[ASF BZ 61441] Wrong JAVA_HOME/JRE_HOME auto-detection on RHEL

+++ This bug was initially created as a clone of Bug #1120255 +++
Description of problem:
On RHEL, when java is installed from rpm, the JAVA_HOME or JRE_HOME environment variables are not set. Luckily, the tomcat startup scripts are able to auto-detect them by:

daemon.sh:96:

JAVA_BIN="`which java 2>/dev/null || type java 2>&1`"
test -x "$JAVA_BIN" && JAVA_HOME="`dirname $JAVA_BIN`"
test ".$JAVA_HOME" != . && JAVA_HOME=`cd "$JAVA_HOME/.." >/dev/null; pwd`

setclasspath.sh:35:

JAVA_PATH=`which java 2>/dev/null`
if [ "x$JAVA_PATH" != "x" ]; then
  JAVA_PATH=`dirname $JAVA_PATH 2>/dev/null`
  JRE_HOME=`dirname $JAVA_PATH 2>/dev/null`
fi

The problem is that when java is installed from rpm, `which java` evaluates to '/usr/bin/java', which is a symlink maintained by alternatives. The code snippets above will evaluate to JAVA_HOME and JRE_HOME being set to '/usr'.

Having JRE_HOME set to '/usr' doesn't seem to cause problems for tomcat, because I verified that this issues has been present at least since EWS-2.0.1 and there haven't been any issues with tomcat suggesting a bug with JAVA_HOME/JRE_HOME.

The problem manifests itself when running the daemon.sh script:

# ./daemon.sh start'
Cannot find any VM in Java Home /usr

# grep 'Cannot find any VM in Java Home' ./*
Binary file ./jsvc matches

jsvc is only used in daemon.sh, therefore this problem was not seen when starting tomcat using startup.sh or catalina.sh.

I think a good fallback for JAVA_HOME and JRE_HOME is '/usr/lib/jvm/java' and '/usr/lib/jvm/jre' respectively.

Version-Release number of selected component (if applicable):
JWS 3.1.0 GA

How reproducible:
100%

Steps to Reproduce:
1. cd tomcat7/bin
2. ./daemon.sh start

Actual results:
Cannot find any VM in Java Home /usr