BSB recently developed a tool which makes it possible to automatically convert applications developed in PowerBuilder into Java. The thus-converted applications enjoy all of the advantages which are intrinsic to Java: being based on an open architecture, having the ability to evolve (scalability), disposing of a large number of user interfaces (thick and thin clients) and being perennial. Furthermore, these applications have a behaviour and a look & feel which are virtually identical to the PowerBuilder application, making it unnecessary to train users on how to deal with a new application.
Why convert applications into Java ?
Several reasons impel companies to convert their business applications into Java :
Â· Firstly, many of them wish to sharply limit the number of development languages used internally in order (among other things) to reduce the time devoted to maintaining heterogeneous or proprietary systems and to significantly simplify the upgrading of applications. Java, which today has become a de facto standard, is one of the languages frequently chosen by such companies.
Â· In addition, companies which work with PowerBuilder applications are often confronted with the necessity of evolving from a Client/Server model towards an n-tier environment (including presentation tier, business tier and database tier), an environment which is offered by Java. The Client/Server model no longer corresponds to strategic visions of the IT of the future, in which Internet integration is one of the key factors. Use of the web interface has become generalised and thin client interfaces are essential to respond to demands for mobility, remote access, real time, etc.
Â· Moreover, Java applications still offer an exceptional openness with regard to the environments in which they run. As a result, companies which have developed their applications in Java enjoy very great independence towards the hardware suppliers.
How is the PowerBuilder application converted into Java ?
BSB developed a converter which automatically translates all of the business components of a PowerBuilder application into Java objects. This automatic translation is performed by means of a parser/compiler. Given that PowerBuilder is a proprietary language and the code is not published, a syntactic grammar of the PowerBuilder language had to be created. This grammar, as well as the translation rules, are used by the parser during the automatic translation. The parser first regroups the characters in order to recompose the words of the language, then regroups the words and recomposes the sentences in order to obtain the ASTs (Abstract Syntax Trees). These ASTs are then used to generate the dictionary of data and translate the code.