public void runHousekeeping() {
        this.lock.readLock().lock();
        if (this.closed) {
            this.lock.readLock().unlock();
            return;
        }

        try (Connection c = getConnection()) {
            try (PreparedStatement ps = c.prepareStatement("DELETE FROM `" + getTableName() + "` WHERE (NOW() - `time` > 60)")) {
                ps.execute();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            this.lock.readLock().unlock();
        }
    }
An implementation of {@link Messenger} using SQL.
common/src/main/java/me/lucko/luckperms/common/messaging/sql/AbstractSqlMessenger.java