org.apache.hadoop.io

类 BytesWritable

java.lang.Object

org.apache.hadoop.io.BinaryComparable

org.apache.hadoop.io.BytesWritable

所有已实现的接口:

Comparable<BinaryComparable>, Writable, WritableComparable<BinaryComparable>

直接已知子类:

TypedBytesWritable

public class BytesWritable
extends BinaryComparable
implements WritableComparable<BinaryComparable>

A byte sequence that is usable as a key or value. It is resizable and distinguishes between the size of the seqeunce and the current capacity. The hash function is the front of the md5 of the buffer. The sort order is the same as memcmp.

嵌套类概要

嵌套类

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

构造器概要

构造器

构造器和说明
BytesWritable() Create a zero-size sequence.
BytesWritable(byte[] bytes) Create a BytesWritable using the byte array as the initial value.

方法概要

方法

限定符和类型	方法和说明
boolean	equals(Object right_obj) Are the two byte sequences equal?
byte[]	get() 已过时。 Use getBytes() instead.
byte[]	getBytes() Get the data from the BytesWritable.
int	getCapacity() Get the capacity, which is the maximum size that could handled without resizing the backing storage.
int	getLength() Get the current size of the buffer.
int	getSize() 已过时。 Use getLength() instead.
int	hashCode() Return a hash of the bytes returned from {#getBytes()}.
void	readFields(DataInput in) Deserialize the fields of this object from in.
void	set(byte[] newData, int offset, int length) Set the value to a copy of the given byte range
void	set(BytesWritable newData) Set the BytesWritable to the contents of the given newData.
void	setCapacity(int new_cap) Change the capacity of the backing storage.
void	setSize(int size) Change the size of the buffer.
String	toString() Generate the stream of bytes as hex pairs separated by ' '.
void	write(DataOutput out) Serialize the fields of this object to out.

从类继承的方法 org.apache.hadoop.io.BinaryComparable

compareTo, compareTo

从类继承的方法 java.lang.Object

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

从接口继承的方法 java.lang.Comparable

compareTo

构造器详细资料

BytesWritable

public BytesWritable()

Create a zero-size sequence.

BytesWritable

public BytesWritable(byte[] bytes)

Create a BytesWritable using the byte array as the initial value.

参数:

bytes - This array becomes the backing storage for the object.

方法详细资料

getBytes

public byte[] getBytes()

Get the data from the BytesWritable.

指定者:

getBytes 在类中 BinaryComparable

返回:

The data is only valid between 0 and getLength() - 1.

get

@Deprecated
public byte[] get()

已过时。 Use getBytes() instead.

Get the data from the BytesWritable.

getLength

public int getLength()

Get the current size of the buffer.

指定者:

getLength 在类中 BinaryComparable

getSize

@Deprecated
public int getSize()

已过时。 Use getLength() instead.

Get the current size of the buffer.

setSize

public void setSize(int size)

Change the size of the buffer. The values in the old range are preserved and any new values are undefined. The capacity is changed if it is necessary.

参数:

size - The new number of bytes

getCapacity

public int getCapacity()

Get the capacity, which is the maximum size that could handled without resizing the backing storage.

返回:

The number of bytes

setCapacity

public void setCapacity(int new_cap)

Change the capacity of the backing storage. The data is preserved.

参数:

new_cap - The new capacity in bytes.

set

public void set(BytesWritable newData)

Set the BytesWritable to the contents of the given newData.

参数:

newData - the value to set this BytesWritable to.

set

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

Set the value to a copy of the given byte range

参数:

newData - the new values to copy in

offset - the offset in newData to start at

length - the number of bytes to copy

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

hashCode

public int hashCode()

从类复制的说明: BinaryComparable

Return a hash of the bytes returned from {#getBytes()}.

覆盖:

hashCode 在类中 BinaryComparable

另请参阅:

WritableComparator.hashBytes(byte[],int)

equals

public boolean equals(Object right_obj)

Are the two byte sequences equal?

覆盖:

equals 在类中 BinaryComparable

toString

public String toString()

Generate the stream of bytes as hex pairs separated by ' '.

覆盖:

toString 在类中 Object