Web Service Technologies- WSDL

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Table of Contents

INTRODUCTION3

PROBLEM STATEMENT4

PURPOSE/OBJECTIVES4

RESEARCH QUESTIONS5

THESIS CONTRIBUTION5

SCOPE OF THE THESIS6

LITERATURE REVIEW6

RESEARCH METHODOLOGY9

REFERENCES18

Web Services Technologies- WSDL

Introduction

Many companies provide access to their services and products through web services. For example, a wide variety of businesses that provide services to other businesses, such as shipping companies and credit card processing organizations, provide a web service for accessing those services. Further, some businesses that target consumers, such as Amazon or eBay, also provide access to their products or services via web services(Csallner , 2010: 1025-1050). By doing so, these companies allow outside parties to utilize or resell their services or products. According to the companies that provide these services, web services are a significant part of their business. For example, eBay claims that third-party applications account for over 25% of their listings and Amazon claims that over 200?000 developers, start-ups, and Fortune 1000 companies use their technologies (Elbaum, 2010: 46-56).

Typically, Web Service Definition Language (WSDL) files are used to provide a partial specification of the interface to a web service. These specifications focus on the data types of parameters and returned values of the application. Developers of clients to the web services are expected to use the information in the WSDL and in informal documentation to build applications that make use of the web services (Xie, 2009: 345-371). However, the WSDL files and informal documentation often contain errors or are imprecise. For example, an early version of what became Amazon's Advertising API used strings for every element, including those such as quantities or prices that could be more precisely specified as numeric types. Additionally, recent versions of eBay's Trading Web Service include a number of elements where the informal documentation and the WSDL file disagree on whether they are required or not, indicating that one of these sources of information is incorrect.

Problem Statement

In order to develop robust and reliable clients for web services, users of these services need accurate information about the expected inputs. However, the client developers do not have access to the underlying implementation of the web service, hence identifying problems in the WSDL or documentation can be difficult(Artzi, 2011: 45-61). Therefore, an existing analysis of web application interfaces has been extended to find anomalies in the WSDL files describing web services(Pacheco, 2009: 504-527).

Prior work presented the WebAppSleuth methodology for characterizing specialized search engines, web applications with a single HTML form and corresponding form handler that allow users to perform web-based queries on structured data. This earlier version of WebAppSleuth performed an automated analysis that began by examining the interface described by the HTML search form. It semi-automatically constructed and submitted inputs to the form handler, and analyzed the responses to infer properties that describe the relationships between input variables and values and the corresponding responses (Bartolini , 2009: 326-33). These inferred properties were then examined to identify problems in the analyzed web application. WebAppSleuth was applied to six production search engines and found anomalous behavior on five of these applications.

Purpose/Objectives

Web Service Definition Language (WSDL) is being increasingly ...