org.apache.hadoop.mapreduce

类 JobID

java.lang.Object

org.apache.hadoop.mapreduce.ID

org.apache.hadoop.mapred.ID

org.apache.hadoop.mapreduce.JobID

所有已实现的接口:

Comparable<ID>, Writable, WritableComparable<ID>

直接已知子类:

JobID

public class JobID
extends ID
implements Comparable<ID>

JobID represents the immutable and unique identifier for the job. JobID consists of two parts. First part represents the jobtracker identifier, so that jobID to jobtracker map is defined. For cluster setup this string is the jobtracker start time, for local setting, it is "local". Second part of the JobID is the job number.
An example JobID is : job_200707121733_0003 , which represents the third job running at the jobtracker started at 200707121733.

Applications should never construct or parse JobID strings, but rather use appropriate constructors or forName(String) method.

另请参阅:

TaskID, TaskAttemptID, JobTracker.getNewJobId(), JobTracker.getStartTime()

字段概要

字段

限定符和类型	字段和说明
protected static NumberFormat	idFormat
protected static String	JOB
static String	JOBID_REGEX

从类继承的字段 org.apache.hadoop.mapreduce.ID

id, SEPARATOR

构造器概要

构造器

构造器和说明
JobID()
JobID(String jtIdentifier, int id) Constructs a JobID object

方法概要

方法

限定符和类型	方法和说明
StringBuilder	appendTo(StringBuilder builder) Add the stuff after the "job" prefix to the given builder.
int	compareTo(ID o) Compare JobIds by first jtIdentifiers, then by job numbers
boolean	equals(Object o)
static JobID	forName(String str) Construct a JobId object from given string
String	getJtIdentifier()
int	hashCode()
void	readFields(DataInput in) Deserialize the fields of this object from in.
String	toString()
void	write(DataOutput out) Serialize the fields of this object to out.

从类继承的方法 org.apache.hadoop.mapreduce.ID

getId

从类继承的方法 java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

字段详细资料

JOB

protected static final String JOB

另请参阅:

常量字段值

JOBID_REGEX

public static final String JOBID_REGEX

另请参阅:

常量字段值

idFormat

protected static final NumberFormat idFormat

构造器详细资料

JobID

public JobID(String jtIdentifier,
     int id)

Constructs a JobID object

参数:

jtIdentifier - jobTracker identifier

id - job number

JobID

public JobID()

方法详细资料

getJtIdentifier

public String getJtIdentifier()

equals

public boolean equals(Object o)

覆盖:

equals 在类中 ID

compareTo

public int compareTo(ID o)

Compare JobIds by first jtIdentifiers, then by job numbers

指定者:

compareTo 在接口中 Comparable<ID>

覆盖:

compareTo 在类中 ID

appendTo

public StringBuilder appendTo(StringBuilder builder)

Add the stuff after the "job" prefix to the given builder. This is useful, because the sub-ids use this substring at the start of their string.

参数:

builder - the builder to append to

返回:

the builder that was passed in

hashCode

public int hashCode()

覆盖:

hashCode 在类中 ID

toString

public String toString()

覆盖:

toString 在类中 ID

readFields

public void readFields(DataInput in)
                throws IOException

从接口复制的说明: Writable

Deserialize the fields of this object from in.

For efficiency, implementations should attempt to re-use storage in the existing object where possible.

指定者:

readFields 在接口中 Writable

覆盖:

readFields 在类中 ID

参数:

in - DataInput to deseriablize this object from.

抛出:

IOException

write

public void write(DataOutput out)
           throws IOException

从接口复制的说明: Writable

Serialize the fields of this object to out.

指定者:

write 在接口中 Writable

覆盖:

write 在类中 ID

参数:

out - DataOuput to serialize this object into.

抛出:

IOException

forName

public static JobID forName(String str)
                     throws IllegalArgumentException

Construct a JobId object from given string

返回:

constructed JobId object or null if the given String is null

抛出:

IllegalArgumentException - if the given string is malformed