org.apache.hadoop.mapreduce.lib.output

类 SequenceFileAsBinaryOutputFormat

java.lang.Object

org.apache.hadoop.mapreduce.OutputFormat<K,V>

org.apache.hadoop.mapreduce.lib.output.FileOutputFormat<K,V>

org.apache.hadoop.mapreduce.lib.output.SequenceFileOutputFormat<BytesWritable,BytesWritable>

org.apache.hadoop.mapreduce.lib.output.SequenceFileAsBinaryOutputFormat

@InterfaceAudience.Public
@InterfaceStability.Stable
public class SequenceFileAsBinaryOutputFormat
extends SequenceFileOutputFormat<BytesWritable,BytesWritable>

An OutputFormat that writes keys, values to SequenceFiles in binary(raw) format

嵌套类概要

嵌套类

限定符和类型	类和说明
static class	SequenceFileAsBinaryOutputFormat.WritableValueBytes Inner class used for appendRaw

从类继承的嵌套类/接口 org.apache.hadoop.mapreduce.lib.output.FileOutputFormat

FileOutputFormat.Counter

字段概要

字段

限定符和类型	字段和说明
static String	KEY_CLASS
static String	VALUE_CLASS

从类继承的字段 org.apache.hadoop.mapreduce.lib.output.FileOutputFormat

BASE_OUTPUT_NAME, PART

构造器概要

构造器

构造器和说明
SequenceFileAsBinaryOutputFormat()

方法概要

方法

限定符和类型	方法和说明
void	checkOutputSpecs(JobContext job) Check for validity of the output-specification for the job.
RecordWriter<BytesWritable,BytesWritable>	getRecordWriter(TaskAttemptContext context) Get the RecordWriter for the given task.
static Class<? extends WritableComparable>	getSequenceFileOutputKeyClass(JobContext job) Get the key class for the SequenceFile
static Class<? extends Writable>	getSequenceFileOutputValueClass(JobContext job) Get the value class for the SequenceFile
protected SequenceFile.Writer	getSequenceWriter(TaskAttemptContext context, Class<?> keyClass, Class<?> valueClass)
static void	setSequenceFileOutputKeyClass(Job job, Class<?> theClass) Set the key class for the SequenceFile This allows the user to specify the key class to be different from the actual class (BytesWritable) used for writing
static void	setSequenceFileOutputValueClass(Job job, Class<?> theClass) Set the value class for the SequenceFile This allows the user to specify the value class to be different from the actual class (BytesWritable) used for writing

从类继承的方法 org.apache.hadoop.mapreduce.lib.output.SequenceFileOutputFormat

getOutputCompressionType, setOutputCompressionType

从类继承的方法 org.apache.hadoop.mapreduce.lib.output.FileOutputFormat

getCompressOutput, getDefaultWorkFile, getOutputCommitter, getOutputCompressorClass, getOutputName, getOutputPath, getPathForWorkFile, getUniqueFile, getWorkOutputPath, setCompressOutput, setOutputCompressorClass, setOutputName, setOutputPath

从类继承的方法 java.lang.Object

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

字段详细资料

KEY_CLASS

public static String KEY_CLASS

VALUE_CLASS

public static String VALUE_CLASS

构造器详细资料

SequenceFileAsBinaryOutputFormat

public SequenceFileAsBinaryOutputFormat()

方法详细资料

setSequenceFileOutputKeyClass

public static void setSequenceFileOutputKeyClass(Job job,
                                 Class<?> theClass)

Set the key class for the SequenceFile

This allows the user to specify the key class to be different from the actual class (BytesWritable) used for writing

参数:

job - the Job to modify

theClass - the SequenceFile output key class.

setSequenceFileOutputValueClass

public static void setSequenceFileOutputValueClass(Job job,
                                   Class<?> theClass)

Set the value class for the SequenceFile

This allows the user to specify the value class to be different from the actual class (BytesWritable) used for writing

参数:

job - the Job to modify

theClass - the SequenceFile output key class.

getSequenceFileOutputKeyClass

public static Class<? extends WritableComparable> getSequenceFileOutputKeyClass(JobContext job)

Get the key class for the SequenceFile

返回:

the key class of the SequenceFile

getSequenceFileOutputValueClass

public static Class<? extends Writable> getSequenceFileOutputValueClass(JobContext job)

Get the value class for the SequenceFile

返回:

the value class of the SequenceFile

getRecordWriter

public RecordWriter<BytesWritable,BytesWritable> getRecordWriter(TaskAttemptContext context)
                                                          throws IOException

从类复制的说明: OutputFormat

Get the RecordWriter for the given task.

覆盖:

getRecordWriter 在类中 SequenceFileOutputFormat<BytesWritable,BytesWritable>

参数:

context - the information about the current task.

返回:

a RecordWriter to write the output for the job.

抛出:

IOException

getSequenceWriter

protected SequenceFile.Writer getSequenceWriter(TaskAttemptContext context,
                                    Class<?> keyClass,
                                    Class<?> valueClass)
                                         throws IOException

抛出:

IOException

checkOutputSpecs

public void checkOutputSpecs(JobContext job)
                      throws IOException

从类复制的说明: OutputFormat

Check for validity of the output-specification for the job.

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.

覆盖:

checkOutputSpecs 在类中 FileOutputFormat<BytesWritable,BytesWritable>

参数:

job - information about the job

抛出:

IOException - when output should not be attempted