protected void buildExpression()

in log4j-core/src/main/java/org/apache/logging/log4j/core/util/CronExpression.java [416:500]
69 lines of code
30 McCabe index (conditional complexity)

    protected void buildExpression(final String expression) throws ParseException {
        expressionParsed = true;

        try {

            if (seconds == null) {
                seconds = new TreeSet<>();
            }
            if (minutes == null) {
                minutes = new TreeSet<>();
            }
            if (hours == null) {
                hours = new TreeSet<>();
            }
            if (daysOfMonth == null) {
                daysOfMonth = new TreeSet<>();
            }
            if (months == null) {
                months = new TreeSet<>();
            }
            if (daysOfWeek == null) {
                daysOfWeek = new TreeSet<>();
            }
            if (years == null) {
                years = new TreeSet<>();
            }

            int exprOn = SECOND;

            final StringTokenizer exprsTok = new StringTokenizer(expression, " \t",
                    false);

            while (exprsTok.hasMoreTokens() && exprOn <= YEAR) {
                final String expr = exprsTok.nextToken().trim();

                // throw an exception if L is used with other days of the month
                if (exprOn == DAY_OF_MONTH && expr.indexOf('L') != -1 && expr.length() > 1 && expr.contains(",")) {
                    throw new ParseException("Support for specifying 'L' and 'LW' with other days of the month is not implemented", -1);
                }
                // throw an exception if L is used with other days of the week
                if (exprOn == DAY_OF_WEEK && expr.indexOf('L') != -1 && expr.length() > 1 && expr.contains(",")) {
                    throw new ParseException("Support for specifying 'L' with other days of the week is not implemented", -1);
                }
                if (exprOn == DAY_OF_WEEK && expr.indexOf('#') != -1 && expr.indexOf('#', expr.indexOf('#') + 1) != -1) {
                    throw new ParseException("Support for specifying multiple \"nth\" days is not implemented.", -1);
                }

                final StringTokenizer vTok = new StringTokenizer(expr, ",");
                while (vTok.hasMoreTokens()) {
                    final String v = vTok.nextToken();
                    storeExpressionVals(0, v, exprOn);
                }

                exprOn++;
            }

            if (exprOn <= DAY_OF_WEEK) {
                throw new ParseException("Unexpected end of expression.",
                        expression.length());
            }

            if (exprOn <= YEAR) {
                storeExpressionVals(0, "*", YEAR);
            }

            final TreeSet<Integer> dow = getSet(DAY_OF_WEEK);
            final TreeSet<Integer> dom = getSet(DAY_OF_MONTH);

            // Copying the logic from the UnsupportedOperationException below
            final boolean dayOfMSpec = !dom.contains(NO_SPEC);
            final boolean dayOfWSpec = !dow.contains(NO_SPEC);

            if (!dayOfMSpec || dayOfWSpec) {
                if (!dayOfWSpec || dayOfMSpec) {
                    throw new ParseException(
                            "Support for specifying both a day-of-week AND a day-of-month parameter is not implemented.", 0);
                }
            }
        } catch (final ParseException pe) {
            throw pe;
        } catch (final Exception e) {
            throw new ParseException("Illegal cron expression format ("
                    + e.toString() + ")", 0);
        }
    }