XML files are frequently used by developers when building Web applications or Java EE applications. However, maintaining XML files is challenging and time-consuming because the correct usage of XML entities is always domain-specific and rarely well documented. Also, the existing compilers and program analysis tools seldom examine XML files. In this thesis, we developed a novel approach to XML file debugging called Xeditor where we extract XML consistency rules from open-source projects and use these rules to detect XML bugs. There are two phases in Xeditor: rule inference and application. To infer rules, Xeditor mines XML-based deployment descriptors in open-source projects, extracting XML entity pairs that frequently co-exist in the same files and refer to the same string literals. Xeditor then applies association rule mining to the extracted pairs. For rule application, given a program commit, Xeditor checks whether any updated XML file violates the inferred rules; if so, Xeditor reports the violation and suggests an edit for correction?. Our evaluation shows that Xeditor inferred rules with high precision (83%). For injected XML bugs, Xeditor detected rule violations and suggested changes with 74.6% precision, 50% recall. More importantly, Xeditor identified 31 really erroneous XML updates in version history, 17 of which updates were fixed by developers in later program commits. This observation implies that by using Xeditor, developers would have avoided introducing errors when writing XML files. Finally, we compared Xeditor with a baseline approach that suggests changes based on frequently co-changed entities, and found Xeditor to outperform the baseline for both rule inference and rule application. / XML files are frequently used in Java programming and when building Web application implementation. However, it is a challenge to maintain XML files since these files should follow various domain-specific rules and the existing program analysis tools seldom check XML files. In this thesis, we introduce a new approach to XML file debugging called Xeditor that extracts XML consistency rules from open-source projects and uses these rules to detect XML bugs. To extract the rules, Xeditor first looks at working XML files and finds all the pairs of entities A and B, which entities coexist in one file and have the same value on at least one occasion. Then Xeditor will check when A occurs, what is the probability that B also occurs. If the probability is high enough, Xeditor infers a rule that A is associated with B. To apply the rule, Xeditor checks XML files with errors. If a file violates the rules that were previously inferred, Xeditor will report the violation and suggest a change. Our evaluation shows that Xeditor inferred the correct rules with high precision 83%. More importantly, Xeditor identified issues in previous versions of XML files, and many of those issues were fixed by developers in later versions. Therefore, Xeditor is able to help find and fix errors when developers write their XML files.

<p>Software evolution is a crucial activity for software organizations. A specifc type of software evolution is the integration of previously isolated systems. The need for integration is often a consequence of different organizational changes, including merging of previously separate organizations. One goal of software integration is to increase the value to users of several systems by combining their functionality, another is to reduce functionality overlap. If the systems are completely owned and controlled in-house, there is an additional advantage in rationalizing the use of internal resources by decreasing the amount of software with essentially the same purpose. Despite in-house integration being common, this topic has received little attention from researchers. This thesis contributes to an increasing understanding of the problems associated with in-house integration and provides guidelines to the more efficient utilization of the existing systems and the personnel.</p><p>In the thesis, we combine two perspectives: software architecture and processes. The perspective of software architecture is used to show how compatibility analysis and development of integration alternatives can be performed rapidly at a high level of abstraction. The software process perspective has led to the identification of important characteristics and practices of the integration process. The guidelines provided in the thesis will help those performing future in-house integration to make well-founded decisions timely and efficiently.</p><p>The contributions are based on several integration projects in industry, which have been studied systematically in order to collect, evaluate and generalize their experiences.</p>

Software evolution is a crucial activity for software organizations. A specifc type of software evolution is the integration of previously isolated systems. The need for integration is often a consequence of different organizational changes, including merging of previously separate organizations. One goal of software integration is to increase the value to users of several systems by combining their functionality, another is to reduce functionality overlap. If the systems are completely owned and controlled in-house, there is an additional advantage in rationalizing the use of internal resources by decreasing the amount of software with essentially the same purpose. Despite in-house integration being common, this topic has received little attention from researchers. This thesis contributes to an increasing understanding of the problems associated with in-house integration and provides guidelines to the more efficient utilization of the existing systems and the personnel. In the thesis, we combine two perspectives: software architecture and processes. The perspective of software architecture is used to show how compatibility analysis and development of integration alternatives can be performed rapidly at a high level of abstraction. The software process perspective has led to the identification of important characteristics and practices of the integration process. The guidelines provided in the thesis will help those performing future in-house integration to make well-founded decisions timely and efficiently. The contributions are based on several integration projects in industry, which have been studied systematically in order to collect, evaluate and generalize their experiences.