org.apache.hadoop.mapred.lib.db

クラス DBOutputFormat<K extends DBWritable,V>

java.lang.Object

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

org.apache.hadoop.mapreduce.lib.db.DBOutputFormat<K,V>

org.apache.hadoop.mapred.lib.db.DBOutputFormat<K,V>

すべての実装されたインタフェース:

OutputFormat<K,V>

@InterfaceAudience.Public
 @InterfaceStability.Stable
public class DBOutputFormat<K extends DBWritable,V>
extends DBOutputFormat<K,V>
implements OutputFormat<K,V>

コンストラクタのサマリー

コンストラクタ

コンストラクタと説明
DBOutputFormat()

メソッドのサマリー

修飾子とタイプ	メソッドと説明
void	checkOutputSpecs(FileSystem filesystem, JobConf job) Check for validity of the output-specification for the job.
RecordWriter<K,V>	getRecordWriter(FileSystem filesystem, JobConf job, String name, Progressable progress) Get the RecordWriter for the given job.
static void	setOutput(JobConf job, String tableName, int fieldCount) Initializes the reduce-part of the job with the appropriate output settings
static void	setOutput(JobConf job, String tableName, String... fieldNames) Initializes the reduce-part of the job with the appropriate output settings

クラスから継承されたメソッド org.apache.hadoop.mapreduce.lib.db.DBOutputFormat

checkOutputSpecs, constructQuery, getOutputCommitter, getRecordWriter, setOutput, setOutput

クラスから継承されたメソッド java.lang.Object

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

コンストラクタの詳細

DBOutputFormat

public DBOutputFormat()

メソッドの詳細

checkOutputSpecs

public void checkOutputSpecs(FileSystem filesystem,
                             JobConf job)
                      throws IOException

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.

定義:

checkOutputSpecs インタフェース内 OutputFormat<K extends DBWritable,V>

job - job configuration.

例外:

IOException - when output should not be attempted

getRecordWriter

public RecordWriter<K,V> getRecordWriter(FileSystem filesystem,
                                         JobConf job,
                                         String name,
                                         Progressable progress)
                                  throws IOException

Get the RecordWriter for the given job.

定義:

getRecordWriter インタフェース内 OutputFormat<K extends DBWritable,V>

job - configuration for the job whose output is being written.

name - the unique name for this part of the output.

progress - mechanism for reporting progress while writing to file.

戻り値:

a RecordWriter to write the output for the job.

例外:

IOException

setOutput

public static void setOutput(JobConf job,
                             String tableName,
                             String... fieldNames)

Initializes the reduce-part of the job with the appropriate output settings

パラメータ:

job - The job

tableName - The table to insert data into

fieldNames - The field names in the table.

setOutput

public static void setOutput(JobConf job,
                             String tableName,
                             int fieldCount)

Initializes the reduce-part of the job with the appropriate output settings

パラメータ:

job - The job

tableName - The table to insert data into

fieldCount - the number of fields in the table.