org.apache.hadoop.io

类 VersionedWritable

java.lang.Object

org.apache.hadoop.io.VersionedWritable

所有已实现的接口:

Writable

public abstract class VersionedWritable
extends Object
implements Writable

A base class for Writables that provides version checking.

This is useful when a class may evolve, so that instances written by the old version of the class may still be processed by the new version. To handle this situation, readFields(DataInput) implementations should catch VersionMismatchException.

构造器概要

构造器

构造器和说明
VersionedWritable()

方法概要

方法

限定符和类型	方法和说明
abstract byte	getVersion() Return the version number of the current implementation.
void	readFields(DataInput in) Deserialize the fields of this object from in.
void	write(DataOutput out) Serialize the fields of this object to out.

从类继承的方法 java.lang.Object

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

构造器详细资料

VersionedWritable

public VersionedWritable()

方法详细资料

getVersion

public abstract byte getVersion()

Return the version number of the current implementation.

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

参数:

out - DataOuput to serialize this object into.

抛出:

IOException

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

参数:

in - DataInput to deseriablize this object from.

抛出:

IOException