lib/Tools/java

proper error message;

#!/usr/bin/env bash
#
# Author: Makarius
#
# DESCRIPTION: invoke Java within the Isabelle environment

CLASSPATH="$(jvmpath "$CLASSPATH")"
isabelle_jdk java -Dfile.encoding=UTF-8 -server \
  "-Djava.ext.dirs=$(jvmpath "$ISABELLE_JAVA_EXT:$ISABELLE_HOME/lib/classes/ext")" "$@"