ByteBuffer
public
abstract
class
ByteBuffer
extends Buffer
implements
Comparable<ByteBuffer>
java.lang.Object | ||
↳ | java.nio.Buffer | |
↳ | java.nio.ByteBuffer |
A byte buffer.
This class defines six categories of operations upon byte buffers:
Absolute and relative
get
andput
methods that read and write single bytes;Absolute and relative
bulk get
methods that transfer contiguous sequences of bytes from this buffer into an array;Absolute and relative
bulk put
methods that transfer contiguous sequences of bytes from a byte array or some other byte buffer into this buffer;Absolute and relative
get
andput
methods that read and write values of other primitive types, translating them to and from sequences of bytes in a particular byte order;Methods for creating view buffers, which allow a byte buffer to be viewed as a buffer containing values of some other primitive type; and
A method for
compacting
a byte buffer.
Byte buffers can be created either by allocation
, which allocates space for the buffer's
content, or by wrapping
an
existing byte array {#if[char]?or string} into a buffer.
Direct vs. non-direct buffers
A byte buffer is either direct or non-direct. Given a direct byte buffer, the Java virtual machine will make a best effort to perform native I/O operations directly upon it. That is, it will attempt to avoid copying the buffer's content to (or from) an intermediate buffer before (or after) each invocation of one of the underlying operating system's native I/O operations.
A direct byte buffer may be created by invoking the allocateDirect
factory method of this class. The
buffers returned by this method typically have somewhat higher allocation
and deallocation costs than non-direct buffers. The contents of direct
buffers may reside outside of the normal garbage-collected heap, and so
their impact upon the memory footprint of an application might not be
obvious. It is therefore recommended that direct buffers be allocated
primarily for large, long-lived buffers that are subject to the underlying
system's native I/O operations. In general it is best to allocate direct
buffers only when they yield a measurable gain in program performance.
A direct byte buffer may also be created by mapping
a region of a file
directly into memory. An implementation of the Java platform may optionally
support the creation of direct byte buffers from native code via JNI. If an
instance of one of these kinds of buffers refers to an inaccessible region
of memory then an attempt to access that region will not change the buffer's
content and will cause an unspecified exception to be thrown either at the
time of the access or at some later time.
Whether a byte buffer is direct or non-direct may be determined by
invoking its isDirect
method. This method is provided so
that explicit buffer management can be done in performance-critical code.
Access to binary data
This class defines methods for reading and writing values of all other
primitive types, except boolean
. Primitive values are translated
to (or from) sequences of bytes according to the buffer's current byte
order, which may be retrieved and modified via the order
methods. Specific byte orders are represented by instances of the ByteOrder
class. The initial order of a byte buffer is always BIG_ENDIAN
.
For access to heterogeneous binary data, that is, sequences of values of different types, this class defines a family of absolute and relative get and put methods for each type. For 32-bit floating-point values, for example, this class defines:
floatgetFloat()
floatgetFloat(int index)
voidputFloat(float f)
voidputFloat(int index, float f)
Corresponding methods are defined for the types char,
short, int, long
, and double
. The index
parameters of the absolute get and put methods are in terms of
bytes rather than of the type being read or written.
For access to homogeneous binary data, that is, sequences of values of
the same type, this class defines methods that can create views of a
given byte buffer. A view buffer is simply another buffer whose
content is backed by the byte buffer. Changes to the byte buffer's content
will be visible in the view buffer, and vice versa; the two buffers'
position, limit, and mark values are independent. The asFloatBuffer
method, for example, creates an instance of
the FloatBuffer
class that is backed by the byte buffer upon which
the method is invoked. Corresponding view-creation methods are defined for
the types char, short, int, long
, and double
.
View buffers have three important advantages over the families of type-specific get and put methods described above:
A view buffer is indexed not in terms of bytes but rather in terms of the type-specific size of its values;
A view buffer provides relative bulk get and put methods that can transfer contiguous sequences of values between a buffer and an array or some other buffer of the same type; and
A view buffer is potentially much more efficient because it will be direct if, and only if, its backing byte buffer is direct.
The byte order of a view buffer is fixed to be that of its byte buffer at the time that the view is created.
Invocation chaining
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. The sequence of statements
can, for example, be replaced by the single statement bb.putInt(0xCAFEBABE); bb.putShort(3); bb.putShort(45);
bb.putInt(0xCAFEBABE).putShort(3).putShort(45);
Summary
Public methods | |
---|---|
final
ByteBuffer
|
alignedSlice(int unitSize)
Creates a new byte buffer whose content is a shared and aligned subsequence of this buffer's content. |
final
int
|
alignmentOffset(int index, int unitSize)
Returns the memory address, pointing to the byte at the given index, modulo the given unit size. |
static
ByteBuffer
|
allocate(int capacity)
Allocates a new byte buffer. |
static
ByteBuffer
|
allocateDirect(int capacity)
Allocates a new direct byte buffer. |
final
byte[]
|
array()
Returns the byte array that backs this buffer (optional operation). |
final
int
|
arrayOffset()
Returns the offset within this buffer's backing array of the first element of the buffer (optional operation). |
abstract
CharBuffer
|
asCharBuffer()
Creates a view of this byte buffer as a char buffer. |
abstract
DoubleBuffer
|
asDoubleBuffer()
Creates a view of this byte buffer as a double buffer. |
abstract
FloatBuffer
|
asFloatBuffer()
Creates a view of this byte buffer as a float buffer. |
abstract
IntBuffer
|
asIntBuffer()
Creates a view of this byte buffer as an int buffer. |
abstract
LongBuffer
|
asLongBuffer()
Creates a view of this byte buffer as a long buffer. |
abstract
ByteBuffer
|
asReadOnlyBuffer()
Creates a new, read-only byte buffer that shares this buffer's content. |
abstract
ShortBuffer
|
asShortBuffer()
Creates a view of this byte buffer as a short buffer. |
Buffer
|
clear()
Clears this buffer. |
abstract
ByteBuffer
|
compact()
Compacts this buffer (optional operation). |
int
|
compareTo(ByteBuffer that)
Compares this buffer to another. |
abstract
ByteBuffer
|
duplicate()
Creates a new byte buffer that shares this buffer's content. |
boolean
|
equals(Object ob)
Tells whether or not this buffer is equal to another object. |
Buffer
|
flip()
Flips this buffer. |
abstract
byte
|
get()
Relative get method. |
ByteBuffer
|
get(int index, byte[] dst)
Absolute bulk get method. |
ByteBuffer
|
get(byte[] dst, int offset, int length)
Relative bulk get method. |
ByteBuffer
|
get(int index, byte[] dst, int offset, int length)
Absolute bulk get method. |
abstract
byte
|
get(int index)
Absolute get method. |
ByteBuffer
|
get(byte[] dst)
Relative bulk get method. |
abstract
char
|
getChar()
Relative get method for reading a char value. |
abstract
char
|
getChar(int index)
Absolute get method for reading a char value. |
abstract
double
|
getDouble(int index)
Absolute get method for reading a double value. |
abstract
double
|
getDouble()
Relative get method for reading a double value. |
abstract
float
|
getFloat()
Relative get method for reading a float value. |
abstract
float
|
getFloat(int index)
Absolute get method for reading a float value. |
abstract
int
|
getInt(int index)
Absolute get method for reading an int value. |
abstract
int
|
getInt()
Relative get method for reading an int value. |
abstract
long
|
getLong(int index)
Absolute get method for reading a long value. |
abstract
long
|
getLong()
Relative get method for reading a long value. |
abstract
short
|
getShort(int index)
Absolute get method for reading a short value. |
abstract
short
|
getShort()
Relative get method for reading a short value. |
final
boolean
|
hasArray()
Tells whether or not this buffer is backed by an accessible byte array. |
int
|
hashCode()
Returns the current hash code of this buffer. |
abstract
boolean
|
isDirect()
Tells whether or not this byte buffer is direct. |
Buffer
|
limit(int newLimit)
Sets this buffer's limit. |
Buffer
|
mark()
Sets this buffer's mark at its position. |
int
|
mismatch(ByteBuffer that)
Finds and returns the relative index of the first mismatch between this buffer and a given buffer. |
final
ByteOrder
|
order()
Retrieves this buffer's byte order. |
final
ByteBuffer
|
order(ByteOrder bo)
Modifies this buffer's byte order. |
Buffer
|
position(int newPosition)
Sets this buffer's position. |
final
ByteBuffer
|
put(byte[] src)
Relative bulk put method (optional operation). |
ByteBuffer
|
put(int index, byte[] src, int offset, int length)
Absolute bulk put method (optional operation). |
abstract
ByteBuffer
|
put(byte b)
Relative put method (optional operation). |
ByteBuffer
|
put(byte[] src, int offset, int length)
Relative bulk put method (optional operation). |
ByteBuffer
|
put(int index, ByteBuffer src, int offset, int length)
Absolute bulk put method (optional operation). |
ByteBuffer
|
put(int index, byte[] src)
Absolute bulk put method (optional operation). |
abstract
ByteBuffer
|
put(int index, byte b)
Absolute put method (optional operation). |
ByteBuffer
|
put(ByteBuffer src)
Relative bulk put method (optional operation). |
abstract
ByteBuffer
|
putChar(int index, char value)
Absolute put method for writing a char value (optional operation). |
abstract
ByteBuffer
|
putChar(char value)
Relative put method for writing a char value (optional operation). |
abstract
ByteBuffer
|
putDouble(double value)
Relative put method for writing a double value (optional operation). |
abstract
ByteBuffer
|
putDouble(int index, double value)
Absolute put method for writing a double value (optional operation). |
abstract
ByteBuffer
|
putFloat(int index, float value)
Absolute put method for writing a float value (optional operation). |
abstract
ByteBuffer
|
putFloat(float value)
Relative put method for writing a float value (optional operation). |
abstract
ByteBuffer
|
putInt(int index, int value)
Absolute put method for writing an int value (optional operation). |
abstract
ByteBuffer
|
putInt(int value)
Relative put method for writing an int value (optional operation). |
abstract
ByteBuffer
|
putLong(long value)
Relative put method for writing a long value (optional operation). |
abstract
ByteBuffer
|
putLong(int index, long value)
Absolute put method for writing a long value (optional operation). |
abstract
ByteBuffer
|
putShort(short value)
Relative put method for writing a short value (optional operation). |
abstract
ByteBuffer
|
putShort(int index, short value)
Absolute put method for writing a short value (optional operation). |
Buffer
|
reset()
Resets this buffer's position to the previously-marked position. |
Buffer
|
rewind()
Rewinds this buffer. |
abstract
ByteBuffer
|
slice()
Creates a new byte buffer whose content is a shared subsequence of this buffer's content. |
abstract
ByteBuffer
|
slice(int index, int length)
Creates a new byte buffer whose content is a shared subsequence of this buffer's content. |
String
|
toString()
Returns a string summarizing the state of this buffer. |
static
ByteBuffer
|
wrap(byte[] array)
Wraps a byte array into a buffer. |
static
ByteBuffer
|
wrap(byte[] array, int offset, int length)
Wraps a byte array into a buffer. |
Inherited methods | |
---|---|
Public methods
alignedSlice
public final ByteBuffer alignedSlice (int unitSize)
Creates a new byte buffer whose content is a shared and aligned subsequence of this buffer's content.
The content of the new buffer will start at this buffer's current
position rounded up to the index of the nearest aligned byte for the
given unit size, and end at this buffer's limit rounded down to the index
of the nearest aligned byte for the given unit size.
If rounding results in out-of-bound values then the new buffer's capacity
and limit will be zero. If rounding is within bounds the following
expressions will be true for a new buffer nb
and unit size
unitSize
:
nb.alignmentOffset(0, unitSize) == 0
nb.alignmentOffset(nb.limit(), unitSize) == 0
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 bytes remaining in this buffer or fewer subject to
alignment, its mark will be undefined, and its byte order will be
BIG_ENDIAN
.
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.
API Note:
- This method may be utilized to create a new buffer where unit size bytes from index, that is a multiple of the unit size, may be accessed atomically, if supported by the native platform.
Implementation Note:
- This implementation throws
UnsupportedOperationException
for non-direct buffers when the given unit size is greater than8
.
Parameters | |
---|---|
unitSize |
int : The unit size in bytes, must be a power of 2 |
Returns | |
---|---|
ByteBuffer |
The new byte buffer |
Throws | |
---|---|
IllegalArgumentException |
If the unit size not a power of 2 |
UnsupportedOperationException |
If the native platform does not guarantee stable aligned slices for the given unit size when managing the memory regions of buffers of the same kind as this buffer (direct or non-direct). For example, if garbage collection would result in the moving of a memory region covered by a non-direct buffer from one location to another and both locations have different alignment characteristics. |
See also:
alignmentOffset
public final int alignmentOffset (int index, int unitSize)
Returns the memory address, pointing to the byte at the given index, modulo the given unit size.
The return value is non-negative in the range of 0
(inclusive) up to unitSize
(exclusive), with zero indicating
that the address of the byte at the index is aligned for the unit size,
and a positive value that the address is misaligned for the unit size.
If the address of the byte at the index is misaligned, the return value
represents how much the index should be adjusted to locate a byte at an
aligned address. Specifically, the index should either be decremented by
the return value if the latter is not greater than index
, or be
incremented by the unit size minus the return value. Therefore given
then the identities int value = alignmentOffset(index, unitSize)
and alignmentOffset(index - value, unitSize) == 0, value ≤ index
must hold. alignmentOffset(index + (unitSize - value), unitSize) == 0
API Note:
- This method may be utilized to determine if unit size bytes from an index can be accessed atomically, if supported by the native platform.
Implementation Note:
- This implementation throws
UnsupportedOperationException
for non-direct buffers when the given unit size is greater than8
.
Parameters | |
---|---|
index |
int : The index to query for alignment offset, must be non-negative, no
upper bounds check is performed |
unitSize |
int : The unit size in bytes, must be a power of 2 |
Returns | |
---|---|
int |
The indexed byte's memory address modulo the unit size |
Throws | |
---|---|
IllegalArgumentException |
If the index is negative or the unit size is not a power of
2 |
UnsupportedOperationException |
If the native platform does not guarantee stable alignment offset values for the given unit size when managing the memory regions of buffers of the same kind as this buffer (direct or non-direct). For example, if garbage collection would result in the moving of a memory region covered by a non-direct buffer from one location to another and both locations have different alignment characteristics. |
See also:
allocate
public static ByteBuffer allocate (int capacity)
Allocates a new byte 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
BIG_ENDIAN
.
It will have a backing array
, and its
array offset
will be zero.
Parameters | |
---|---|
capacity |
int : The new buffer's capacity, in bytes |
Returns | |
---|---|
ByteBuffer |
The new byte buffer |
Throws | |
---|---|
IllegalArgumentException |
If the capacity is a negative integer |
allocateDirect
public static ByteBuffer allocateDirect (int capacity)
Allocates a new direct byte 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
BIG_ENDIAN
. Whether or not it has a
backing array
is unspecified.
Parameters | |
---|---|
capacity |
int : The new buffer's capacity, in bytes |
Returns | |
---|---|
ByteBuffer |
The new byte buffer |
Throws | |
---|---|
IllegalArgumentException |
If the capacity is a negative integer |
array
public final byte[] array ()
Returns the byte 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.
Returns | |
---|---|
byte[] |
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 |
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 hasArray
method before invoking this
method in order to ensure that this buffer has an accessible backing
array.
Returns | |
---|---|
int |
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 |
asCharBuffer
public abstract CharBuffer asCharBuffer ()
Creates a view of this byte buffer as a char buffer.
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 bytes remaining in this buffer divided by two, its mark will be undefined, and its byte order will be that of the byte buffer at the moment the view is created. 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 | |
---|---|
CharBuffer |
A new char buffer |
asDoubleBuffer
public abstract DoubleBuffer asDoubleBuffer ()
Creates a view of this byte buffer as a double buffer.
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 bytes remaining in this buffer divided by eight, its mark will be undefined, and its byte order will be that of the byte buffer at the moment the view is created. 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 | |
---|---|
DoubleBuffer |
A new double buffer |
asFloatBuffer
public abstract FloatBuffer asFloatBuffer ()
Creates a view of this byte buffer as a float buffer.
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 bytes remaining in this buffer divided by four, its mark will be undefined, and its byte order will be that of the byte buffer at the moment the view is created. 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 | |
---|---|
FloatBuffer |
A new float buffer |
asIntBuffer
public abstract IntBuffer asIntBuffer ()
Creates a view of this byte buffer as an int buffer.
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 bytes remaining in this buffer divided by four, its mark will be undefined, and its byte order will be that of the byte buffer at the moment the view is created. 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 | |
---|---|
IntBuffer |
A new int buffer |
asLongBuffer
public abstract LongBuffer asLongBuffer ()
Creates a view of this byte buffer as a long buffer.
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 bytes remaining in this buffer divided by eight, its mark will be undefined, and its byte order will be that of the byte buffer at the moment the view is created. 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 | |
---|---|
LongBuffer |
A new long buffer |
asReadOnlyBuffer
public abstract ByteBuffer asReadOnlyBuffer ()
Creates a new, read-only byte 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, and its byte
order will be BIG_ENDIAN
.
If this buffer is itself read-only then this method behaves in
exactly the same way as the duplicate
method.
Returns | |
---|---|
ByteBuffer |
The new, read-only byte buffer |
asShortBuffer
public abstract ShortBuffer asShortBuffer ()
Creates a view of this byte buffer as a short buffer.
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 bytes remaining in this buffer divided by two, its mark will be undefined, and its byte order will be that of the byte buffer at the moment the view is created. 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 | |
---|---|
ShortBuffer |
A new short buffer |
clear
public Buffer clear ()
Clears 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.
Returns | |
---|---|
Buffer |
This buffer |
compact
public abstract ByteBuffer compact ()
Compacts this buffer (optional operation).
The bytes between the buffer's current position and its limit,
if any, are copied to the beginning of the buffer. That is, the
byte at index p = position()
is copied
to index zero, the byte at index p + 1 is copied
to index one, and so forth until the byte 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 bytes copied, rather than to zero, so that an invocation of this method can be followed immediately by an invocation of another relative put method.
Invoke this method after writing data from a buffer in case the
write was incomplete. The following loop, for example, copies bytes
from one channel to another via the buffer buf
:
buf.clear(); // Prepare buffer for use while (in.read(buf) >= 0 || buf.position != 0) { buf.flip(); out.write(buf); buf.compact(); // In case of partial write }
Returns | |
---|---|
ByteBuffer |
This buffer |
Throws | |
---|---|
ReadOnlyBufferException |
If this buffer is read-only |
compareTo
public int compareTo (ByteBuffer that)
Compares this buffer to another.
Two byte 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 byte
elements are compared as if by invoking
Byte#compare(byte,byte)
.
A byte buffer is not comparable to any other type of object.
Parameters | |
---|---|
that |
ByteBuffer |
Returns | |
---|---|
int |
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 ByteBuffer duplicate ()
Creates a new byte 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, and its byte
order will be BIG_ENDIAN
.
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 | |
---|---|
ByteBuffer |
The new byte buffer |
equals
public boolean equals (Object ob)
Tells whether or not this buffer is equal to another object.
Two byte 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 byte buffer is not equal to any other type of object.
Parameters | |
---|---|
ob |
Object : The object to which this buffer is to be compared |
Returns | |
---|---|
boolean |
true if, and only if, this buffer is equal to the
given object |
flip
public Buffer flip ()
Flips 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 compact
method when transferring data from
one place to another.
Returns | |
---|---|
Buffer |
This buffer |
get
public abstract byte get ()
Relative get method. Reads the byte at this buffer's current position, and then increments the position.
Returns | |
---|---|
byte |
The byte at the buffer's current position |
Throws | |
---|---|
BufferUnderflowException |
If the buffer's current position is not smaller than its limit |
get
public ByteBuffer get (int index, byte[] dst)
Absolute bulk get method.
This method transfers bytes 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 |
int : The index in this buffer from which the first byte will be
read; must be non-negative and less than limit() |
dst |
byte : The destination array |
Returns | |
---|---|
ByteBuffer |
This buffer |
Throws | |
---|---|
IndexOutOfBoundsException |
If index is negative, not smaller than limit() ,
or limit() - index < dst.length |
get
public ByteBuffer get (byte[] dst, int offset, int length)
Relative bulk get method.
This method transfers bytes from this buffer into the given
destination array. If there are fewer bytes remaining in the
buffer than are required to satisfy the request, that is, if
length
>
remaining()
, then no
bytes are transferred and a BufferUnderflowException
is
thrown.
Otherwise, this method copies length
bytes 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();
Parameters | |
---|---|
dst |
byte : The array into which bytes are to be written |
offset |
int : The offset within the array of the first byte to be
written; must be non-negative and no larger than
dst.length |
length |
int : The maximum number of bytes to be written to the given
array; must be non-negative and no larger than
dst.length - offset |
Returns | |
---|---|
ByteBuffer |
This buffer |
Throws | |
---|---|
BufferUnderflowException |
If there are fewer than length bytes
remaining in this buffer |
IndexOutOfBoundsException |
If the preconditions on the offset and length
parameters do not hold |
get
public ByteBuffer get (int index, byte[] dst, int offset, int length)
Absolute bulk get method.
This method transfers length
bytes 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 |
int : The index in this buffer from which the first byte will be
read; must be non-negative and less than limit() |
dst |
byte : The destination array |
offset |
int : The offset within the array of the first byte to be
written; must be non-negative and less than
dst.length |
length |
int : The number of bytes to be written to the given array;
must be non-negative and no larger than the smaller of
limit() - index and dst.length - offset |
Returns | |
---|---|
ByteBuffer |
This buffer |
Throws | |
---|---|
IndexOutOfBoundsException |
If the preconditions on the index , offset , and
length parameters do not hold |
get
public abstract byte get (int index)
Absolute get method. Reads the byte at the given index.
Parameters | |
---|---|
index |
int : The index from which the byte will be read |
Returns | |
---|---|
byte |
The byte at the given index |
Throws | |
---|---|
IndexOutOfBoundsException |
If index is negative
or not smaller than the buffer's limit |
get
public ByteBuffer get (byte[] dst)
Relative bulk get method.
This method transfers bytes 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 |
byte : The destination array |
Returns | |
---|---|
ByteBuffer |
This buffer |
Throws | |
---|---|
BufferUnderflowException |
If there are fewer than length bytes
remaining in this buffer |
getChar
public abstract char getChar ()
Relative get method for reading a char value.
Reads the next two bytes at this buffer's current position, composing them into a char value according to the current byte order, and then increments the position by two.
Returns | |
---|---|
char |
The char value at the buffer's current position |
Throws | |
---|---|
BufferUnderflowException |
If there are fewer than two bytes remaining in this buffer |
getChar
public abstract char getChar (int index)
Absolute get method for reading a char value.
Reads two bytes at the given index, composing them into a char value according to the current byte order.
Parameters | |
---|---|
index |
int : The index from which the bytes will be read |
Returns | |
---|---|
char |
The char value at the given index |
Throws | |
---|---|
IndexOutOfBoundsException |
If index is negative
or not smaller than the buffer's limit,
minus one |
getDouble
public abstract double getDouble (int index)
Absolute get method for reading a double value.
Reads eight bytes at the given index, composing them into a double value according to the current byte order.
Parameters | |
---|---|
index |
int : The index from which the bytes will be read |
Returns | |
---|---|
double |
The double value at the given index |
Throws | |
---|---|
IndexOutOfBoundsException |
If index is negative
or not smaller than the buffer's limit,
minus seven |
getDouble
public abstract double getDouble ()
Relative get method for reading a double value.
Reads the next eight bytes at this buffer's current position, composing them into a double value according to the current byte order, and then increments the position by eight.
Returns | |
---|---|
double |
The double value at the buffer's current position |
Throws | |
---|---|
BufferUnderflowException |
If there are fewer than eight bytes remaining in this buffer |
getFloat
public abstract float getFloat ()
Relative get method for reading a float value.
Reads the next four bytes at this buffer's current position, composing them into a float value according to the current byte order, and then increments the position by four.
Returns | |
---|---|
float |
The float value at the buffer's current position |
Throws | |
---|---|
BufferUnderflowException |
If there are fewer than four bytes remaining in this buffer |
getFloat
public abstract float getFloat (int index)
Absolute get method for reading a float value.
Reads four bytes at the given index, composing them into a float value according to the current byte order.
Parameters | |
---|---|
index |
int : The index from which the bytes will be read |
Returns | |
---|---|
float |
The float value at the given index |
Throws | |
---|---|
IndexOutOfBoundsException |
If index is negative
or not smaller than the buffer's limit,
minus three |
getInt
public abstract int getInt (int index)
Absolute get method for reading an int value.
Reads four bytes at the given index, composing them into a int value according to the current byte order.
Parameters | |
---|---|
index |
int : The index from which the bytes will be read |
Returns | |
---|---|
int |
The int value at the given index |
Throws | |
---|---|
IndexOutOfBoundsException |
If index is negative
or not smaller than the buffer's limit,
minus three |
getInt
public abstract int getInt ()
Relative get method for reading an int value.
Reads the next four bytes at this buffer's current position, composing them into an int value according to the current byte order, and then increments the position by four.
Returns | |
---|---|
int |
The int value at the buffer's current position |
Throws | |
---|---|
BufferUnderflowException |
If there are fewer than four bytes remaining in this buffer |
getLong
public abstract long getLong (int index)
Absolute get method for reading a long value.
Reads eight bytes at the given index, composing them into a long value according to the current byte order.
Parameters | |
---|---|
index |
int : The index from which the bytes will be read |
Returns | |
---|---|
long |
The long value at the given index |
Throws | |
---|---|
IndexOutOfBoundsException |
If index is negative
or not smaller than the buffer's limit,
minus seven |
getLong
public abstract long getLong ()
Relative get method for reading a long value.
Reads the next eight bytes at this buffer's current position, composing them into a long value according to the current byte order, and then increments the position by eight.
Returns | |
---|---|
long |
The long value at the buffer's current position |
Throws | |
---|---|
BufferUnderflowException |
If there are fewer than eight bytes remaining in this buffer |
getShort
public abstract short getShort (int index)
Absolute get method for reading a short value.
Reads two bytes at the given index, composing them into a short value according to the current byte order.
Parameters | |
---|---|
index |
int : The index from which the bytes will be read |
Returns | |
---|---|
short |
The short value at the given index |
Throws | |
---|---|
IndexOutOfBoundsException |
If index is negative
or not smaller than the buffer's limit,
minus one |
getShort
public abstract short getShort ()
Relative get method for reading a short value.
Reads the next two bytes at this buffer's current position, composing them into a short value according to the current byte order, and then increments the position by two.
Returns | |
---|---|
short |
The short value at the buffer's current position |
Throws | |
---|---|
BufferUnderflowException |
If there are fewer than two bytes remaining in this buffer |
hasArray
public final boolean hasArray ()
Tells whether or not this buffer is backed by an accessible byte array.
If this method returns true
then the array
and arrayOffset
methods may safely be invoked.
Returns | |
---|---|
boolean |
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 byte 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.
Returns | |
---|---|
int |
The current hash code of this buffer |
isDirect
public abstract boolean isDirect ()
Tells whether or not this byte buffer is direct.
Returns | |
---|---|
boolean |
true if, and only if, this buffer is direct |
limit
public Buffer limit (int newLimit)
Sets 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.
Parameters | |
---|---|
newLimit |
int : The new limit value; must be non-negative
and no larger than this buffer's capacity |
Returns | |
---|---|
Buffer |
This buffer |
mark
public Buffer mark ()
Sets this buffer's mark at its position.
Returns | |
---|---|
Buffer |
This buffer |
mismatch
public int mismatch (ByteBuffer that)
Finds and returns the relative index of the first mismatch between this
buffer and a given buffer. The index is relative to the
position
of each buffer and will be in the range of
0 (inclusive) up to the smaller of the remaining
elements 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 |
ByteBuffer : The byte buffer to be tested for a mismatch with this buffer |
Returns | |
---|---|
int |
The relative index of the first mismatch between this and the given buffer, otherwise -1 if no mismatch. |
order
public final ByteOrder order ()
Retrieves this buffer's byte order.
The byte order is used when reading or writing multibyte values, and
when creating buffers that are views of this byte buffer. The order of
a newly-created byte buffer is always BIG_ENDIAN
.
Returns | |
---|---|
ByteOrder |
This buffer's byte order |
order
public final ByteBuffer order (ByteOrder bo)
Modifies this buffer's byte order.
Parameters | |
---|---|
bo |
ByteOrder : The new byte order,
either BIG_ENDIAN
or LITTLE_ENDIAN |
Returns | |
---|---|
ByteBuffer |
This buffer |
position
public Buffer position (int newPosition)
Sets this buffer's position. If the mark is defined and larger than the new position then it is discarded.
Parameters | |
---|---|
newPosition |
int : The new position value; must be non-negative
and no larger than the current limit |
Returns | |
---|---|
Buffer |
This buffer |
put
public final ByteBuffer put (byte[] src)
Relative bulk put method (optional operation).
This method transfers the entire content of the given source
byte 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 |
byte : The source array |
Returns | |
---|---|
ByteBuffer |
This buffer |
Throws | |
---|---|
BufferOverflowException |
If there is insufficient space in this buffer |
ReadOnlyBufferException |
If this buffer is read-only |
put
public ByteBuffer put (int index, byte[] src, int offset, int length)
Absolute bulk put method (optional operation).
This method transfers length
bytes 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 |
int : The index in this buffer at which the first byte will be
written; must be non-negative and less than limit() |
src |
byte : The array from which bytes are to be read |
offset |
int : The offset within the array of the first byte to be read;
must be non-negative and less than src.length |
length |
int : The number of bytes to be read from the given array;
must be non-negative and no larger than the smaller of
limit() - index and src.length - offset |
Returns | |
---|---|
ByteBuffer |
This buffer |
Throws | |
---|---|
IndexOutOfBoundsException |
If the preconditions on the index , offset , and
length parameters do not hold |
ReadOnlyBufferException |
If this buffer is read-only |
put
public abstract ByteBuffer put (byte b)
Relative put method (optional operation).
Writes the given byte into this buffer at the current position, and then increments the position.
Parameters | |
---|---|
b |
byte : The byte to be written |
Returns | |
---|---|
ByteBuffer |
This buffer |
Throws | |
---|---|
BufferOverflowException |
If this buffer's current position is not smaller than its limit |
ReadOnlyBufferException |
If this buffer is read-only |
put
public ByteBuffer put (byte[] src, int offset, int length)
Relative bulk put method (optional operation).
This method transfers bytes into this buffer from the given
source array. If there are more bytes to be copied from the array
than remain in this buffer, that is, if
length
>
remaining()
, then no
bytes are transferred and a BufferOverflowException
is
thrown.
Otherwise, this method copies length
bytes 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(src[i]);
Parameters | |
---|---|
src |
byte : The array from which bytes are to be read |
offset |
int : The offset within the array of the first byte to be read;
must be non-negative and no larger than src.length |
length |
int : The number of bytes to be read from the given array;
must be non-negative and no larger than
src.length - offset |
Returns | |
---|---|
ByteBuffer |
This buffer |
Throws | |
---|---|
BufferOverflowException |
If there is insufficient space in this buffer |
IndexOutOfBoundsException |
If the preconditions on the offset and length
parameters do not hold |
ReadOnlyBufferException |
If this buffer is read-only |
put
public ByteBuffer put (int index, ByteBuffer src, int offset, int length)
Absolute bulk put method (optional operation).
This method transfers length
bytes into this buffer from
the given source buffer, starting at the given offset
in the
source buffer and the given index
in 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
for (int i = offset, j = index; i < offset + length; i++, j++)
dst.put(j, src.get(i));
Parameters | |
---|---|
index |
int : The index in this buffer at which the first byte will be
written; must be non-negative and less than limit() |
src |
ByteBuffer : The buffer from which bytes are to be read |
offset |
int : The index within the source buffer of the first byte to be
read; must be non-negative and less than src.limit() |
length |
int : The number of bytes to be read from the given buffer;
must be non-negative and no larger than the smaller of
limit() - index and src.limit() - offset |
Returns | |
---|---|
ByteBuffer |
This buffer |
Throws | |
---|---|
IndexOutOfBoundsException |
If the preconditions on the index , offset , and
length parameters do not hold |
ReadOnlyBufferException |
If this buffer is read-only |
put
public ByteBuffer put (int index, byte[] src)
Absolute bulk put method (optional operation).
This method copies bytes 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 |
int : The index in this buffer at which the first byte will be
written; must be non-negative and less than limit() |
src |
byte : The array from which bytes are to be read |
Returns | |
---|---|
ByteBuffer |
This buffer |
Throws | |
---|---|
IndexOutOfBoundsException |
If index is negative, not smaller than limit() ,
or limit() - index < src.length |
ReadOnlyBufferException |
If this buffer is read-only |
put
public abstract ByteBuffer put (int index, byte b)
Absolute put method (optional operation).
Writes the given byte into this buffer at the given index.
Parameters | |
---|---|
index |
int : The index at which the byte will be written |
b |
byte : The byte value to be written |
Returns | |
---|---|
ByteBuffer |
This buffer |
Throws | |
---|---|
IndexOutOfBoundsException |
If index is negative
or not smaller than the buffer's limit |
ReadOnlyBufferException |
If this buffer is read-only |
put
public ByteBuffer put (ByteBuffer src)
Relative bulk put method (optional operation).
This method transfers the bytes remaining in the given source
buffer into this buffer. If there are more bytes remaining in the
source buffer than in this buffer, that is, if
src.remaining()
>
remaining()
,
then no bytes are transferred and a BufferOverflowException
is thrown.
Otherwise, this method copies
n = src.remaining()
bytes 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());
Parameters | |
---|---|
src |
ByteBuffer : The source buffer from which bytes are to be read;
must not be this buffer |
Returns | |
---|---|
ByteBuffer |
This buffer |
Throws | |
---|---|
BufferOverflowException |
If there is insufficient space in this buffer for the remaining bytes in the source buffer |
IllegalArgumentException |
If the source buffer is this buffer |
ReadOnlyBufferException |
If this buffer is read-only |
putChar
public abstract ByteBuffer putChar (int index, char value)
Absolute put method for writing a char value (optional operation).
Writes two bytes containing the given char value, in the current byte order, into this buffer at the given index.
Parameters | |
---|---|
index |
int : The index at which the bytes will be written |
value |
char : The char value to be written |
Returns | |
---|---|
ByteBuffer |
This buffer |
Throws | |
---|---|
IndexOutOfBoundsException |
If index is negative
or not smaller than the buffer's limit,
minus one |
ReadOnlyBufferException |
If this buffer is read-only |
putChar
public abstract ByteBuffer putChar (char value)
Relative put method for writing a char value (optional operation).
Writes two bytes containing the given char value, in the current byte order, into this buffer at the current position, and then increments the position by two.
Parameters | |
---|---|
value |
char : The char value to be written |
Returns | |
---|---|
ByteBuffer |
This buffer |
Throws | |
---|---|
BufferOverflowException |
If there are fewer than two bytes remaining in this buffer |
ReadOnlyBufferException |
If this buffer is read-only |
putDouble
public abstract ByteBuffer putDouble (double value)
Relative put method for writing a double value (optional operation).
Writes eight bytes containing the given double value, in the current byte order, into this buffer at the current position, and then increments the position by eight.
Parameters | |
---|---|
value |
double : The double value to be written |
Returns | |
---|---|
ByteBuffer |
This buffer |
Throws | |
---|---|
BufferOverflowException |
If there are fewer than eight bytes remaining in this buffer |
ReadOnlyBufferException |
If this buffer is read-only |
putDouble
public abstract ByteBuffer putDouble (int index, double value)
Absolute put method for writing a double value (optional operation).
Writes eight bytes containing the given double value, in the current byte order, into this buffer at the given index.
Parameters | |
---|---|
index |
int : The index at which the bytes will be written |
value |
double : The double value to be written |
Returns | |
---|---|
ByteBuffer |
This buffer |
Throws | |
---|---|
IndexOutOfBoundsException |
If index is negative
or not smaller than the buffer's limit,
minus seven |
ReadOnlyBufferException |
If this buffer is read-only |
putFloat
public abstract ByteBuffer putFloat (int index, float value)
Absolute put method for writing a float value (optional operation).
Writes four bytes containing the given float value, in the current byte order, into this buffer at the given index.
Parameters | |
---|---|
index |
int : The index at which the bytes will be written |
value |
float : The float value to be written |
Returns | |
---|---|
ByteBuffer |
This buffer |
Throws | |
---|---|
IndexOutOfBoundsException |
If index is negative
or not smaller than the buffer's limit,
minus three |
ReadOnlyBufferException |
If this buffer is read-only |
putFloat
public abstract ByteBuffer putFloat (float value)
Relative put method for writing a float value (optional operation).
Writes four bytes containing the given float value, in the current byte order, into this buffer at the current position, and then increments the position by four.
Parameters | |
---|---|
value |
float : The float value to be written |
Returns | |
---|---|
ByteBuffer |
This buffer |
Throws | |
---|---|
BufferOverflowException |
If there are fewer than four bytes remaining in this buffer |
ReadOnlyBufferException |
If this buffer is read-only |
putInt
public abstract ByteBuffer putInt (int index, int value)
Absolute put method for writing an int value (optional operation).
Writes four bytes containing the given int value, in the current byte order, into this buffer at the given index.
Parameters | |
---|---|
index |
int : The index at which the bytes will be written |
value |
int : The int value to be written |
Returns | |
---|---|
ByteBuffer |
This buffer |
Throws | |
---|---|
IndexOutOfBoundsException |
If index is negative
or not smaller than the buffer's limit,
minus three |
ReadOnlyBufferException |
If this buffer is read-only |
putInt
public abstract ByteBuffer putInt (int value)
Relative put method for writing an int value (optional operation).
Writes four bytes containing the given int value, in the current byte order, into this buffer at the current position, and then increments the position by four.
Parameters | |
---|---|
value |
int : The int value to be written |
Returns | |
---|---|
ByteBuffer |
This buffer |
Throws | |
---|---|
BufferOverflowException |
If there are fewer than four bytes remaining in this buffer |
ReadOnlyBufferException |
If this buffer is read-only |
putLong
public abstract ByteBuffer putLong (long value)
Relative put method for writing a long value (optional operation).
Writes eight bytes containing the given long value, in the current byte order, into this buffer at the current position, and then increments the position by eight.
Parameters | |
---|---|
value |
long : The long value to be written |
Returns | |
---|---|
ByteBuffer |
This buffer |
Throws | |
---|---|
BufferOverflowException |
If there are fewer than eight bytes remaining in this buffer |
ReadOnlyBufferException |
If this buffer is read-only |
putLong
public abstract ByteBuffer putLong (int index, long value)
Absolute put method for writing a long value (optional operation).
Writes eight bytes containing the given long value, in the current byte order, into this buffer at the given index.
Parameters | |
---|---|
index |
int : The index at which the bytes will be written |
value |
long : The long value to be written |
Returns | |
---|---|
ByteBuffer |
This buffer |
Throws | |
---|---|
IndexOutOfBoundsException |
If index is negative
or not smaller than the buffer's limit,
minus seven |
ReadOnlyBufferException |
If this buffer is read-only |
putShort
public abstract ByteBuffer putShort (short value)
Relative put method for writing a short value (optional operation).
Writes two bytes containing the given short value, in the current byte order, into this buffer at the current position, and then increments the position by two.
Parameters | |
---|---|
value |
short : The short value to be written |
Returns | |
---|---|
ByteBuffer |
This buffer |
Throws | |
---|---|
BufferOverflowException |
If there are fewer than two bytes remaining in this buffer |
ReadOnlyBufferException |
If this buffer is read-only |
putShort
public abstract ByteBuffer putShort (int index, short value)
Absolute put method for writing a short value (optional operation).
Writes two bytes containing the given short value, in the current byte order, into this buffer at the given index.
Parameters | |
---|---|
index |
int : The index at which the bytes will be written |
value |
short : The short value to be written |
Returns | |
---|---|
ByteBuffer |
This buffer |
Throws | |
---|---|
IndexOutOfBoundsException |
If index is negative
or not smaller than the buffer's limit,
minus one |
ReadOnlyBufferException |
If this buffer is read-only |
reset
public Buffer reset ()
Resets this buffer's position to the previously-marked position.
Invoking this method neither changes nor discards the mark's value.
Returns | |
---|---|
Buffer |
This buffer |
rewind
public Buffer rewind ()
Rewinds 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
Returns | |
---|---|
Buffer |
This buffer |
slice
public abstract ByteBuffer slice ()
Creates a new byte 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 bytes remaining in this buffer, its mark will be
undefined, and its byte order will be
BIG_ENDIAN
.
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 | |
---|---|
ByteBuffer |
The new byte buffer |
See also:
slice
public abstract ByteBuffer slice (int index, int length)
Creates a new byte buffer whose content is a shared subsequence of this buffer's content.
The content of the new buffer will start at position index
in this buffer, and will contain length
elements. 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
BIG_ENDIAN
.
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.
Parameters | |
---|---|
index |
int : 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 |
int : The number of elements the new buffer will contain; must be
non-negative and no larger than limit() - index |
Returns | |
---|---|
ByteBuffer |
The new buffer |
Throws | |
---|---|
IndexOutOfBoundsException |
If index is negative or greater than limit() ,
length is negative, or length > limit() - index |
toString
public String toString ()
Returns a string summarizing the state of this buffer.
Returns | |
---|---|
String |
A summary string |
wrap
public static ByteBuffer wrap (byte[] array)
Wraps a byte array into a buffer.
The new buffer will be backed by the given byte 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
BIG_ENDIAN
.
Its backing array
will be the given array, and its
array offset
will be zero.
Parameters | |
---|---|
array |
byte : The array that will back this buffer |
Returns | |
---|---|
ByteBuffer |
The new byte buffer |
wrap
public static ByteBuffer wrap (byte[] array, int offset, int length)
Wraps a byte array into a buffer.
The new buffer will be backed by the given byte 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
, its mark will be undefined, and its
byte order will be
BIG_ENDIAN
.
Its backing array
will be the given array, and
its array offset
will be zero.
Parameters | |
---|---|
array |
byte : The array that will back the new buffer |
offset |
int : 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 |
int : 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 | |
---|---|
ByteBuffer |
The new byte buffer |
Throws | |
---|---|
IndexOutOfBoundsException |
If the preconditions on the offset and length
parameters do not hold |