private Predicate createPredicate()

in hawtio-log/src/main/java/io/hawt/log/log4j/Log4jLogQuery.java [109:191]
79 lines of code
19 McCabe index (conditional complexity)

    private Predicate<LogEvent> createPredicate(LogFilter filter) {
        if (filter == null) {
            return null;
        }
        final List<Predicate<LogEvent>> predicates = new ArrayList<Predicate<LogEvent>>();

        final Set<String> levels = filter.getLevelsSet();
        if (levels.size() > 0) {
            predicates.add(new Predicate<LogEvent>() {
                @Override
                public boolean matches(LogEvent event) {
                    String level = event.getLevel();
                    return level != null && levels.contains(level.toString());
                }
            });
        }
        final Long before = filter.getBeforeTimestamp();
        if (before != null) {
            final Date date = new Date(before);
            predicates.add(new Predicate<LogEvent>() {
                @Override
                public boolean matches(LogEvent event) {
                    Date time = event.getTimestamp();
                    return time != null && time.before(date);
                }
            });
        }
        final Long after = filter.getAfterTimestamp();
        if (after != null) {
            final Date date = new Date(after);
            predicates.add(new Predicate<LogEvent>() {
                @Override
                public boolean matches(LogEvent event) {
                    Date time = event.getTimestamp();
                    return time != null && time.after(date);
                }
            });
        }

        final String matchesText = filter.getMatchesText();
        if (matchesText != null && matchesText.length() > 0) {
            predicates.add(new Predicate<LogEvent>() {
                @Override
                public boolean matches(LogEvent event) {
                    if (contains(matchesText, event.getClassName(), event.getMessage(), event.getLogger(), event.getThread())) {
                        return true;
                    }
                    String[] throwableStrRep = event.getException();
                    if (throwableStrRep != null && contains(matchesText, throwableStrRep)) {
                        return true;
                    }
                    Map properties = event.getProperties();
                    if (properties != null && contains(matchesText, properties.toString())) {
                        return true;
                    }
                    return false;
                }
            });
        }

        if (predicates.size() == 0) {
            return null;
        } else if (predicates.size() == 1) {
            return predicates.get(0);
        } else {
            return new Predicate<LogEvent>() {
                @Override
                public String toString() {
                    return "AndPredicate" + predicates;
                }

                @Override
                public boolean matches(LogEvent event) {
                    for (Predicate<LogEvent> predicate : predicates) {
                        if (!predicate.matches(event)) {
                            return false;
                        }
                    }
                    return true;
                }
            };
        }
    }