com.aliyun.odps.io

Class BytesWritable

java.lang.Object

com.aliyun.odps.io.BinaryComparable

com.aliyun.odps.io.BytesWritable

All Implemented Interfaces:

Writable, WritableComparable<BinaryComparable>, Comparable<BinaryComparable>

public class BytesWritable
extends BinaryComparable
implements WritableComparable<BinaryComparable>

BytesWritable 提供了 byte[] 的 Writable 和 WritableComparable 的实现.

Nested Class Summary

Nested Classes

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

Constructor Summary

Constructors

Constructor and Description
BytesWritable() 默认构造 空 byte[] 的 BytesWritable.
BytesWritable(byte[] bytes) 构造值为给定 byte 数组的 BytesWritable.

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object right_obj) 判断两个 BytesWritable 内容是否相同.
byte[]	getBytes() 返回此 byte 数组的内容
int	getCapacity() 获取字节数组容量.
int	getLength() 返回内容长度.
int	hashCode() 计算二进制内容的哈希值.
void	readFields(DataInput in) 从指定的 DataInput in 反序列化.
void	set(byte[] newData, int offset, int length) 更新数据内容为给定字节数组中的数据.
void	set(BytesWritable newData) 更新数据内容为给定 BytesWritable 的数据.
void	setCapacity(int new_cap) 更该字节数组容量
void	setSize(int size) 更改数组内容长度.
String	toString() 输出数据的十六进制内容.
void	write(DataOutput out) 序列化到指定的 DataOutput out.

Methods inherited from class com.aliyun.odps.io.BinaryComparable

compareTo, compareTo

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.lang.Comparable

compareTo

Constructor Detail

BytesWritable

public BytesWritable()

默认构造 空 byte[] 的 BytesWritable.

BytesWritable

public BytesWritable(byte[] bytes)

构造值为给定 byte 数组的 BytesWritable.

Parameters:

bytes -

Method Detail

getBytes

public byte[] getBytes()

返回此 byte 数组的内容

Specified by:

getBytes in class BinaryComparable

Returns:

此 byte 数组的内容，数据只有在 bytes[0, getLength() - 1]直接有效

getLength

public int getLength()

返回内容长度.

Specified by:

getLength in class BinaryComparable

Returns:

二进制内容长度，单位：字节

setSize

public void setSize(int size)

更改数组内容长度.

注意：更改后，有效数据内容只由bytes[0, 更改前 getLength() -1]， 新增加的数组内容是未定义的，数组的容量按需增加。

Parameters:

size - 新内容长度

getCapacity

public int getCapacity()

获取字节数组容量.

Returns:

字节数组容量，即：bytes.length.

setCapacity

public void setCapacity(int new_cap)

更该字节数组容量

Parameters:

new_cap - 新容量大小

set

public void set(BytesWritable newData)

更新数据内容为给定 BytesWritable 的数据.

等价于：set(newData.getBytes(), 0, newData.getLength())

Parameters:

newData - 新数据

set

public void set(byte[] newData,
                int offset,
                int length)

更新数据内容为给定字节数组中的数据.

Parameters:

newData - 源数组

offset - 数据内容在 newData 中的偏移量

length - 数据内容长度

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

hashCode

public int hashCode()

Description copied from class: BinaryComparable

计算二进制内容的哈希值.

直接使用 {@link WritableComparator#hashBytes(byte[], int)进行计算

Overrides:

hashCode in class BinaryComparable

equals

public boolean equals(Object right_obj)

判断两个 BytesWritable 内容是否相同.

Overrides:

equals in class BinaryComparable

Parameters:

right_obj -

Returns:

如果两个都是 BytesWritable 且内容相同，返回true，否则返回false

toString

public String toString()

输出数据的十六进制内容.

Overrides:

toString in class Object