DoubleBuffer (Java Platform SE 6)

This documentation differs from the official API. Jadeite adds extra features to the API including: variable font sizes, constructions examples, placeholders for classes and methods, and auto-generated “See Also” links. Additionally it is missing some items found in standard Javadoc documentation, including: generics type information, “Deprecated” tags and comments, “See Also” links, along with other minor differences. Please send any questions or feedback to bam@cs.cmu.edu.

Overview

Package

Class

PREV CLASS NEXT CLASS

FRAMES NO FRAMES

SUMMARY: NESTED | FIELD | CONSTR | METHOD

DETAIL: FIELD | CONSTR | METHOD

java.nio
class DoubleBuffer

java.lang.Object
  java.nio.Buffer
      java.nio.DoubleBuffer

All Implemented Interfaces:: Comparable

public abstract class DoubleBuffer
extends Buffer
implements Comparable

A double buffer.

This class defines four categories of operations upon double buffers:

Absolute and relative {@link #get() get} and {@link #put(double)put} methods that read and write single doubles;

Relative {@link #get(double[]) bulk get} methods that transfer contiguous sequences of doubles from this buffer into an array; and

Relative {@link #put(double[]) bulk put} methods that transfer contiguous sequences of doubles from a double array or some other double buffer into this buffer; and

Methods for {@link #compact compacting}, {@link #duplicateduplicating}, and {@link #sliceslicing} a double buffer.

Double buffers can be created either by {@link #allocateallocation}, which allocates space for the buffer's content, by {@link #wrap(double[])wrapping} an existing double array into a buffer, or by creating a view of an existing byte buffer.

Like a byte buffer, a double buffer is either direct or non-direct. A double buffer created via the wrap methods of this class will be non-direct. A double buffer created as a view of a byte buffer will be direct if, and only if, the byte buffer itself is direct. Whether or not a double buffer is direct may be determined by invoking the {@link #isDirect isDirect} method.


















  Methods in this class that do not otherwise have a value to return are
 specified to return the buffer upon which they are invoked.  This allows
 method invocations to be chained.




	
		Method Summary
	
	
		static DoubleBuffer
		allocate(int capacity)
			
          Allocates a new double buffer.
		
	
	
		 double[]
		array()
			
          Returns the double array that backs this
 buffer  (optional operation).
		
	
	
		 int
		arrayOffset()
			
          Returns the offset within this buffer's backing array of the first
 element of the buffer  (optional operation).
		
	
	
		abstract DoubleBuffer
		asReadOnlyBuffer()
			
          Creates a new, read-only double buffer that shares this buffer's
 content.
		
	
	
		abstract DoubleBuffer
		compact()
			
          Compacts this buffer  (optional operation).
		
	
	
		 int
		compareTo(DoubleBuffer that)
			
          Compares this buffer to another.
		
	
	
		abstract DoubleBuffer
		duplicate()
			
          Creates a new double buffer that shares this buffer's content.
		
	
	
		 boolean
		equals(Object ob)
			
          Tells whether or not this buffer is equal to another object.
		
	
	
		abstract double
		get()
			
          Relative get method.
		
	
	
		 DoubleBuffer
		get(double[] dst)
			
          Relative bulk get method.
		
	
	
		 DoubleBuffer
		get(double[] dst, int offset, int length)
			
          Relative bulk get method.
		
	
	
		abstract double
		get(int index)
			
          Absolute get method.
		
	
	
		 boolean
		hasArray()
			
          Tells whether or not this buffer is backed by an accessible double
 array.
		
	
	
		 int
		hashCode()
			
          Returns the current hash code of this buffer.
		
	
	
		abstract boolean
		isDirect()
			
          Tells whether or not this double buffer is direct.
		
	
	
		abstract ByteOrder
		order()
			
          Retrieves this buffer's byte order.
		
	
	
		abstract DoubleBuffer
		put(double d)
			
          Relative put method  (optional operation).
		
	
	
		 DoubleBuffer
		put(DoubleBuffer src)
			
          Relative bulk put method  (optional operation).
		
	
	
		 DoubleBuffer
		put(double[] src)
			
          Relative bulk put method  (optional operation).
		
	
	
		 DoubleBuffer
		put(double[] src, int offset, int length)
			
          Relative bulk put method  (optional operation).
		
	
	
		abstract DoubleBuffer
		put(int index, double d)
			
          Absolute put method  (optional operation).
		
	
	
		abstract DoubleBuffer
		slice()
			
          Creates a new double buffer whose content is a shared subsequence of
 this buffer's content.
		
	
	
		 String
		toString()
			
          Returns a string summarizing the state of this buffer.
		
	
	
		static DoubleBuffer
		wrap(double[] array)
			
          Wraps a double array into a buffer.
		
	
	
		static DoubleBuffer
		wrap(double[] array, int offset, int length)
			
          Wraps a double array into a buffer.
		
	

 



Methods inherited from class java.nio.Buffer


array, arrayOffset, capacity, clear, flip, hasArray, hasRemaining, isDirect, isReadOnly, limit, limit, mark, position, position, remaining, reset, rewind 



Methods inherited from class java.lang.Object


clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait 





Method Detail


allocate
public static DoubleBuffer allocate(int capacity)

Method Summary
`static DoubleBuffer`	`allocate(int capacity)` Allocates a new double buffer.
`double[]`	`array()` Returns the double array that backs this buffer (optional operation).
`int`	`arrayOffset()` Returns the offset within this buffer's backing array of the first element of the buffer (optional operation).
`abstract DoubleBuffer`	`asReadOnlyBuffer()` Creates a new, read-only double buffer that shares this buffer's content.
`abstract DoubleBuffer`	`compact()` Compacts this buffer (optional operation).
`int`	`compareTo(DoubleBuffer that)` Compares this buffer to another.
`abstract DoubleBuffer`	`duplicate()` Creates a new double buffer that shares this buffer's content.
`boolean`	`equals(Object ob)` Tells whether or not this buffer is equal to another object.
`abstract double`	`get()` Relative get method.
`DoubleBuffer`	`get(double[] dst)` Relative bulk get method.
`DoubleBuffer`	`get(double[] dst, int offset, int length)` Relative bulk get method.
`abstract double`	`get(int index)` Absolute get method.
`boolean`	`hasArray()` Tells whether or not this buffer is backed by an accessible double array.
`int`	`hashCode()` Returns the current hash code of this buffer.
`abstract boolean`	`isDirect()` Tells whether or not this double buffer is direct.
`abstract ByteOrder`	`order()` Retrieves this buffer's byte order.
`abstract DoubleBuffer`	`put(double d)` Relative put method (optional operation).
`DoubleBuffer`	`put(DoubleBuffer src)` Relative bulk put method (optional operation).
`DoubleBuffer`	`put(double[] src)` Relative bulk put method (optional operation).
`DoubleBuffer`	`put(double[] src, int offset, int length)` Relative bulk put method (optional operation).
`abstract DoubleBuffer`	`put(int index, double d)` Absolute put method (optional operation).
`abstract DoubleBuffer`	`slice()` Creates a new double buffer whose content is a shared subsequence of this buffer's content.
`String`	`toString()` Returns a string summarizing the state of this buffer.
`static DoubleBuffer`	`wrap(double[] array)` Wraps a double array into a buffer.
`static DoubleBuffer`	`wrap(double[] array, int offset, int length)` Wraps a double array into a buffer.

Methods inherited from class java.nio.Buffer
`array, arrayOffset, capacity, clear, flip, hasArray, hasRemaining, isDirect, isReadOnly, limit, limit, mark, position, position, remaining, reset, rewind`

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`


Allocates a new double buffer.

The new buffer's position will be zero, its limit will be its capacity, and its mark will be undefined. It will have a {@link #arraybacking array}, and its {@link #arrayOffset array offset} will be zero.

Parameters:: capacity - The new buffer's capacity, in doubles
Returns:: The new double buffer



array
public final double[] array()


Returns the double array that backs this
 buffer  (optional operation).

  Modifications to this buffer's content will cause the returned
 array's content to be modified, and vice versa.

 
 Invoke the {@link #hasArray hasArray} method before invoking this
 method in order to ensure that this buffer has an accessible backing
 array.  


Overrides:
array in class Buffer
Returns:
The array that backs this buffer



arrayOffset
public final int arrayOffset()


Returns the offset within this buffer's backing array of the first
 element of the buffer  (optional operation).

  If this buffer is backed by an array then buffer position p
 corresponds to array index p + arrayOffset().

 
 Invoke the {@link #hasArray hasArray} method before invoking this
 method in order to ensure that this buffer has an accessible backing
 array.  


Overrides:
arrayOffset in class Buffer
Returns:
The offset within this buffer's array
          of the first element of the buffer



asReadOnlyBuffer
public abstract DoubleBuffer asReadOnlyBuffer()


Creates a new, read-only double buffer that shares this buffer's
 content.

  The content of the new buffer will be that of this buffer.  Changes
 to this buffer's content will be visible in the new buffer; the new
 buffer itself, however, will be read-only and will not allow the shared
 content to be modified.  The two buffers' position, limit, and mark
 values will be independent.

 
 The new buffer's capacity, limit, position, and mark values will be
 identical to those of this buffer.

 
 If this buffer is itself read-only then this method behaves in
 exactly the same way as the {@link #duplicate duplicate} method.  


Returns:
The new, read-only double buffer



compact
public abstract DoubleBuffer compact()


Compacts this buffer  (optional operation).

  The doubles between the buffer's current position and its limit,
 if any, are copied to the beginning of the buffer.  That is, the
 double at index p = position() is copied
 to index zero, the double at index p + 1 is copied
 to index one, and so forth until the double at index
 limit() - 1 is copied to index
 n = limit() - 1 - p.
 The buffer's position is then set to n+1 and its limit is set to
 its capacity.  The mark, if defined, is discarded.

 
 The buffer's position is set to the number of doubles copied,
 rather than to zero, so that an invocation of this method can be
 followed immediately by an invocation of another relative put
 method. 


Returns:
This buffer



compareTo
public int compareTo(DoubleBuffer that)


Compares this buffer to another.

  Two double buffers are compared by comparing their sequences of
 remaining elements lexicographically, without regard to the starting
 position of each sequence within its corresponding buffer.

 
 A double buffer is not comparable to any other type of object.


Parameters:
that
Returns:
A negative integer, zero, or a positive integer as this buffer
		is less than, equal to, or greater than the given buffer



duplicate
public abstract DoubleBuffer duplicate()


Creates a new double buffer that shares this buffer's content.

  The content of the new buffer will be that of this buffer.  Changes
 to this buffer's content will be visible in the new buffer, and vice
 versa; the two buffers' position, limit, and mark values will be
 independent.

 
 The new buffer's capacity, limit, position, and mark values will be
 identical to those of this buffer.  The new buffer will be direct if,
 and only if, this buffer is direct, and it will be read-only if, and
 only if, this buffer is read-only.  


Returns:
The new double buffer



equals
public boolean equals(Object ob)


Tells whether or not this buffer is equal to another object.

  Two double buffers are equal if, and only if,

 


    They have the same element type,  

    They have the same number of remaining elements, and
   

    The two sequences of remaining elements, considered
   independently of their starting positions, are pointwise equal.
   

 

  A double buffer is not equal to any other type of object.  


Overrides:
equals in class Object
Parameters:
ob - The object to which this buffer is to be compared
Returns:
true if, and only if, this buffer is equal to the
           given object



get
public abstract double get()


Relative get method.  Reads the double at this buffer's
 current position, and then increments the position. 


Returns:
The double at the buffer's current position



get
public DoubleBuffer get(double[] dst)


Relative bulk get method.

  This method transfers doubles from this buffer into the given
 destination array.  An invocation of this method of the form
 src.get(a) behaves in exactly the same way as the invocation

 
     src.get(a, 0, a.length) 


Parameters:
dst
Returns:
This buffer



get
public DoubleBuffer get(double[] dst,
                        int offset,
                        int length)


Relative bulk get method.

  This method transfers doubles from this buffer into the given
 destination array.  If there are fewer doubles remaining in the
 buffer than are required to satisfy the request, that is, if
 length > remaining(), then no
 doubles are transferred and a {@link BufferUnderflowException} is
 thrown.

 
 Otherwise, this method copies length doubles from this
 buffer into the given array, starting at the current position of this
 buffer and at the given offset in the array.  The position of this
 buffer is then incremented by length.

 
 In other words, an invocation of this method of the form
 src.get(dst, off, len) has exactly the same effect as
 the loop

 
     for (int i = off; i < off + len; i++)
         dst[i] = src.get(); 

 except that it first checks that there are sufficient doubles in
 this buffer and it is potentially much more efficient. 


Parameters:
dst - The array into which doubles are to be written
offset - The offset within the array of the first double to be
         written; must be non-negative and no larger than
         dst.length
length - The maximum number of doubles to be written to the given
         array; must be non-negative and no larger than
         dst.length - offset
Returns:
This buffer



get
public abstract double get(int index)


Absolute get method.  Reads the double at the given
 index. 


Parameters:
index - The index from which the double will be read
Returns:
The double at the given index



hasArray
public final boolean hasArray()


Tells whether or not this buffer is backed by an accessible double
 array.

  If this method returns true then the {@link #array() array}
 and {@link #arrayOffset() arrayOffset} methods may safely be invoked.
 


Overrides:
hasArray in class Buffer
Returns:
true if, and only if, this buffer
          is backed by an array and is not read-only



hashCode
public int hashCode()


Returns the current hash code of this buffer.

  The hash code of a double buffer depends only upon its remaining
 elements; that is, upon the elements from position() up to, and
 including, the element at limit() - 1.

 
 Because buffer hash codes are content-dependent, it is inadvisable
 to use buffers as keys in hash maps or similar data structures unless it
 is known that their contents will not change.  


Overrides:
hashCode in class Object
Returns:
The current hash code of this buffer



isDirect
public abstract boolean isDirect()


Tells whether or not this double buffer is direct. 


Overrides:
isDirect in class Buffer
Returns:
true if, and only if, this buffer is direct



order
public abstract ByteOrder order()


Retrieves this buffer's byte order.

The byte order of a double buffer created by allocation or by wrapping an existing double array is the {@link ByteOrder#nativeOrdernative order} of the underlying hardware. The byte order of a double buffer created as a view of a byte buffer is that of the byte buffer at the moment that the view is created.

Returns:: This buffer's byte order



put
public abstract DoubleBuffer put(double d)


Relative put method  (optional operation).
 
  Writes the given double into this buffer at the current
 position, and then increments the position. 


Parameters:
d - The double to be written
Returns:
This buffer



put
public DoubleBuffer put(DoubleBuffer src)


Relative bulk put method  (optional operation).

  This method transfers the doubles remaining in the given source
 buffer into this buffer.  If there are more doubles remaining in the
 source buffer than in this buffer, that is, if
 src.remaining() > remaining(),
 then no doubles are transferred and a {@link
 BufferOverflowException} is thrown.

 
 Otherwise, this method copies
 n = src.remaining() doubles from the given
 buffer into this buffer, starting at each buffer's current position.
 The positions of both buffers are then incremented by n.

 
 In other words, an invocation of this method of the form
 dst.put(src) has exactly the same effect as the loop

 
     while (src.hasRemaining())
         dst.put(src.get()); 

 except that it first checks that there is sufficient space in this
 buffer and it is potentially much more efficient. 


Parameters:
src - The source buffer from which doubles are to be read;
         must not be this buffer
Returns:
This buffer



put
public final DoubleBuffer put(double[] src)


Relative bulk put method  (optional operation).

  This method transfers the entire content of the given source
 double array into this buffer.  An invocation of this method of the
 form dst.put(a) behaves in exactly the same way as the
 invocation

 
     dst.put(a, 0, a.length) 


Parameters:
src
Returns:
This buffer



put
public DoubleBuffer put(double[] src,
                        int offset,
                        int length)


Relative bulk put method  (optional operation).

  This method transfers doubles into this buffer from the given
 source array.  If there are more doubles to be copied from the array
 than remain in this buffer, that is, if
 length > remaining(), then no
 doubles are transferred and a {@link BufferOverflowException} is
 thrown.

 
 Otherwise, this method copies length doubles from the
 given array into this buffer, starting at the given offset in the array
 and at the current position of this buffer.  The position of this buffer
 is then incremented by length.

 
 In other words, an invocation of this method of the form
 dst.put(src, off, len) has exactly the same effect as
 the loop

 
     for (int i = off; i < off + len; i++)
         dst.put(a[i]); 

 except that it first checks that there is sufficient space in this
 buffer and it is potentially much more efficient. 


Parameters:
src - The array from which doubles are to be read
offset - The offset within the array of the first double to be read;
         must be non-negative and no larger than array.length
length - The number of doubles to be read from the given array;
         must be non-negative and no larger than
         array.length - offset
Returns:
This buffer



put
public abstract DoubleBuffer put(int index,
                                 double d)


Absolute put method  (optional operation).
 
  Writes the given double into this buffer at the given
 index. 


Parameters:
index - The index at which the double will be written
d - The double value to be written
Returns:
This buffer



slice
public abstract DoubleBuffer slice()


Creates a new double buffer whose content is a shared subsequence of
 this buffer's content.

  The content of the new buffer will start at this buffer's current
 position.  Changes to this buffer's content will be visible in the new
 buffer, and vice versa; the two buffers' position, limit, and mark
 values will be independent.

 
 The new buffer's position will be zero, its capacity and its limit
 will be the number of doubles remaining in this buffer, and its mark
 will be undefined.  The new buffer will be direct if, and only if, this
 buffer is direct, and it will be read-only if, and only if, this buffer
 is read-only.  


Returns:
The new double buffer



toString
public String toString()


Returns a string summarizing the state of this buffer.  


Overrides:
toString in class Object
Returns:
A summary string



wrap
public static DoubleBuffer wrap(double[] array)


Wraps a double array into a buffer.

The new buffer will be backed by the given double array; that is, modifications to the buffer will cause the array to be modified and vice versa. The new buffer's capacity and limit will be array.length, its position will be zero, and its mark will be undefined. Its {@link #arraybacking array} will be the given array, and its {@link #arrayOffsetarray offset} will be zero.

Parameters:: array - The array that will back this buffer
Returns:: The new double buffer



wrap
public static DoubleBuffer wrap(double[] array,
                                int offset,
                                int length)


Wraps a double array into a buffer.

The new buffer will be backed by the given double array; that is, modifications to the buffer will cause the array to be modified and vice versa. The new buffer's capacity will be array.length, its position will be offset, its limit will be offset + length, and its mark will be undefined. Its {@link #arraybacking array} will be the given array, and its {@link #arrayOffsetarray offset} will be zero.

Parameters:: array - The array that will back the new buffer; offset - The offset of the subarray to be used; must be non-negative and no larger than array.length. The new buffer's position will be set to this value.; length - The length of the subarray to be used; must be non-negative and no larger than array.length - offset. The new buffer's limit will be set to offset + length.
Returns:: The new double buffer






	
	


Overview 
Package 
 Class 


 PREV CLASS 
 NEXT CLASS


FRAMES 
 NO FRAMES 

	
	
SUMMARY: NESTED | FIELD | CONSTR | METHOD 

DETAIL: FIELD | CONSTR | METHOD 






	
	This documentation differs from the official API.

	Jadeite adds extra features to the API including:
		variable font sizes,
		constructions examples,
		placeholders for classes and methods, and auto-generated “See Also” links.

	Additionally it is missing some items found in standard Javadoc documentation, including:
		generics type information,
		“Deprecated” tags and comments,
		“See Also” links,
		along with other minor differences.

	Please send any questions or feedback to bam@cs.cmu.edu.
This page displays the Jadeite version of the documention, which is derived from the offical documentation that contains this copyright notice:Copyright 2008 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.
The official Sun™ documentation can be found here at http://java.sun.com/javase/6/docs/api/.

java.nioclass DoubleBuffer

allocate

array

arrayOffset

asReadOnlyBuffer

compact

compareTo

duplicate

equals

get

get

get

get

hasArray

hashCode

isDirect

order

put

put

put

put

put

slice

toString

wrap

wrap

java.nio
class DoubleBuffer