The HDFS data reading process includes the following steps, please choose the correct order.

After obtaining this input stream, the client calls the read method to read the data. The input stream selects the nearest DataNode to establish a connection and read data.

The client calls close. to close the input stream.

The location where the data block corresponding to this file in NameNodel is obtained by calling NameNode remotely through RPC

If the end of the data block has been reached. Then close the connection with this DataNodel, and then re-find the next data block. until all data is read.

The client calls the open method of the FileSystem instance to obtain the input stream corresponding to the file.