org.apache.hadoop.mapred: public class: MapRunner

org.apache.hadoop.mapred
public class: MapRunner [javadoc | source]

java.lang.Object
   org.apache.hadoop.mapred.MapRunner

All Implemented Interfaces:
MapRunnable

Direct Known Subclasses:
PipesMapRunner

Default MapRunnable implementation.

Method from org.apache.hadoop.mapred.MapRunner Summary:
configure, run

Methods from java.lang.Object:
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method from org.apache.hadoop.mapred.MapRunner Detail:
public void configure(JobConf job) { this.mapper = (Mapper)ReflectionUtils.newInstance(job.getMapperClass(), job); }
public void run(RecordReader input, OutputCollector output, Reporter reporter) throws IOException { try { // allocate key & value instances that are re-used for all entries WritableComparable key = input.createKey(); Writable value = input.createValue(); while (input.next(key, value)) { // map pair to output mapper.map(key, value, output, reporter); } } finally { mapper.close(); } }

Method from org.apache.hadoop.mapred.MapRunner Detail:

 public  void configure(JobConf job) {
    this.mapper = (Mapper)ReflectionUtils.newInstance(job.getMapperClass(),
                                                      job);
}

 public  void run(RecordReader input,
    OutputCollector output,
    Reporter reporter) throws IOException {
    try {
      // allocate key & value instances that are re-used for all entries
      WritableComparable key = input.createKey();
      Writable value = input.createValue();
      while (input.next(key, value)) {
        // map pair to output
        mapper.map(key, value, output, reporter);
      }
    } finally {
      mapper.close();
    }
}