title: spring-xd how to use source:file read line one by one
body: <p>I have a stream that watch output of multi file in a directory, process data and put it to HDFS. Here is my stream creat command: </p>
  
  <pre><code>stream create --name fileHdfs --definition "file --dir=/var/log/supervisor/ --pattern=tracker.out-*.log --outputType=text/plain | logHdfsTransformer | hdfs --fsUri=hdfs://192.168.1.115:8020 --directory=/data/log/appsync --fileName=log --partitionPath=path(dateFormat('yyyy/MM/dd'))" --deploy
  </code></pre>
  
  <p>Problem is source:file module send all data read from file to log processing module instead of one line each turn, becase of that, payload string have millions of char, i can't process it. Ex:</p>
  
  <pre><code>--- PAYLOAD LENGTH---- 9511284
  </code></pre>
  
  <p>Please tell me how to read line by line when use source:file module, thanks !!!</p>