more explicit check of Java executable -- relevant for Linux x86/x86_64 mismatch and absence on Mac OS Lion;
#!/usr/bin/env bash
#
# Author: Makarius
#
# DESCRIPTION: invoke Java within the Isabelle environment
CLASSPATH="$(jvmpath "$CLASSPATH")"
JAVA_EXE="${THIS_JAVA:-$ISABELLE_JAVA}"
if "$JAVA_EXE" -version >/dev/null 2>/dev/null; then
:
else
echo "Bad Java executable: \"$JAVA_EXE\"" >&2
exit 2
fi
if "$JAVA_EXE" -server >/dev/null 2>/dev/null; then
SERVER="-server"
else
SERVER=""
fi
exec "$JAVA_EXE" -Dfile.encoding=UTF-8 $SERVER \
"-Djava.ext.dirs=$("$ISABELLE_HOME/lib/scripts/java_ext_dirs")" "$@"