org.apache.nutch.mapReduce
Class Task

java.lang.Object
  org.apache.nutch.mapReduce.Task

All Implemented Interfaces:

Writable

Direct Known Subclasses:

MapTask, ReduceTask

public abstract class Task

extends Object

implements Writable

Base class for tasks.

Constructor Summary

Task()

Task(String jobFile, String taskId)

Method Summary

abstract org.apache.nutch.mapReduce.TaskRunner	createRunner(TaskTracker tracker) Return an approprate thread runner for this task.
String	getJobFile()
String	getTaskId()
void	readFields(DataInput in) Reads the fields of this object from in.
abstract void	run(JobConf job, TaskUmbilicalProtocol umbilical) Run this task as a part of the named job.
void	setJobFile(String jobFile)
String	toString()
void	write(DataOutput out) Writes the fields of this object to out.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Task

public Task()

Task

public Task(String jobFile,
            String taskId)

Method Detail

setJobFile

public void setJobFile(String jobFile)

getJobFile

public String getJobFile()

getTaskId

public String getTaskId()

write

public void write(DataOutput out)
           throws IOException

Description copied from interface: Writable

Writes the fields of this object to out.

Specified by:

write in interface Writable

Throws:

IOException

readFields

public void readFields(DataInput in)
                throws IOException

Description copied from interface: Writable

Reads the fields of this object from in. For efficiency, implementations should attempt to re-use storage in the existing object where possible.

Specified by:

readFields in interface Writable

Throws:

IOException

toString

public String toString()

run

public abstract void run(JobConf job,
                         TaskUmbilicalProtocol umbilical)
                  throws IOException

Run this task as a part of the named job. This method is executed in the child process and is what invokes user-supplied map, reduce, etc. methods.

Parameters:

umbilical - for progress reports

Throws:

IOException

createRunner

public abstract org.apache.nutch.mapReduce.TaskRunner createRunner(TaskTracker tracker)

Return an approprate thread runner for this task.