org.apache.hadoop.io

类 NullWritable

java.lang.Object

org.apache.hadoop.io.NullWritable

所有已实现的接口:

Comparable, Writable, WritableComparable

public class NullWritable
extends Object
implements WritableComparable

Singleton Writable with no data.

嵌套类概要

嵌套类

限定符和类型	类和说明
static class	NullWritable.Comparator A Comparator "optimized" for NullWritable.

方法概要

方法

限定符和类型	方法和说明
int	compareTo(Object other)
boolean	equals(Object other)
static NullWritable	get() Returns the single instance of this class.
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 java.lang.Object

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

方法详细资料

get

public static NullWritable get()

Returns the single instance of this class.

toString

public String toString()

覆盖:

toString 在类中 Object

hashCode

public int hashCode()

覆盖:

hashCode 在类中 Object

compareTo

public int compareTo(Object other)

指定者:

compareTo 在接口中 Comparable

equals

public boolean equals(Object other)

覆盖:

equals 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