htroot is a supposed to be a subfolder of appPath and not of dataPath,
as assumed in other places where htroot is loaded. This issue was not
visible when dataPath and appPath are equals.
- DefaultServlet includes already a class cache "templateMethodCache" which is emptied
on low mem status
- avoid classloader cache gets has no hits but over time holds all (used) servlet classes
In the 2 cases where servlet calls servlet the jvm classloader chain is
invoked and servlet class loaded by jvm loader (successful while requiring
htroot in system classpath). This patch uses the standard override design
for loaders to handle these cases (making in not longer crucial to have htroot
in system classpath, as this classLoader is mainly used for servlets and
looks in this case for the class in the configured path).
+ As the default classloader is parallelcapable we should register this too.
