Migrating From C# To Java For Large Financing System

With the development of the third industrial revolution, information technology has achieved explosive progresses since the mid-twentieth. With the development of financial information systems, the problems caused by legacy systems have been highlighted. These legacy systems always have been developed and run for many years. Some of the techniques used previously may have been outdated which will cause the maintenance of the systems be difficult, costly and low efficiency. And the running environment of the systems may also be changed during the years. There may be better choices or even the environment may be abandoned by the original vendor. All these changes prompted the birth of the software migration.However, for a large financial system, which contains often thousands or even millions lines of code, direct code level migration in a manual, line-by-line way will absolutely mean huge manpower cost. Manual code migration becomes particularly unrealistic when much discordance exists between the two involved programming languages, e.g. Java and C#. In this sense, it is necessary to put forward a unified scheme of mass code transformation that works systematically and automatically for the most common technical cases. Only in this way can the code migration of a large financial system be carried out smoothly.This paper researched and implemented the migration from C# to Java for a large financial system based on the A system of B company.The first chapter briefly describes the research background and significance, as well as the whole content of the paper.The second chapter discussed the basic definition of the software migration, the metrics of software migration, and the procedures of software migration and at last it summarized the current situations and problems of software migration.The third chapter discussed the syntax differences from C# and Java. And it compared several tools for the language migration, analyzed their strengths and weaknesses, to choose the most suitable one to migrate the pure logic code. The fourth chapter analyzed the ways of parsing XML in both C# and Java, finding their differences and corresponding rules. Then we evaluated dom4j and jdk implementations, finding dom4j is most suitable for the migrating of XML related code in A system.The fifth chapter introduced the migration of database entity classes. It introduced the theory of the code generation tool for database entity classes. Then it introduced the migration proposal for the code templates based on the tool.The sixth chapter researched in C# WCF and Java web service technology, comparing their advantages and disadvantages, and finally chose the most suitable proposal to implement the migration of communication part of A system.The seventh chapter summarized the whole paper and prospected for future research directions.