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java.lang.Objectorg.apache.hadoop.mapreduce.OutputFormat<K,V>
public abstract class OutputFormat<K,V>
OutputFormat describes the output-specification for a
Map-Reduce job.
The Map-Reduce framework relies on the OutputFormat of the
job to:
RecordWriter implementation to be used to write out
the output files of the job. Output files are stored in a
FileSystem.
RecordWriter| Constructor Summary | |
|---|---|
OutputFormat()
|
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| Method Summary | |
|---|---|
abstract void |
checkOutputSpecs(JobContext context)
Check for validity of the output-specification for the job. |
abstract OutputCommitter |
getOutputCommitter(TaskAttemptContext context)
Get the output committer for this output format. |
abstract RecordWriter<K,V> |
getRecordWriter(TaskAttemptContext context)
Get the RecordWriter for the given task. |
| Methods inherited from class java.lang.Object |
|---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
| Constructor Detail |
|---|
public OutputFormat()
| Method Detail |
|---|
public abstract RecordWriter<K,V> getRecordWriter(TaskAttemptContext context)
throws IOException,
InterruptedException
RecordWriter for the given task.
context - the information about the current task.
RecordWriter to write the output for the job.
IOException
InterruptedException
public abstract void checkOutputSpecs(JobContext context)
throws IOException,
InterruptedException
This is to validate the output specification for the job when it is a job is submitted. Typically checks that it does not already exist, throwing an exception when it already exists, so that output is not overwritten.
context - information about the job
IOException - when output should not be attempted
InterruptedException
public abstract OutputCommitter getOutputCommitter(TaskAttemptContext context)
throws IOException,
InterruptedException
context - the task context
IOException
InterruptedException
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