Creating Web services from legacy host programs

An important prerequisite to connecting existing systems to the Web is the ability to link client programs on the Web site with server programs on the host. The host programs have not been conceived to run in an internet mode. They are either online transactions or batch steps. This paper describes a tool supported process to cut out selected sections of legacy code and to provide them with an XML interface. The same interface is used to generate a Java class, which creates XML messages returning from the server. This class is then built in to the package managing the Web site. In this way a consistent communication between the Web site and the server components on the host is ensured.