Java 类org.bson.BasicBSONCallback 实例源码

@Override
public void displayFile(
        FileSystem fs, 
        Path path, 
        OutputStream outStream, 
        int startLine, 
        int endLine) throws IOException {

    FSDataInputStream in = null;
    try {
        in = fs.open(path, 16 * 1024 * 1024);

        long endTime = System.currentTimeMillis() + STOP_TIME;

        BasicBSONCallback callback = new BasicBSONCallback();
        BasicBSONDecoder decoder = new BasicBSONDecoder();

        /*
         * keep reading and rendering bsonObjects until one of these conditions is met:
         * 
         * a. we have rendered all bsonObjects desired.
         * b. we have run out of time.
         */
        for (int lineno = 1; lineno <= endLine && System.currentTimeMillis() <= endTime; lineno++) {
            if (lineno < startLine) {
                continue;
            }

            callback.reset();
            decoder.decode(in, callback);

            BSONObject value = (BSONObject) callback.get();

            StringBuilder bldr = new StringBuilder();
            bldr.append("\n\n Record ");
            bldr.append(lineno);
            bldr.append('\n');
            JSON.serialize(value, bldr);
            outStream.write(bldr.toString().getBytes("UTF-8"));
        }
    }
    catch (IOException e) {
        outStream.write(("Error in display avro file: " + e.getLocalizedMessage()).getBytes("UTF-8"));
    }
    finally {
        if (in != null) {
            in.close();
        }
        outStream.flush();
    }
}

@Override
public void displayFile(FileSystem fs, Path path, OutputStream outStream,
    int startLine, int endLine) throws IOException {

  FSDataInputStream in = null;
  try {
    in = fs.open(path, 16 * 1024 * 1024);

    long endTime = System.currentTimeMillis() + STOP_TIME;

    BasicBSONCallback callback = new BasicBSONCallback();
    BasicBSONDecoder decoder = new BasicBSONDecoder();

    /*
     * keep reading and rendering bsonObjects until one of these conditions is
     * met:
     *
     * a. we have rendered all bsonObjects desired. b. we have run out of
     * time.
     */
    for (int lineno = 1; lineno <= endLine
        && System.currentTimeMillis() <= endTime; lineno++) {
      if (lineno < startLine) {
        continue;
      }

      callback.reset();
      decoder.decode(in, callback);

      BSONObject value = (BSONObject) callback.get();

      StringBuilder bldr = new StringBuilder();
      bldr.append("\n\n Record ");
      bldr.append(lineno);
      bldr.append('\n');
      JSON.serialize(value, bldr);
      outStream.write(bldr.toString().getBytes("UTF-8"));
    }
  } catch (IOException e) {
    outStream
        .write(("Error in display avro file: " + e.getLocalizedMessage())
            .getBytes("UTF-8"));
  } finally {
    if (in != null) {
      in.close();
    }
    outStream.flush();
  }
}