On Tue, 29 Jul 2014 12:12:46 +0200, Jörg Schaible wrote:
Gilles wrote:
[...]
== Java classloader ==
The Java runtime system only allows a single instance of a class to
exist in a given classloader.
Classes are uniquely identified using the package name and class
name.
For example, the class {{{Utils}}} in the package
{{{org.apache.commons.example}}} can only appear once in a
classloader.
The classloader uses the classpath to find the classes needed by an
application.
If the classpath contains more than one jar which contains the
above
Utils class, then the JVM will load only one of the instances.
If the class instances in the different jars are identical, then
this
is not a problem, but if there are two different versions of the
class, the classloader may choose the wrong one. And different JVMs
may process the classpath in a different order.
Is that correct?
Excerpt from
http://docs.oracle.com/javase/8/docs/technotes/tools/unix/classpath.html:
-----
The order in which you specify multiple class path entries is
important.
The Java interpreter will look for classes in the directories in the
order they appear in the class path variable.
-----
Gilles
[...]
If your jars are in the WEB-INF/lib folder of a web application ...
do you
know in which sequence the application server adds those jars to the
classpath ??
I don't understand. How will the answer to that question decide of the
correctness of the sentence "[...] different JVMs may process the
classpath
in a different order" ?
Gilles
P.S. I don't know the answer to your question; if you know it, thanks
for
providing it.
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