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Portability Considerations
Java is of course known as the “write once, run anywhere language.” In reality, we do need to have an awareness of how the various components we want to use will interact with the operating system, the Java Virtual Machine (JVM), the hardware we plan to use, and with any other components that we will select. For example, it would not be good to select a component that requires a version 1.2 or later JVM if the only JVM supported on the hardware platform you are developing for is version 1.1. Although this seems obvious, you might be amazed at how many projects that have failed because the developers developed an application on one platform for deployment on another platform that only supported an earlier version of the JVM.
The issue of compatibility is exacerbated by the widespread use of heterogeneous computing environments. In many environments (universities, for example), the machines may be running operating systems such as Windows
98, which have different capabilities than more advanced operating systems such as Linux or Windows XP. Any or all of these systems may be present within the institution. If supporting all of these machines and operating systems is important for your purposes (for J2EE training, for example), then it is important to note any operating system or hardware issues with the component. In heterogeneous environments such as these, you’ll have to make a choice between programming for the lowest common denominator (say JVM 1.1) and having multiple versions of your software available for different clients.
