private void initWriter() {
        try {
            fileUrlWriter = new PrintWriter(new FileWriter(getFileName(fileUrlAllName), true));
            fileCursorWriter = new PrintWriter(new FileWriter(getFileName(fileCursor), false));
        } catch (IOException e) {
            throw new RuntimeException("init cache scheduler error", e);
        }
    }
Store urls and cursor in files so that a Spider can resume the status when shutdown.<br>

@author code4crafter@gmail.com <br>
@since 0.2.0
webmagic-extension/src/main/java/us/codecraft/webmagic/scheduler/FileCacheQueueScheduler.java