public abstract class LongBuffer extends Buffer implements Comparable<LongBuffer>
A long buffer.
This class defines four categories of operations upon long buffers:
Absolute and relative get
and put
methods that read and write single longs;
Relative bulk get
methods that transfer contiguous sequences of longs from this buffer into an array; and
Relative bulk put
methods that transfer contiguous sequences of longs from a long array or some other long buffer into this buffer; and
Methods for compacting
, duplicating
, and slicing
a long buffer.
Long buffers can be created either by allocation
, which allocates space for the buffer's content, by wrapping
an existing long array into a buffer, or by creating a view of an existing byte buffer.
Like a byte buffer, a long buffer is either direct or non-direct. A long buffer created via the wrap
methods of this class will be non-direct. A long 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 long 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.
public static LongBuffer allocate(int capacity)
Allocates a new long buffer.
The new buffer's position will be zero, its limit will be its capacity, its mark will be undefined, and each of its elements will be initialized to zero. It will have a backing array
, and its array offset
will be zero.
capacity
- The new buffer's capacity, in longsIllegalArgumentException
- If the capacity
is a negative integerpublic static LongBuffer wrap(long[] array, int offset, int length)
Wraps a long array into a buffer.
The new buffer will be backed by the given long 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 backing array
will be the given array, and its array offset
will be zero.
array
- The array that will back the new bufferoffset
- 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
.IndexOutOfBoundsException
- If the preconditions on the offset
and length
parameters do not holdpublic static LongBuffer wrap(long[] array)
Wraps a long array into a buffer.
The new buffer will be backed by the given long 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 backing array
will be the given array, and its array offset>
will be zero.
array
- The array that will back this bufferpublic abstract LongBuffer slice()
Creates a new long 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 longs 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.
public abstract LongBuffer duplicate()
Creates a new long 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.
public abstract LongBuffer asReadOnlyBuffer()
Creates a new, read-only long 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 duplicate
method.
public abstract long get()
Relative get method. Reads the long at this buffer's current position, and then increments the position.
BufferUnderflowException
- If the buffer's current position is not smaller than its limitpublic abstract LongBuffer put(long l)
Relative put method (optional operation).
Writes the given long into this buffer at the current position, and then increments the position.
l
- The long to be writtenBufferOverflowException
- If this buffer's current position is not smaller than its limitReadOnlyBufferException
- If this buffer is read-onlypublic abstract long get(int index)
Absolute get method. Reads the long at the given index.
index
- The index from which the long will be readIndexOutOfBoundsException
- If index
is negative or not smaller than the buffer's limitpublic abstract LongBuffer put(int index, long l)
Absolute put method (optional operation).
Writes the given long into this buffer at the given index.
index
- The index at which the long will be writtenl
- The long value to be writtenIndexOutOfBoundsException
- If index
is negative or not smaller than the buffer's limitReadOnlyBufferException
- If this buffer is read-onlypublic LongBuffer get(long[] dst, int offset, int length)
Relative bulk get method.
This method transfers longs from this buffer into the given destination array. If there are fewer longs remaining in the buffer than are required to satisfy the request, that is, if length
>
remaining()
, then no longs are transferred and a BufferUnderflowException
is thrown.
Otherwise, this method copies length
longs 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 longs in this buffer and it is potentially much more efficient.
dst
- The array into which longs are to be writtenoffset
- The offset within the array of the first long to be written; must be non-negative and no larger than dst.length
length
- The maximum number of longs to be written to the given array; must be non-negative and no larger than dst.length - offset
BufferUnderflowException
- If there are fewer than length
longs remaining in this bufferIndexOutOfBoundsException
- If the preconditions on the offset
and length
parameters do not holdpublic LongBuffer get(long[] dst)
Relative bulk get method.
This method transfers longs 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)
dst
- The destination arrayBufferUnderflowException
- If there are fewer than length
longs remaining in this bufferpublic LongBuffer put(LongBuffer src)
Relative bulk put method (optional operation).
This method transfers the longs remaining in the given source buffer into this buffer. If there are more longs remaining in the source buffer than in this buffer, that is, if src.remaining()
>
remaining()
, then no longs are transferred and a BufferOverflowException
is thrown.
Otherwise, this method copies n = src.remaining()
longs 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.
src
- The source buffer from which longs are to be read; must not be this bufferBufferOverflowException
- If there is insufficient space in this buffer for the remaining longs in the source bufferIllegalArgumentException
- If the source buffer is this bufferReadOnlyBufferException
- If this buffer is read-onlypublic LongBuffer put(long[] src, int offset, int length)
Relative bulk put method (optional operation).
This method transfers longs into this buffer from the given source array. If there are more longs to be copied from the array than remain in this buffer, that is, if length
>
remaining()
, then no longs are transferred and a BufferOverflowException
is thrown.
Otherwise, this method copies length
longs 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.
src
- The array from which longs are to be readoffset
- The offset within the array of the first long to be read; must be non-negative and no larger than array.length
length
- The number of longs to be read from the given array; must be non-negative and no larger than array.length - offset
BufferOverflowException
- If there is insufficient space in this bufferIndexOutOfBoundsException
- If the preconditions on the offset
and length
parameters do not holdReadOnlyBufferException
- If this buffer is read-onlypublic final LongBuffer put(long[] src)
Relative bulk put method (optional operation).
This method transfers the entire content of the given source long 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)
src
- The source arrayBufferOverflowException
- If there is insufficient space in this bufferReadOnlyBufferException
- If this buffer is read-onlypublic final boolean hasArray()
Tells whether or not this buffer is backed by an accessible long array.
If this method returns true
then the array
and arrayOffset
methods may safely be invoked.
hasArray
in class Buffer
true
if, and only if, this buffer is backed by an array and is not read-onlypublic final long[] array()
Returns the long 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 hasArray
method before invoking this method in order to ensure that this buffer has an accessible backing array.
array
in class Buffer
ReadOnlyBufferException
- If this buffer is backed by an array but is read-onlyUnsupportedOperationException
- If this buffer is not backed by an accessible arraypublic 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 hasArray
method before invoking this method in order to ensure that this buffer has an accessible backing array.
arrayOffset
in class Buffer
ReadOnlyBufferException
- If this buffer is backed by an array but is read-onlyUnsupportedOperationException
- If this buffer is not backed by an accessible arraypublic abstract LongBuffer compact()
Compacts this buffer (optional operation).
The longs between the buffer's current position and its limit, if any, are copied to the beginning of the buffer. That is, the long at index p = position()
is copied to index zero, the long at index p + 1 is copied to index one, and so forth until the long 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 longs copied, rather than to zero, so that an invocation of this method can be followed immediately by an invocation of another relative put method.
ReadOnlyBufferException
- If this buffer is read-onlypublic abstract boolean isDirect()
Tells whether or not this long buffer is direct.
public String toString()
Returns a string summarizing the state of this buffer.
public int hashCode()
Returns the current hash code of this buffer.
The hash code of a long 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.
hashCode
in class Object
Object.equals(java.lang.Object)
, System.identityHashCode(java.lang.Object)
public boolean equals(Object ob)
Tells whether or not this buffer is equal to another object.
Two long 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 long buffer is not equal to any other type of object.
equals
in class Object
ob
- The object to which this buffer is to be comparedtrue
if, and only if, this buffer is equal to the given objectObject.hashCode()
, HashMap
public int compareTo(LongBuffer that)
Compares this buffer to another.
Two long 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 long
elements are compared as if by invoking Long.compare(long,long)
.
A long buffer is not comparable to any other type of object.
compareTo
in interface Comparable<LongBuffer>
that
- the object to be compared.public abstract ByteOrder order()
Retrieves this buffer's byte order.
The byte order of a long buffer created by allocation or by wrapping an existing long
array is the native order
of the underlying hardware. The byte order of a long buffer created as a view of a byte buffer is that of the byte buffer at the moment that the view is created.
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Documentation extracted from Debian's OpenJDK Development Kit package.
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