CursorFileManager对cursor文件的读写

public class CursorFileManager implements CursorManager{public void write(String key, LongCursor cursor) throws IOException
    {
        File file = new File(key);
        if (cursor == null) {
            if (file.exists()) {
                file.delete();
            }
            return;
        }
 
    FileWriter fileWriter = null;
    try {
        fileWriter = new FileWriter(file);
        JSON.writeJSONStringTo(cursor, fileWriter, new SerializerFeature[0]);
    } catch (Exception e) {
        this.logger.error(e.getMessage(), e);
    } finally {
        if (fileWriter != null)
            fileWriter.close();
    }
  }
 
public LongCursor read(String key){
    JSONReader reader = null;
    try {
        File file = new File(key);
        this.logger.info("try to read cursor from file={}", file.getAbsolutePath());
        if (!file.exists()) {
            return null;
        }
        reader = new JSONReader(new FileReader(file));
        LongCursor cursor = (LongCursor)reader.readObject(LongCursor.class);
        return cursor;
    } catch (Exception e) {
        this.logger.error(e.getMessage(), e);
    } finally {
        if (reader != null)
          reader.close();
    }
    return null;
}

cursor格式：

{"biz":"false-0","extraInfo":1469203484000,"from":1469203208000,"to":1469203508000}

public LongCursor read() {
    LongCursor cursor = cursorManager.read(cursorPath + "/" + fileName);
    if (cursor != null) {
        String biz = cursor.getBiz();
        if (biz != null && biz.length() > 0) {
            String[] secs = biz.split("-");
            shouldWait = Boolean.parseBoolean(secs[0]);
            if (secs.length > 1) {
                completedOrderId = Long.valueOf(secs[1]);
            }
        }
    }
    return cursor;
}
 
public void write(LongCursor cursor) throws IOException {
    cursor.setBiz(shouldWait + "-" + completedOrderId);
    cursorManager.write(cursorPath + "/" + fileName, cursor);
}