org.apache.hadoop.io

クラス AbstractMapWritable

java.lang.Object

org.apache.hadoop.io.AbstractMapWritable

すべての実装されたインタフェース:

Configurable, Writable

直系の既知のサブクラス:

MapWritable, SortedMapWritable

@InterfaceAudience.Public
 @InterfaceStability.Stable
public abstract class AbstractMapWritable
extends Object
implements Writable, Configurable

Abstract base class for MapWritable and SortedMapWritable Unlike org.apache.nutch.crawl.MapWritable, this class allows creation of MapWritable<Writable, MapWritable> so the CLASS_TO_ID and ID_TO_CLASS maps travel with the class instead of being static. Class ids range from 1 to 127 so there can be at most 127 distinct classes in any specific map instance.

コンストラクタのサマリー

コンストラクタ

修飾子	コンストラクタと説明
protected	AbstractMapWritable() constructor.

メソッドのサマリー

修飾子とタイプ	メソッドと説明
protected void	addToMap(Class<?> clazz) Add a Class to the maps if it is not already present.
protected void	copy(Writable other) Used by child copy constructors.
protected Class<?>	getClass(byte id)
Configuration	getConf() Return the configuration used by this object.
protected byte	getId(Class<?> clazz)
void	readFields(DataInput in) Deserialize the fields of this object from in.
void	setConf(Configuration conf) Set the configuration to be used by this object.
void	write(DataOutput out) Serialize the fields of this object to out.

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

AbstractMapWritable

protected AbstractMapWritable()

constructor.

メソッドの詳細

addToMap

protected void addToMap(Class<?> clazz)

Add a Class to the maps if it is not already present.

getClass

protected Class<?> getClass(byte id)

戻り値:

the Class class for the specified id

getId

protected byte getId(Class<?> clazz)

戻り値:

the id for the specified Class

copy

protected void copy(Writable other)

Used by child copy constructors.

getConf

public Configuration getConf()

インタフェースからコピーされた説明: Configurable

Return the configuration used by this object.

定義:

getConf インタフェース内 Configurable

戻り値:

the conf

setConf

public void setConf(Configuration conf)

インタフェースからコピーされた説明: Configurable

Set the configuration to be used by this object.

定義:

setConf インタフェース内 Configurable

パラメータ:

conf - the conf to set

write

public void write(DataOutput out)
           throws IOException

インタフェースからコピーされた説明: Writable

Serialize the fields of this object to out.

定義:

write インタフェース内 Writable

パラメータ:

out - DataOuput to serialize this object into.

例外:

IOException

readFields

public void readFields(DataInput in)
                throws IOException

インタフェースからコピーされた説明: Writable

Deserialize the fields of this object from in.

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

定義:

readFields インタフェース内 Writable

パラメータ:

in - DataInput to deseriablize this object from.

例外:

IOException