources of multiple systems/applications
 e-commerce companies like Flikart, Amazon, Snapdeal, Myntra, Paytm expanding
themselves through mobile application version
 Web services can be developed for the agricultural information system so that any
client application can access those facilities easily
 Further studies on RESTful web services for Android application can be done
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