JACOB

Most programs written before the 1980s, applications were written in procedural languages, such as Pascal and C, for instance, and this is why the code could not be reused for additional tasks. The new programming languages, like C++ and Java, have facilitated code re-utilization.

However, even now languages as C++ still provide little for reusing binary objects. Making the code reusable entails finding a way to employ them as COM components that rely on Java-based components. As you probably guessed, this means that the latter need to have a compatible version of the Microsoft Java Virtual machine installed and, adjacently, more memory.

The good news is that nowadays, you can create Java COM components with dual interfaces, custom and automation interfaces. On the other hand, the method for calling these objects within Java applications can sometimes be tricky and time-consuming, to be worth the trouble.

JACOB is a lightweight tool that enables programmers to call COM automation components from Java. The program uses JNI to make native calls to the COM libraries and enable you to work in a general-purpose programming language that is platform independent. If you are looking for a tool to help you integrate enterprise systems with legacy applications, then perhaps the tool can come in handy.