On Thu, 2012-02-16 at 07:46 -0600, xyz32 wrote: > Wow, this is... Confusing. > There is no windows/linux version of a java application. Just JVM is > aware of the OS, the application is not. > That's true for pute Java apps, but there are applications out there that depend on JNI, which allows native code to be included as part of it. These are seldom, if ever, portable between operating systems. > In fedora you have the "alternatives" tool. > ... and most other Linuxes and many Unices too, probably, but I don't think its relevant here. Its use is to allow a seamless switch between functionally identical Linux/UNIX services, such as the sendmail and Postfix mail servers (MTAs). To be useful the services must have identical interfaces for both programs and users. For instance, all MTAs communicate for the SMTP protocol and, because sendmail (the archetype of MTAs), provides the 'sendmail' command line utility which can be used by programs as well as people to send mail messages, every alternative to the sendmail MTA has to provide such a program and it must have identical functionality to the Sendmail sendmail or using an alternative such as Postfix or Qmail would break the system. You'll notice that 'alternatives', correctly, doesn't deal with databases. This is because they all have their own SQL dialect and these are mutually incompatible to a greater or lesser extent, with Oracle and MySQL being the most deviant dialects. There is a set of Java alternatives, but this seems to be restricted to OpenJava and gcj. Oracle/Sun Java, which I use, is not an available alternative. Fortunately I can easily tune OpenJava out by adjusting its place in the PATH list, so alternatives becomes irrelevant for this switch. Martin
