title: Spring Integration:Is there a way to aggregate from "all" messages in a channel?
body: <p>I want to write a batch which reads website access log files(csv file)from a path every day and do some analysis using spring integration.</p>
  
  <p>this is the simplified version of the input csv file.</p>
  
  <pre>
  srcIp1,t1,path1
  srcIp2,t2,path2
  srcIp1,t3,path2
  srcIp1,t4,path1
  </pre>
  
  <p>The access number per source ip and path is to be calculated after some filtering logic.</p>
  
  <p>I made a input channel whose payload is the parsed log line,and a filter is applied,and finally an aggregator to calculate the final result.
  The problem is what should be the right group release stragety,the default release stragety(SequenceSizeReleaseStrategy) does not work.</p>
  
  <p>Also any of other spring integraion out of box release  </p>
  
  <blockquote>
    <p>strategies(ExpressionEvaluatingReleaseStrategy,
    MessageCountReleaseStrategy, MethodInvokingReleaseStrategy,
    SequenceSizeReleaseStrategy, TimeoutCountSequenceSizeReleaseStrategy)</p>
  </blockquote>
  
  <p>does not seem to fit my needs.</p>
  
  <p>Or Spring integration assumed that a channel carries a message stream where there is no concept of "ending of message" and is not suitalbe for my problem here ?</p>