title: Custom Map Reduce Program on Hive, what's the Rule? How about input and output?
body: <p>I got stuck for a few days because I want to create a custom map reduce program based on my query on hive, I found not many examples after googling and I'm still confused about the rule.</p>
  
  <p>What is the rule to create my custom mapreduce program, how about the mapper and reducer class?</p>
  
  <p>Can anyone provide any solution?</p>
  
  <p>I want to develop this program in Java, but I'm still stuck ,and then when formatting output in collector, how do I format the result in mapper and reducer class?</p>
  
  <p>Does anybody want to give me some example and explanation about this kind of stuff?</p>