improve JAVA_HOME detection, refs OF-589

git-svn-id: http://svn.igniterealtime.org/svn/repos/openfire/trunk@13355 b35dd754-fafc-0310-a699-88a17e54d16e

src/bin/openfire.sh

@@ -20,13 +20,16 @@ case "`uname`" in
            fi
            ;;
   Linux*) linux=true
-          jdks=`ls -r1d /usr/java/j*`
-          for jdk in $jdks; do
-            if [ -f "$jdk/bin/java" ]; then
-              JAVA_HOME="$jdk"
-              break
-            fi
-          done
+          if [ -z "$JAVA_HOME" ]; then
+              shopt -s nullglob
+              jdks=`ls -r1d /usr/java/j* /usr/lib/jvm/* 2>/dev/null`
+              for jdk in $jdks; do
+                if [ -f "$jdk/bin/java" ]; then
+                  JAVA_HOME="$jdk"
+                  break
+                fi
+              done
+          fi
           ;;
 esac