+
+#
+# error handling. REQUIRED: if this script fails, it must give non-zero exit value
+#
+# We exit non-zero with an explanation echod to standard
+# out in some situations, like bad input or failed keygen.
+# We exit non-zero without explanation in other situations
+# like command not found, or file access perms error.
+#
+# exit without explaining to stdout if some error
+set -e
+
+[ -z "$JAVA_HOME" ] && { echo FAILURE: JAVA_HOME is not set; exit 1;}
+JAVA=${JAVA_HOME}/bin/java
+
+[ -e ${JAVA_HOME} ] || { echo FAILURE: java home does not exist: ${JAVA_HOME}; exit 1;}
+[ -e ${JAVA} ] || { echo FAILURE: java executable does not exist: ${JAVA}; exit 1;}
+