org.apache.hadoop.io

类 ObjectWritable

java.lang.Object

org.apache.hadoop.io.ObjectWritable

所有已实现的接口:

Configurable, Writable

public class ObjectWritable
extends Object
implements Writable, Configurable

A polymorphic Writable that writes an instance with it's class name. Handles arrays, strings and primitive types without a Writable wrapper.

构造器概要

构造器

构造器和说明
ObjectWritable()
ObjectWritable(Class declaredClass, Object instance)
ObjectWritable(Object instance)

方法概要

方法

限定符和类型	方法和说明
Object	get() Return the instance, or null if none.
Configuration	getConf() Return the configuration used by this object.
Class	getDeclaredClass() Return the class this is meant to be.
void	readFields(DataInput in) Deserialize the fields of this object from in.
static Object	readObject(DataInput in, Configuration conf) Read a Writable, String, primitive type, or an array of the preceding.
static Object	readObject(DataInput in, ObjectWritable objectWritable, Configuration conf) Read a Writable, String, primitive type, or an array of the preceding.
void	set(Object instance) Reset the instance.
void	setConf(Configuration conf) Set the configuration to be used by this object.
String	toString()
void	write(DataOutput out) Serialize the fields of this object to out.
static void	writeObject(DataOutput out, Object instance, Class declaredClass, Configuration conf) Write a Writable, String, primitive type, or an array of the preceding.

从类继承的方法 java.lang.Object

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

构造器详细资料

ObjectWritable

public ObjectWritable()

ObjectWritable

public ObjectWritable(Object instance)

ObjectWritable

public ObjectWritable(Class declaredClass,
              Object instance)

方法详细资料

get

public Object get()

Return the instance, or null if none.

getDeclaredClass

public Class getDeclaredClass()

Return the class this is meant to be.

set

public void set(Object instance)

Reset the instance.

toString

public String toString()

覆盖:

toString 在类中 Object

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

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

writeObject

public static void writeObject(DataOutput out,
               Object instance,
               Class declaredClass,
               Configuration conf)
                        throws IOException

Write a Writable, String, primitive type, or an array of the preceding.

抛出:

IOException

readObject

public static Object readObject(DataInput in,
                Configuration conf)
                         throws IOException

Read a Writable, String, primitive type, or an array of the preceding.

抛出:

IOException

readObject

public static Object readObject(DataInput in,
                ObjectWritable objectWritable,
                Configuration conf)
                         throws IOException

Read a Writable, String, primitive type, or an array of the preceding.

抛出:

IOException

setConf

public void setConf(Configuration conf)

从接口复制的说明: Configurable

Set the configuration to be used by this object.

指定者:

setConf 在接口中 Configurable

getConf

public Configuration getConf()

从接口复制的说明: Configurable

Return the configuration used by this object.

指定者:

getConf 在接口中 Configurable