Time for action – using ChainMapper for field validation/analysis

Let's use this principle and employ the ChainMapper class to help us provide some record validation within our job:

1. Create the following class as UFORecordValidationMapper.java:

   import java.io.IOException;
   
   import org.apache.hadoop.io.* ;
   import org.apache.hadoop.mapred.* ;
   import org.apache.hadoop.mapred.lib.* ;
   
   public class UFORecordValidationMapper extends MapReduceBase
   implements Mapper<LongWritable, Text, LongWritable, Text>
   {
   
       public void map(LongWritable key, Text value,
           OutputCollector<LongWritable, Text> output,
           Reporter reporter) throws IOException
   {
   String line = value.toString();
           if (validate(line))
               output.collect(key, value);
       }
   
           private boolean validate(String str)
           {
               String[] parts = str.split("\t") ;
   
               if (parts.length != 6)
               return false ;
   
               return true ;
           }
       }

2. Create the following as...