Writing Data into a File

Function

The process of writing data into a file is

1. Use the create method in the FileSystem instance to obtain the output stream of writing files.
2. Uses this data stream to write content into a specified file in the HDFS.

Close all requested resources after writing files.

Example Codes

The following is code snippets. For complete codes, see HdfsMain and HdfsWriter classes in com.huawei.bigdata.hdfs.examples.

/**
 * Write a file, write the data
 *
 * @throws IOException
 * @throws ParameterException 
 */
private void write() throws IOException {
   final String content = "hi, I am bigdata. It is successful if you can see me.";
   FSDataOutputStream out = null;
   try {
       out = fSystem.create(new Path(DEST_PATH + File.separator + FILE_NAME));
       out.write(content.getBytes());
       out.hsync();
       LOG.info("success to write.");
   } finally {
    // make sure the stream is closed finally.
    IOUtils.closeStream(out);
  }
}