This project is concerned with providing easy access from Java applications to information stored in relational databases. This project addresses two main issues in this regard, firstly the provision of a higher level connection mechanism and secondly support for object persistence of Java objects via a relational database.
The vendors of different databases have traditionally implemented their databases in a way which is often different to those developed by other database vendors. As a result organisations with heterogeneous databases found they had to develop a separate application for each database. This was further complicated by the fact that the various databases could be implemented in different programming languages, operate on different platforms and use different networking protocols. There have been many different efforts aimed at solving the problem of database connectivity by providing a standard for database access, but it has remained elusive. The World Wide Web (Web) and its enabling technologies are based on open standards and the Java language is platform independent, together they can address the issues of database independence and offer a potential solution.
This project aims to develop a system which will simplify the problems of database connectivity. The system will be developed using Java and will provide persistence via object-relational mapping. A relational database connected to the Java program will provide support for storage of object attributes and facilitate persistence.
The project is made up of five sections as outlined below;
· Chapter Two provides an overview of the problems facing organisations as they attempt to develop applications which can satisfy all of their information needs. It then outlines the architectures used by database applications and the advantages and disadvantages of each. Various Web technologies are also considered in this context.
· Chapter Three addresses the problem of database independence and describes in detail the solution provided by Java and JDBC. The different scenarios in which JDBC can be used are outlined along with their implications for the application.
· Chapter Four introduces the Object Modelling Technique (OMT) (Rumbaugh et al., 1991), a popular object-oriented systems development methodology. The general principles of this methodology are applied to design the database connection and mapping frameworks. This design is further refined using the Jackson Structured Programming (JSP) (Culwin, 1998) schematics to address inner class design.
· Chapter Five is concerned with the implementation. It first discusses the implementation features of JDBC which were incorporated into the design and then considers the translation from design into working Java code. The database system is tested by developing an application that utilises the Connection and Mapping frameworks.
· Chapter Six describes evaluation and outlines the methods employed to gauge the success of the system. The evaluation leads to recommendations for future enhancements.