public class IdentityLocalAnalysis extends Object implements ILocalAnalysis<DocumentID,DocumentAndOp>
| 构造器和说明 |
|---|
IdentityLocalAnalysis() |
| 限定符和类型 | 方法和说明 |
|---|---|
void |
close() |
void |
configure(JobConf job)
Initializes a new instance from a
JobConf. |
void |
map(DocumentID key,
DocumentAndOp value,
OutputCollector<DocumentID,DocumentAndOp> output,
Reporter reporter)
Maps a single input key/value pair into an intermediate key/value pair.
|
public void map(DocumentID key, DocumentAndOp value, OutputCollector<DocumentID,DocumentAndOp> output, Reporter reporter) throws IOException
MapperOutput pairs need not be of the same types as input pairs. A given
input pair may map to zero or many output pairs. Output pairs are
collected with calls to
OutputCollector.collect(Object,Object).
Applications can use the Reporter provided to report progress
or just indicate that they are alive. In scenarios where the application
takes an insignificant amount of time to process individual key/value
pairs, this is crucial since the framework might assume that the task has
timed-out and kill that task. The other way of avoiding this is to set
mapred.task.timeout to a high-enough value (or even zero for no
time-outs).
map 在接口中 Mapper<DocumentID,DocumentAndOp,DocumentID,DocumentAndOp>key - the input key.value - the input value.output - collects mapped keys and values.reporter - facility to report progress.IOExceptionpublic void configure(JobConf job)
JobConfigurableJobConf.configure 在接口中 JobConfigurablejob - the configurationpublic void close()
throws IOException
close 在接口中 Closeableclose 在接口中 AutoCloseableIOExceptionCopyright © 2009 The Apache Software Foundation