BytesWritable (Apache Hadoop Common 3.4.1.200-dep-1000 API)

java.lang.Object
- org.apache.hadoop.io.BinaryComparable
- - org.apache.hadoop.io.BytesWritable

All Implemented Interfaces:

java.lang.Comparable<BinaryComparable>, Writable, WritableComparable<BinaryComparable>
```
@Public
@Stable
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 sequence and the current capacity. The hash function is the front of the md5 of the buffer. The sort order is the same as memcmp.

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static class BytesWritable.Comparator
A Comparator optimized for BytesWritable.

Nested Classes
Modifier and Type	Class	Description
`static class`	`BytesWritable.Comparator`	A Comparator optimized for BytesWritable.

Constructor Summary

Constructors
Constructor	Description
`BytesWritable()`	Create a zero-size sequence.
`BytesWritable(byte[] bytes)`	Create a BytesWritable using the byte array as the initial value.
`BytesWritable(byte[] bytes, int length)`	Create a BytesWritable using the byte array as the initial value and length as the length.

Method Summary

All Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method	Description
`byte[]`	`copyBytes()`	Get a copy of the bytes that is exactly the length of the data.
`boolean`	`equals(java.lang.Object right_obj)`	Are the two byte sequences equal?
`byte[]`	`get()`	Deprecated. Use `getBytes()` instead.
`byte[]`	`getBytes()`	Get the data backing 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()`	Deprecated. Use `getLength()` instead.
`int`	`hashCode()`	Return a hash of the bytes returned from {#getBytes()}.
`void`	`readFields(java.io.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 capacity)`	Change the capacity of the backing storage.
`void`	`setSize(int size)`	Change the size of the buffer.
`java.lang.String`	`toString()`	Generate the stream of bytes as hex pairs separated by ' '.
`void`	`write(java.io.DataOutput out)`	Serialize the fields of this object to `out`.

Methods inherited from class org.apache.hadoop.io.BinaryComparable
compareTo, compareTo

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.lang.Comparable
compareTo

- Constructor Detail
  - BytesWritable
```
public BytesWritable()
```
    Create a zero-size sequence.
  - BytesWritable
```
public BytesWritable(byte[] bytes)
```
    Create a BytesWritable using the byte array as the initial value.
    
    Parameters:
    
    bytes - This array becomes the backing storage for the object.
  - BytesWritable
```
public BytesWritable(byte[] bytes,
                     int length)
```
    Create a BytesWritable using the byte array as the initial value and length as the length. Use this constructor if the array is larger than the value it represents.
    
    Parameters:
    
    bytes - This array becomes the backing storage for the object.
    
    length - The number of bytes to use from array.
- Method Detail
  - copyBytes
```
public byte[] copyBytes()
```
    Get a copy of the bytes that is exactly the length of the data. See getBytes() for faster access to the underlying array.
    
    Returns:
    
    copyBytes.
  - getBytes
```
public byte[] getBytes()
```
    Get the data backing the BytesWritable. Please use copyBytes() if you need the returned array to be precisely the length of the data.
    
    Specified by:
    
    getBytes in class BinaryComparable
    
    Returns:
    
    The data is only valid between 0 and getLength() - 1.
  - get
```
@Deprecated
public byte[] get()
```
    Deprecated.
    Use getBytes() instead.
    
    Get the data from the BytesWritable.
    
    Returns:
    
    data from the BytesWritable.
  - getLength
```
public int getLength()
```
    Get the current size of the buffer.
    
    Specified by:
    
    getLength in class BinaryComparable
    
    Returns:
    
    length.
  - getSize
```
@Deprecated
public int getSize()
```
    Deprecated.
    Use getLength() instead.
    
    Get the current size of the buffer.
    
    Returns:
    
    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.
    
    Parameters:
    
    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.
    
    Returns:
    
    The number of bytes
  - setCapacity
```
public void setCapacity(int capacity)
```
    Change the capacity of the backing storage. The data is preserved.
    
    Parameters:
    
    capacity - The new capacity in bytes.
  - set
```
public void set(BytesWritable newData)
```
    Set the BytesWritable to the contents of the given newData.
    
    Parameters:
    
    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.
    
    Parameters:
    
    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(java.io.DataInput in)
                throws java.io.IOException
```
    Description copied from interface: Writable
    
    Deserialize the fields of this object from in.
    For efficiency, implementations should attempt to re-use storage in the existing object where possible.
    
    Specified by:
    
    readFields in interface Writable
    
    Parameters:
    
    in - DataInput to deseriablize this object from.
    
    Throws:
    
    java.io.IOException - any other problem for readFields.
  - write
```
public void write(java.io.DataOutput out)
           throws java.io.IOException
```
    Description copied from interface: Writable
    
    Serialize the fields of this object to out.
    
    Specified by:
    
    write in interface Writable
    
    Parameters:
    
    out - DataOuput to serialize this object into.
    
    Throws:
    
    java.io.IOException - any other problem for write.
  - equals
```
public boolean equals(java.lang.Object right_obj)
```
    Are the two byte sequences equal?
    
    Overrides:
    
    equals in class BinaryComparable
  - hashCode
```
public int hashCode()
```
    Description copied from class: BinaryComparable
    
    Return a hash of the bytes returned from {#getBytes()}.
    
    Overrides:
    
    hashCode in class BinaryComparable
    
    See Also:
    
    WritableComparator.hashBytes(byte[],int)
  - toString
```
public java.lang.String toString()
```
    Generate the stream of bytes as hex pairs separated by ' '.
    
    Overrides:
    
    toString in class java.lang.Object

Class BytesWritable

Nested Class Summary

Constructor Summary

Method Summary

Methods inherited from class org.apache.hadoop.io.BinaryComparable

Methods inherited from class java.lang.Object

Methods inherited from interface java.lang.Comparable

Constructor Detail

BytesWritable

BytesWritable

BytesWritable

Method Detail

copyBytes

getBytes

get

getLength

getSize

setSize

getCapacity

setCapacity

set

set

readFields

write

equals

hashCode

toString