com.aliyun.odps.io

Class LongWritable

java.lang.Object

com.aliyun.odps.io.LongWritable

All Implemented Interfaces:

Writable, WritableComparable, Comparable

public class LongWritable
extends Object
implements WritableComparable

LongWritable 提供了 long 的 Writable 和 WritableComparable 的实现

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	LongWritable.Comparator LongWritable 对象的 WritableComparator 自然顺序实现（升序）.
static class	LongWritable.DecreasingComparator LongWritable 对象的 WritableComparator 降序实现.

Constructor Summary

Constructors

Constructor and Description
LongWritable() 默认构造 long 值为0的 LongWritable.
LongWritable(long value) 构造 long 值为给定 value 的 LongWritable.

Method Summary

Modifier and Type	Method and Description
int	compareTo(Object o) 比较两个 LongWritable 的值.
boolean	equals(Object o) 判断两个 LongWritable 是否相等.
long	get() 返回此 LongWritable 的值
int	hashCode() 计算哈希值，直接返回此 LongWritable 的值.
void	readFields(DataInput in) 从指定的 DataInput in 反序列化.
void	set(long value) 设置 LongWritable 的值
String	toString()
void	write(DataOutput out) 序列化到指定的 DataOutput out.

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

LongWritable

public LongWritable()

默认构造 long 值为0的 LongWritable.

LongWritable

public LongWritable(long value)

构造 long 值为给定 value 的 LongWritable.

Parameters:

value -

Method Detail

set

public void set(long value)

设置 LongWritable 的值

Parameters:

value -

get

public long get()

返回此 LongWritable 的值

Returns:

readFields

public void readFields(DataInput in)
                throws IOException

Description copied from interface: Writable

从指定的 DataInput in 反序列化.

Specified by:

readFields in interface Writable

Throws:

IOException

write

public void write(DataOutput out)
           throws IOException

Description copied from interface: Writable

序列化到指定的 DataOutput out.

Specified by:

write in interface Writable

Throws:

IOException

equals

public boolean equals(Object o)

判断两个 LongWritable 是否相等.

如果两个都是 LongWritable 且值相等，返回true，否则返回false

Overrides:

equals in class Object

Parameters:

o -

Returns:

hashCode

public int hashCode()

计算哈希值，直接返回此 LongWritable 的值.

Overrides:

hashCode in class Object

compareTo

public int compareTo(Object o)

比较两个 LongWritable 的值.

Specified by:

compareTo in interface Comparable

Parameters:

o - 比较对象

Returns:

(this < o ? -1 : (this == o) ? 0 ：1))

toString

public String toString()

Overrides:

toString in class Object