- All Implemented Interfaces:
- Comparable<DoubleBuffer>
This class defines four categories of operations upon double buffers:
- Absolute and relative - getand- putmethods that read and write single doubles;
- Absolute and relative - bulk getmethods that transfer contiguous sequences of doubles from this buffer into an array;
- Absolute and relative - bulk putmethods that transfer contiguous sequences of doubles from a double array or some other double buffer into this buffer;
- A method for - compactinga double buffer.
 Double buffers can be created either by allocation, which allocates space for the buffer's
 content, by 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 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.
- Since:
- 1.4
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Method SummaryModifier and TypeMethodDescriptionstatic DoubleBufferallocate(int capacity) Allocates a new double buffer.final double[]array()Returns the double array that backs this buffer (optional operation).final intReturns the offset within this buffer's backing array of the first element of the buffer (optional operation).abstract DoubleBufferCreates a new, read-only double buffer that shares this buffer's content.final DoubleBufferclear()Clears this buffer.abstract DoubleBuffercompact()Compacts this buffer (optional operation).intcompareTo(DoubleBuffer that) Compares this buffer to another.abstract DoubleBufferCreates a new double buffer that shares this buffer's content.booleanTells whether or not this buffer is equal to another object.final DoubleBufferflip()Flips this buffer.abstract doubleget()Relative get method.get(double[] dst) Relative bulk get method.get(double[] dst, int offset, int length) Relative bulk get method.abstract doubleget(int index) Absolute get method.get(int index, double[] dst) Absolute bulk get method.get(int index, double[] dst, int offset, int length) Absolute bulk get method.final booleanhasArray()Tells whether or not this buffer is backed by an accessible double array.inthashCode()Returns the current hash code of this buffer.abstract booleanisDirect()Tells whether or not this double buffer is direct.final DoubleBufferlimit(int newLimit) Sets this buffer's limit.final DoubleBuffermark()Sets this buffer's mark at its position.intmismatch(DoubleBuffer that) Finds and returns the relative index of the first mismatch between this buffer and a given buffer.abstract ByteOrderorder()Retrieves this buffer's byte order.final DoubleBufferposition(int newPosition) Sets this buffer's position.abstract DoubleBufferput(double d) Relative put method (optional operation).final DoubleBufferput(double[] src) Relative bulk put method (optional operation).put(double[] src, int offset, int length) Relative bulk put method (optional operation).abstract DoubleBufferput(int index, double d) Absolute put method (optional operation).put(int index, double[] src) Absolute bulk put method (optional operation).put(int index, double[] src, int offset, int length) Absolute bulk put method (optional operation).put(int index, DoubleBuffer src, int offset, int length) Absolute bulk put method (optional operation).put(DoubleBuffer src) Relative bulk put method (optional operation).final DoubleBufferreset()Resets this buffer's position to the previously-marked position.final DoubleBufferrewind()Rewinds this buffer.abstract DoubleBufferslice()Creates a new double buffer whose content is a shared subsequence of this buffer's content.abstract DoubleBufferslice(int index, int length) Creates a new double buffer whose content is a shared subsequence of this buffer's content.toString()Returns a string summarizing the state of this buffer.static DoubleBufferwrap(double[] array) Wraps a double array into a buffer.static DoubleBufferwrap(double[] array, int offset, int length) Wraps a double array into a buffer.Methods declared in class java.nio.Buffercapacity, hasRemaining, isReadOnly, limit, position, remaining
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Method Details- 
allocateAllocates a new double buffer.The new buffer's position will be zero, its limit will be its capacity, its mark will be undefined, each of its elements will be initialized to zero, and its byte order will be the native orderof the underlying hardware. It will have abacking array, and itsarray offsetwill be zero.- Parameters:
- capacity- The new buffer's capacity, in doubles
- Returns:
- The new double buffer
- Throws:
- IllegalArgumentException- If the- capacityis a negative integer
 
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wrapWraps 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 beoffset, its limit will beoffset + length, its mark will be undefined, and its byte order will be thenative orderof the underlying hardware. Itsbacking arraywill be the given array, and itsarray offsetwill 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
- Throws:
- IndexOutOfBoundsException- If the preconditions on the- offsetand- lengthparameters do not hold
 
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wrapWraps 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, its mark will be undefined, and its byte order will be thenative orderof the underlying hardware. Itsbacking arraywill be the given array, and itsarray offsetwill be zero.- Parameters:
- array- The array that will back this buffer
- Returns:
- The new double buffer
 
- 
sliceCreates 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, its mark will be undefined, and its byte order will be identical to that 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. 
- 
sliceCreates a new double buffer whose content is a shared subsequence of this buffer's content.The content of the new buffer will start at position indexin this buffer, and will containlengthelements. 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 length, its mark will be undefined, and its byte order will be identical to that 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.- Specified by:
- slicein class- Buffer
- Parameters:
- index- The position in this buffer at which the content of the new buffer will start; must be non-negative and no larger than- limit()
- length- The number of elements the new buffer will contain; must be non-negative and no larger than- limit() - index
- Returns:
- The new buffer
- Throws:
- IndexOutOfBoundsException- If- indexis negative or greater than- limit(),- lengthis negative, or- length > limit() - index
- Since:
- 13
 
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duplicateCreates 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, mark values, and byte order 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. 
- 
asReadOnlyBufferCreates 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, mark values, and byte order 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 duplicatemethod.- Returns:
- The new, read-only double buffer
 
- 
getpublic 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
- Throws:
- BufferUnderflowException- If the buffer's current position is not smaller than its limit
 
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putRelative 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
- Throws:
- BufferOverflowException- If this buffer's current position is not smaller than its limit
- ReadOnlyBufferException- If this buffer is read-only
 
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getpublic 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
- Throws:
- IndexOutOfBoundsException- If- indexis negative or not smaller than the buffer's limit
 
- 
putAbsolute 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
- Throws:
- IndexOutOfBoundsException- If- indexis negative or not smaller than the buffer's limit
- ReadOnlyBufferException- If this buffer is read-only
 
- 
getRelative 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 aBufferUnderflowExceptionis thrown.Otherwise, this method copies lengthdoubles 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 bylength.In other words, an invocation of this method of the form src.get(dst, off, len)has exactly the same effect as the loop
 except that it first checks that there are sufficient doubles in this buffer and it is potentially much more efficient.for (int i = off; i < off + len; i++) dst[i] = src.get();- 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
- Throws:
- BufferUnderflowException- If there are fewer than- lengthdoubles remaining in this buffer
- IndexOutOfBoundsException- If the preconditions on the- offsetand- lengthparameters do not hold
 
- 
getRelative 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 invocationsrc.get(a, 0, a.length)- Parameters:
- dst- The destination array
- Returns:
- This buffer
- Throws:
- BufferUnderflowException- If there are fewer than- lengthdoubles remaining in this buffer
 
- 
getAbsolute bulk get method.This method transfers lengthdoubles from this buffer into the given array, starting at the given index in this buffer and at the given offset in the array. The position of this buffer is unchanged.An invocation of this method of the form src.get(index, dst, offset, length)has exactly the same effect as the following loop except that it first checks the consistency of the supplied parameters and it is potentially much more efficient:for (int i = offset, j = index; i < offset + length; i++, j++) dst[i] = src.get(j);- Parameters:
- index- The index in this buffer from which the first double will be read; must be non-negative and less than- limit()
- dst- The destination array
- offset- The offset within the array of the first double to be written; must be non-negative and less than- dst.length
- length- The number of doubles to be written to the given array; must be non-negative and no larger than the smaller of- limit() - indexand- dst.length - offset
- Returns:
- This buffer
- Throws:
- IndexOutOfBoundsException- If the preconditions on the- index,- offset, and- lengthparameters do not hold
- Since:
- 13
 
- 
getAbsolute bulk get method.This method transfers doubles from this buffer into the given destination array. The position of this buffer is unchanged. An invocation of this method of the form src.get(index, dst)behaves in exactly the same way as the invocation:src.get(index, dst, 0, dst.length)- Parameters:
- index- The index in this buffer from which the first double will be read; must be non-negative and less than- limit()
- dst- The destination array
- Returns:
- This buffer
- Throws:
- IndexOutOfBoundsException- If- indexis negative, not smaller than- limit(), or- limit() - index < dst.length
- Since:
- 13
 
- 
putRelative 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 aBufferOverflowExceptionis 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 loopwhile (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. If this buffer and the source buffer share the same backing array or memory, then the result will be as if the source elements were first copied to an intermediate location before being written into this buffer.- Parameters:
- src- The source buffer from which doubles are to be read; must not be this buffer
- Returns:
- This buffer
- Throws:
- BufferOverflowException- If there is insufficient space in this buffer for the remaining doubles in the source buffer
- IllegalArgumentException- If the source buffer is this buffer
- ReadOnlyBufferException- If this buffer is read-only
 
- 
putAbsolute bulk put method (optional operation).This method transfers lengthdoubles into this buffer from the given source buffer, starting at the givenoffsetin the source buffer and the givenindexin this buffer. The positions of both buffers are unchanged.In other words, an invocation of this method of the form dst.put(index, src, offset, length)has exactly the same effect as the loop
 except that it first checks the consistency of the supplied parameters and it is potentially much more efficient. If this buffer and the source buffer share the same backing array or memory, then the result will be as if the source elements were first copied to an intermediate location before being written into this buffer.for (int i = offset, j = index; i < offset + length; i++, j++) dst.put(j, src.get(i));- Parameters:
- index- The index in this buffer at which the first double will be written; must be non-negative and less than- limit()
- src- The buffer from which doubles are to be read
- offset- The index within the source buffer of the first double to be read; must be non-negative and less than- src.limit()
- length- The number of doubles to be read from the given buffer; must be non-negative and no larger than the smaller of- limit() - indexand- src.limit() - offset
- Returns:
- This buffer
- Throws:
- IndexOutOfBoundsException- If the preconditions on the- index,- offset, and- lengthparameters do not hold
- ReadOnlyBufferException- If this buffer is read-only
- Since:
- 16
 
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putRelative 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 aBufferOverflowExceptionis thrown.Otherwise, this method copies lengthdoubles 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 bylength.In other words, an invocation of this method of the form dst.put(src, off, len)has exactly the same effect as the loop
 except that it first checks that there is sufficient space in this buffer and it is potentially much more efficient.for (int i = off; i < off + len; i++) dst.put(src[i]);- 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- src.length
- length- The number of doubles to be read from the given array; must be non-negative and no larger than- src.length - offset
- Returns:
- This buffer
- Throws:
- BufferOverflowException- If there is insufficient space in this buffer
- IndexOutOfBoundsException- If the preconditions on the- offsetand- lengthparameters do not hold
- ReadOnlyBufferException- If this buffer is read-only
 
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putRelative 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 invocationdst.put(a, 0, a.length)- Parameters:
- src- The source array
- Returns:
- This buffer
- Throws:
- BufferOverflowException- If there is insufficient space in this buffer
- ReadOnlyBufferException- If this buffer is read-only
 
- 
putAbsolute bulk put method (optional operation).This method transfers lengthdoubles from the given array, starting at the given offset in the array and at the given index in this buffer. The position of this buffer is unchanged.An invocation of this method of the form dst.put(index, src, offset, length)has exactly the same effect as the following loop except that it first checks the consistency of the supplied parameters and it is potentially much more efficient:for (int i = offset, j = index; i < offset + length; i++, j++) dst.put(j, src[i]);- Parameters:
- index- The index in this buffer at which the first double will be written; must be non-negative and less than- limit()
- 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 less than- src.length
- length- The number of doubles to be read from the given array; must be non-negative and no larger than the smaller of- limit() - indexand- src.length - offset
- Returns:
- This buffer
- Throws:
- IndexOutOfBoundsException- If the preconditions on the- index,- offset, and- lengthparameters do not hold
- ReadOnlyBufferException- If this buffer is read-only
- Since:
- 13
 
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putAbsolute bulk put method (optional operation).This method copies doubles into this buffer from the given source array. The position of this buffer is unchanged. An invocation of this method of the form dst.put(index, src)behaves in exactly the same way as the invocation:dst.put(index, src, 0, src.length);- Parameters:
- index- The index in this buffer at which the first double will be written; must be non-negative and less than- limit()
- src- The array from which doubles are to be read
- Returns:
- This buffer
- Throws:
- IndexOutOfBoundsException- If- indexis negative, not smaller than- limit(), or- limit() - index < src.length
- ReadOnlyBufferException- If this buffer is read-only
- Since:
- 13
 
- 
hasArraypublic final boolean hasArray()Tells whether or not this buffer is backed by an accessible double array.If this method returns truethen thearrayandarrayOffsetmethods may safely be invoked.
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arraypublic 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 hasArraymethod before invoking this method in order to ensure that this buffer has an accessible backing array.- Specified by:
- arrayin class- Buffer
- Returns:
- The array that backs this buffer
- Throws:
- ReadOnlyBufferException- If this buffer is backed by an array but is read-only
- UnsupportedOperationException- If this buffer is not backed by an accessible array
 
- 
arrayOffsetpublic 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 hasArraymethod before invoking this method in order to ensure that this buffer has an accessible backing array.- Specified by:
- arrayOffsetin class- Buffer
- Returns:
- The offset within this buffer's array of the first element of the buffer
- Throws:
- ReadOnlyBufferException- If this buffer is backed by an array but is read-only
- UnsupportedOperationException- If this buffer is not backed by an accessible array
 
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positionSets this buffer's position. If the mark is defined and larger than the new position then it is discarded.
- 
limitSets this buffer's limit. If the position is larger than the new limit then it is set to the new limit. If the mark is defined and larger than the new limit then it is discarded.
- 
markSets this buffer's mark at its position.
- 
resetResets this buffer's position to the previously-marked position.Invoking this method neither changes nor discards the mark's value. 
- 
clearClears this buffer. The position is set to zero, the limit is set to the capacity, and the mark is discarded.Invoke this method before using a sequence of channel-read or put operations to fill this buffer. For example: buf.clear(); // Prepare buffer for reading in.read(buf); // Read data This method does not actually erase the data in the buffer, but it is named as if it did because it will most often be used in situations in which that might as well be the case. 
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flipFlips this buffer. The limit is set to the current position and then the position is set to zero. If the mark is defined then it is discarded.After a sequence of channel-read or put operations, invoke this method to prepare for a sequence of channel-write or relative get operations. For example: buf.put(magic); // Prepend header in.read(buf); // Read data into rest of buffer buf.flip(); // Flip buffer out.write(buf); // Write header + data to channel This method is often used in conjunction with the compactmethod when transferring data from one place to another.
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rewindRewinds this buffer. The position is set to zero and the mark is discarded.Invoke this method before a sequence of channel-write or get operations, assuming that the limit has already been set appropriately. For example: out.write(buf); // Write remaining data buf.rewind(); // Rewind buffer buf.get(array); // Copy data into array 
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compactCompacts 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 indexlimit()- 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
- Throws:
- ReadOnlyBufferException- If this buffer is read-only
 
- 
isDirectpublic abstract boolean isDirect()Tells whether or not this double buffer is direct.
- 
toStringReturns a string summarizing the state of this buffer.
- 
hashCodepublic 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 atlimit()-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. 
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equalsTells 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. This method considers two double elements - aand- bto be equal if- (a == b) || (Double.isNaN(a) && Double.isNaN(b)). The values- -0.0and- +0.0are considered to be equal, unlike- Double.equals(Object).
 A double buffer is not equal to any other type of object. 
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compareToCompares 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. Pairs of doubleelements are compared as if by invokingDouble.compare(double,double), except that-0.0and0.0are considered to be equal.Double.NaNis considered by this method to be equal to itself and greater than all otherdoublevalues (includingDouble.POSITIVE_INFINITY).A double buffer is not comparable to any other type of object. - Specified by:
- compareToin interface- Comparable<DoubleBuffer>
- Parameters:
- that- the object to be compared.
- Returns:
- A negative integer, zero, or a positive integer as this buffer is less than, equal to, or greater than the given buffer
 
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mismatchFinds and returns the relative index of the first mismatch between this buffer and a given buffer. The index is relative to thepositionof each buffer and will be in the range of 0 (inclusive) up to the smaller of theremainingelements in each buffer (exclusive).If the two buffers share a common prefix then the returned index is the length of the common prefix and it follows that there is a mismatch between the two buffers at that index within the respective buffers. If one buffer is a proper prefix of the other then the returned index is the smaller of the remaining elements in each buffer, and it follows that the index is only valid for the buffer with the larger number of remaining elements. Otherwise, there is no mismatch. - Parameters:
- that- The byte buffer to be tested for a mismatch with this buffer
- Returns:
- The relative index of the first mismatch between this and the given buffer, otherwise -1 if no mismatch.
- Since:
- 11
 
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orderRetrieves this buffer's byte order.The byte order of a double buffer created by allocation or by wrapping an existing doublearray is thenative orderof 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
 
 
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