Model Query Language And Realization Of UML Class Diagram Based On Sketch Input

With the rapid development of software engineering, the software scale is growing fast. The uncontrollable of software scale result in the increase of software complexity. Meanwhile, models are becoming increasingly important in the software development process since the rise of model-driven engineering. As a consequence, an increasingly large number of models are being produced and used by software engineers. It is much more difficult for software maintenance, understand and reuse. The quality of software can not be fully guaranteed. So, how to find usefull models(codes) in such a large-scale model(code) repository has become a hot issue. Model query can provide good technical support for solving above problems.Currently, most of the model query technologies are based on textual query lan-guages. However, textual query languages are not easy to be understood and used, which impede the development of model query. In this paper, we propose an UML class diagram model query language which is based on sketch input. The parsing en-gine and query engine are also presented. First, specifying users’query intention in terms of the syntax of visual query language. Then, getting query conditions from the parsing engine and obtaining query results through the query engine. This paper aims to provide an entire UML model query method. The main contributes of this paper are:1. UML class diagram model query language based on sketch inputThis paper proposes an UML model query language based on sketch input which is a visual query language, since most of the textual query languages have some disadvantages. We define the language’s syntax and semantics combined with the meta-model of UML and the formal language OCL. Graphical Elements in the language customize and extend the notations of UML class diagram, which are bind with simple syntax and easy to be used. Because of its graphical definition, it is intuitive, readily understood and can reduce errors while specifying model query.2. Parsing engine for the visual model query languageThe model query language that is based on sketch input in this paper specifies model query intention in a graphical way. However, the query engine can not recognize inputs with graphical format. So, a parsing engine is necessary. Users should specify the query intention according to the language’s syntax through support touch-based devices. Then, getting query conditions through the parsing engine and stored in XML which is a intermediate storage format and the input of query engine.3. Query engine with optimized algorithmThe query method in this paper is based on a visual model query language, which needs a query engine to execute query. The query algorithm in this paper is based on structure pattern matching. Before query, we make reduction to the model repository twice in order to narrow the scope of query and improve the query efficiency. First, we extract the main information of model elements and remove data irrelevant to query. Then, building type index, cutting the whole model file into pieces of files according to different types. In addition, we generate a priority sequence for the target model elements in view of features of UML model. The priority sequence can speed up the model elements’ filtering and improve the query efficiency.