Why does JDK install two JREs?
I've never really understood it, and since I've installed Java SE 6.0 Update 4 about five times in the last few days, it's really started to become irksome. When you install a JDK on Windows, it installs one JRE under the JDK directory (e.g. %JAVA_HOME%/jre) and then, having finished installing the JDK runs out and installs another JRE in a different directory.
Why? What's the point behind this? I realize it allows you to uninstall the JDK and leave the JRE intact, but isn't that like having Microsoft install Office as a suite, and then Word, Excel, etc into different directories so that you can uninstall Office without uninstalling Word, Excel and Powerpoint?
It's weird, and silly. Is there a rationale that I'm missing?
Labels:
installation,
java,
oddity,
software
4 comments:
The JDK VM includes more debug information than does the JRE VM.
Try throwing an exception under each and examine the difference in the stack traces.
Did a simple test, no difference - could you be more specific?
And if that were true, why bother installing the 'consumer' JRE?
Ah, yes, the line numbers are available in the stack trace in a slightly more complicated example - the JRE classfiles contain the debug information. Well, that at least explains that there's a difference, although i'm still not sure why I'd want both JREs.
There's probably an impact on performance.
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