java.nio
public
abstract
class
java.nio.ByteBuffer
A buffer of byte
s.
A byte buffer can be created in either of the following ways:
- Allocate a new byte array and create a buffer
based on it;
- Allocate a memory block and create a direct
buffer based on it;
- Wrap an existing byte array to create a new
buffer.
Known Direct Subclasses
MappedByteBuffer |
MappedByteBuffer is a special kind of direct byte buffer,
which maps a region of file to memory. |
Summary
Public Methods
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ByteBuffer |
allocate(int capacity) |
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static |
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ByteBuffer |
allocateDirect(int capacity) |
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final |
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byte[] |
array() |
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final |
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int |
arrayOffset() |
abstract |
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CharBuffer |
asCharBuffer() |
abstract |
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DoubleBuffer |
asDoubleBuffer() |
abstract |
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FloatBuffer |
asFloatBuffer() |
abstract |
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IntBuffer |
asIntBuffer() |
abstract |
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LongBuffer |
asLongBuffer() |
abstract |
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ByteBuffer |
asReadOnlyBuffer() |
abstract |
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ShortBuffer |
asShortBuffer() |
abstract |
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ByteBuffer |
compact() |
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int |
compareTo(ByteBuffer otherBuffer) |
abstract |
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ByteBuffer |
duplicate() |
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boolean |
equals(Object other) |
abstract |
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byte |
get() |
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ByteBuffer |
get(byte[] dest, int off, int len) |
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ByteBuffer |
get(byte[] dest) |
abstract |
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byte |
get(int index) |
abstract |
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char |
getChar(int index) |
abstract |
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char |
getChar() |
abstract |
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double |
getDouble() |
abstract |
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double |
getDouble(int index) |
abstract |
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float |
getFloat() |
abstract |
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float |
getFloat(int index) |
abstract |
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int |
getInt(int index) |
abstract |
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int |
getInt() |
abstract |
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long |
getLong() |
abstract |
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long |
getLong(int index) |
abstract |
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short |
getShort(int index) |
abstract |
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short |
getShort() |
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final |
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boolean |
hasArray() |
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int |
hashCode() |
abstract |
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boolean |
isDirect() |
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final |
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ByteOrder |
order() |
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final |
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ByteBuffer |
order(ByteOrder byteOrder) |
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final |
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ByteBuffer |
put(byte[] src) |
abstract |
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ByteBuffer |
put(byte b) |
abstract |
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ByteBuffer |
put(int index, byte b) |
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ByteBuffer |
put(ByteBuffer src) |
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ByteBuffer |
put(byte[] src, int off, int len) |
abstract |
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ByteBuffer |
putChar(int index, char value) |
abstract |
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ByteBuffer |
putChar(char value) |
abstract |
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ByteBuffer |
putDouble(int index, double value) |
abstract |
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ByteBuffer |
putDouble(double value) |
abstract |
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ByteBuffer |
putFloat(int index, float value) |
abstract |
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ByteBuffer |
putFloat(float value) |
abstract |
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ByteBuffer |
putInt(int value) |
abstract |
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ByteBuffer |
putInt(int index, int value) |
abstract |
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ByteBuffer |
putLong(long value) |
abstract |
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ByteBuffer |
putLong(int index, long value) |
abstract |
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ByteBuffer |
putShort(int index, short value) |
abstract |
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ByteBuffer |
putShort(short value) |
abstract |
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ByteBuffer |
slice() |
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String |
toString() |
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static |
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ByteBuffer |
wrap(byte[] array) |
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static |
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ByteBuffer |
wrap(byte[] array, int start, int len) |
capacity,
clear,
flip,
hasRemaining,
isReadOnly,
limit,
limit,
mark,
position,
position,
remaining,
reset,
rewind
clone,
equals,
finalize,
getClass,
hashCode,
notify,
notifyAll,
toString,
wait,
wait,
wait
Details
Public Methods
public
static
ByteBuffer
allocate(int capacity)
Creates a byte buffer based on a new allocated byte array.
Parameters
capacity
| The capacity of the new buffer |
public
static
ByteBuffer
allocateDirect(int capacity)
Creates a direct byte buffer based on a new allocated memory block.
Parameters
capacity
| The capacity of the new buffer |
public
final
byte[]
array()
Returns the byte array which this buffer is based on, if there's one.
Returns
- The byte array which this buffer is based on
public
final
int
arrayOffset()
Returns the offset of the byte array which this buffer is based on, if
there's one.
The offset is the index of the array corresponds to the zero position of
the buffer.
Returns
- The offset of the byte array which this buffer is based on
public
abstract
CharBuffer
asCharBuffer()
Returns a char buffer which is based on the remaining content of
this byte buffer.
The new buffer's position is zero, its limit and capacity is
the number of remaining bytes divided by two, and its mark is not set.
The new buffer's readonly property and byte order are same as this
buffer. The new buffer is direct, if this byte buffer is direct.
The new buffer shares content with this buffer, which means
either buffer's change of content will be visible to the other.
The two buffer's position, limit and mark are independent.
Returns
- A char buffer which is based on the content of
this byte buffer.
public
abstract
DoubleBuffer
asDoubleBuffer()
Returns a double buffer which is based on the remaining content of
this byte buffer.
The new buffer's position is zero, its limit and capacity is
the number of remaining bytes divided by two, and its mark is not set.
The new buffer's readonly property and byte order are same as this
buffer. The new buffer is direct, if this byte buffer is direct.
The new buffer shares content with this buffer, which means
either buffer's change of content will be visible to the other.
The two buffer's position, limit and mark are independent.
Returns
- A double buffer which is based on the content of
this byte buffer.
public
abstract
FloatBuffer
asFloatBuffer()
Returns a float buffer which is based on the remaining content of
this byte buffer.
The new buffer's position is zero, its limit and capacity is
the number of remaining bytes divided by two, and its mark is not set.
The new buffer's readonly property and byte order are same as this
buffer. The new buffer is direct, if this byte buffer is direct.
The new buffer shares content with this buffer, which means
either buffer's change of content will be visible to the other.
The two buffer's position, limit and mark are independent.
Returns
- A float buffer which is based on the content of
this byte buffer.
public
abstract
IntBuffer
asIntBuffer()
Returns a int buffer which is based on the remaining content of
this byte buffer.
The new buffer's position is zero, its limit and capacity is
the number of remaining bytes divided by two, and its mark is not set.
The new buffer's readonly property and byte order are same as this
buffer. The new buffer is direct, if this byte buffer is direct.
The new buffer shares content with this buffer, which means
either buffer's change of content will be visible to the other.
The two buffer's position, limit and mark are independent.
Returns
- A int buffer which is based on the content of
this byte buffer.
public
abstract
LongBuffer
asLongBuffer()
Returns a long buffer which is based on the remaining content of
this byte buffer.
The new buffer's position is zero, its limit and capacity is
the number of remaining bytes divided by two, and its mark is not set.
The new buffer's readonly property and byte order are same as this
buffer. The new buffer is direct, if this byte buffer is direct.
The new buffer shares content with this buffer, which means
either buffer's change of content will be visible to the other.
The two buffer's position, limit and mark are independent.
Returns
- A long buffer which is based on the content of
this byte buffer.
public
abstract
ByteBuffer
asReadOnlyBuffer()
Returns a readonly buffer that shares content with this buffer.
The returned buffer is guaranteed to be a new instance, even this
buffer is readonly itself. The new buffer's position, limit, capacity
and mark are the same as this buffer.
The new buffer shares content with this buffer, which means
this buffer's change of content will be visible to the new buffer.
The two buffer's position, limit and mark are independent.
Returns
- A readonly version of this buffer.
public
abstract
ShortBuffer
asShortBuffer()
Returns a short buffer which is based on the remaining content of
this byte buffer.
The new buffer's position is zero, its limit and capacity is
the number of remaining bytes divided by two, and its mark is not set.
The new buffer's readonly property and byte order are same as this
buffer. The new buffer is direct, if this byte buffer is direct.
The new buffer shares content with this buffer, which means
either buffer's change of content will be visible to the other.
The two buffer's position, limit and mark are independent.
Returns
- A short buffer which is based on the content of
this byte buffer.
public
abstract
ByteBuffer
compact()
Compacts this byte buffer.
The remaining byte
s will be moved to the head of the
buffer, staring from position zero. Then the position is set to
remaining()
; the limit is set to capacity; the mark is
cleared.
public
int
compareTo(ByteBuffer otherBuffer)
Compare the remaining
byte
s of this buffer to another
byte buffer's remaining
byte
s.
Parameters
otherBuffer
| Another byte buffer |
Returns
- a negative value if this is less than
other
; 0 if
this equals to other
; a positive value if this is
greater than other
public
abstract
ByteBuffer
duplicate()
Returns a duplicated buffer that shares content with this buffer.
The duplicated buffer's position, limit, capacity and mark are the
same as this buffer. The duplicated buffer's readonly property and
byte order are same as this buffer too.
The new buffer shares content with this buffer, which means
either buffer's change of content will be visible to the other.
The two buffer's position, limit and mark are independent.
Returns
- A duplicated buffer that shares content with this buffer.
public
boolean
equals(Object other)
Tests whether this byte buffer equals to another object.
If other
is not a byte buffer, then false is returned.
Two byte buffers are equals if, and only if, their remaining
byte
s are exactly the same. Position, limit, capacity and
mark are not considered.
Parameters
other
| the object to compare against |
Returns
- Whether this byte buffer equals to another object.
public
abstract
byte
get()
Returns the byte at the current position and increase the position by 1.
Returns
- The byte at the current position.
public
ByteBuffer
get(byte[] dest, int off, int len)
Reads
byte
s from the current position into the specified
byte array, starting from the specified offset, and increase the position
by the number of
byte
s read.
Parameters
dest
| The target byte array |
off
| The offset of the byte array, must be no less than zero and no
greater than dest.length |
len
| The number of byte s to read, must be no less
than zero and no greater than dest.length - off |
public
ByteBuffer
get(byte[] dest)
Reads
byte
s from the current position into the specified
byte array and increase the position by the number of
byte
s
read.
Calling this method has the same effect as
get(dest, 0, dest.length)
.
Parameters
dest
| The destination byte array |
public
abstract
byte
get(int index)
Returns a byte at the specified index, and the position is not changed.
Parameters
index
| The index, must be no less than zero and less than limit |
Returns
- A byte at the specified index.
public
abstract
char
getChar(int index)
Returns the char at the specified index.
The 2 bytes start from the specified index are composed into a char
according to current byte order and returned. The position is not
changed.
Parameters
index
| The index, must be no less than zero and equal or less than
limit - 2 |
Returns
- The char at the specified index.
public
abstract
char
getChar()
Returns the char at the current position and increase the position by 2.
The 2 bytes start from the current position are composed into a char
according to current byte order and returned. The position increases by
2.
Returns
- The char at the current position.
public
abstract
double
getDouble()
Returns the double at the current position and increase the position by
8.
The 8 bytes start from the current position are composed into a double
according to current byte order and returned. The position increases by
8.
Returns
- The double at the current position.
public
abstract
double
getDouble(int index)
Returns the double at the specified index.
The 8 bytes start from the specified index are composed into a double
according to current byte order and returned. The position is not
changed.
Parameters
index
| The index, must be no less than zero and equal or less than
limit - 8 |
Returns
- The double at the specified index.
public
abstract
float
getFloat()
Returns the float at the current position and increase the position by 4.
The 4 bytes start from the current position are composed into a float
according to current byte order and returned. The position increases by
4.
Returns
- The float at the current position.
public
abstract
float
getFloat(int index)
Returns the float at the specified index.
The 4 bytes start from the specified index are composed into a float
according to current byte order and returned. The position is not
changed.
Parameters
index
| The index, must be no less than zero and equal or less than
limit - 4 |
Returns
- The float at the specified index.
public
abstract
int
getInt(int index)
Returns the int at the specified index.
The 4 bytes start from the specified index are composed into a int
according to current byte order and returned. The position is not
changed.
Parameters
index
| The index, must be no less than zero and equal or less than
limit - 4 |
Returns
- The int at the specified index.
public
abstract
int
getInt()
Returns the int at the current position and increase the position by 4.
The 4 bytes start from the current position are composed into a int
according to current byte order and returned.
The position increases by 4.
Returns
- The int at the current position.
public
abstract
long
getLong()
Returns the long at the current position and increase the position by 8.
The 8 bytes start from the current position are composed into a long
according to current byte order and returned. The position increases by
8.
Returns
- The long at the current position.
public
abstract
long
getLong(int index)
Returns the long at the specified index.
The 8 bytes start from the specified index are composed into a long
according to current byte order and returned. The position is not
changed.
Parameters
index
| The index, must be no less than zero and equal or less than
limit - 8 |
Returns
- The long at the specified index.
public
abstract
short
getShort(int index)
Returns the short at the specified index.
The 2 bytes start from the specified index are composed into a short
according to current byte order and returned. The position is not
changed.
Parameters
index
| The index, must be no less than zero and equal or less than
limit - 2 |
Returns
- The short at the specified index.
public
abstract
short
getShort()
Returns the short at the current position and increase the position by 2.
The 2 bytes start from the current position are composed into a short
according to current byte order and returned.
The position increases by 2.
Returns
- The short at the current position.
public
final
boolean
hasArray()
Returns whether this buffer is based on a byte array and is read/write.
If this buffer is readonly, then false is returned.
Returns
- Whether this buffer is based on a byte array and is read/write.
public
int
hashCode()
Hash code is calculated from the remaining
byte
s.
Position, limit, capacity and mark don't affect the hash code.
Returns
- The hash code calculated from the remaining
byte
s.
public
abstract
boolean
isDirect()
Returns true if this buffer is direct.
A byte buffer is direct, if it is based on a byte buffer and the byte
buffer is direct.
Returns
- True if this buffer is direct.
public
final
ByteOrder
order()
Returns the byte order used by this buffer when converting
byte
s from/to other primitive types.
The default byte order of byte buffer is always BIG_ENDIAN.
Returns
- The byte order used by this buffer when converting
byte
s from/to other primitive types.
Sets the byte order of this buffer.
Parameters
byteOrder
| The byte order to set. If null then the order
will be LITTLE_ENDIAN. |
public
final
ByteBuffer
put(byte[] src)
Writes
byte
s in the given byte array to the current
position and increase the position by the number of
byte
s
written.
Calling this method has the same effect as
put(src, 0, src.length)
.
Parameters
src
| The source byte array |
public
abstract
ByteBuffer
put(byte b)
Writes the given byte to the current position and increase the position
by 1.
public
abstract
ByteBuffer
put(int index, byte b)
Write a byte to the specified index of this buffer and the position is
not changed.
Parameters
index
| The index, must be no less than zero and less than the limit |
b
| The byte to write |
Writes all the remaining
byte
s of the
src
byte buffer to this buffer's current position, and increase both buffers'
position by the number of
byte
s copied.
Parameters
src
| The source byte buffer |
public
ByteBuffer
put(byte[] src, int off, int len)
Writes
byte
s in the given byte array, starting from the
specified offset, to the current position and increase the position by
the number of
byte
s written.
Parameters
src
| The source byte array |
off
| The offset of byte array, must be no less than zero and no
greater than src.length |
len
| The number of byte s to write, must be no less
than zero and no greater than src.length - off |
public
abstract
ByteBuffer
putChar(int index, char value)
Write a char to the specified index of this buffer.
The char is converted to bytes using the current byte order. The position
is not changed.
Parameters
index
| The index, must be no less than zero and equal or less than
limit - 2 |
value
| The char to write |
public
abstract
ByteBuffer
putChar(char value)
Writes the given char to the current position and increase the position
by 2.
The char is converted to bytes using the current byte order.
public
abstract
ByteBuffer
putDouble(int index, double value)
Write a double to the specified index of this buffer.
The double is converted to bytes using the current byte order. The
position is not changed.
Parameters
index
| The index, must be no less than zero and equal or less than
limit - 8 |
value
| The double to write |
public
abstract
ByteBuffer
putDouble(double value)
Writes the given double to the current position and increase the position
by 8.
The double is converted to bytes using the current byte order.
Parameters
value
| The double to write |
public
abstract
ByteBuffer
putFloat(int index, float value)
Write a float to the specified index of this buffer.
The float is converted to bytes using the current byte order. The
position is not changed.
Parameters
index
| The index, must be no less than zero and equal or less than
limit - 4 |
value
| The float to write |
public
abstract
ByteBuffer
putFloat(float value)
Writes the given float to the current position and increase the position
by 4.
The float is converted to bytes using the current byte order.
public
abstract
ByteBuffer
putInt(int value)
Writes the given int to the current position and increase the position by
4.
The int is converted to bytes using the current byte order.
public
abstract
ByteBuffer
putInt(int index, int value)
Write a int to the specified index of this buffer.
The int is converted to bytes using the current byte order. The position
is not changed.
Parameters
index
| The index, must be no less than zero and equal or less than
limit - 4 |
value
| The int to write |
public
abstract
ByteBuffer
putLong(long value)
Writes the given long to the current position and increase the position
by 8.
The long is converted to bytes using the current byte order.
public
abstract
ByteBuffer
putLong(int index, long value)
Write a long to the specified index of this buffer.
The long is converted to bytes using the current byte order. The position
is not changed.
Parameters
index
| The index, must be no less than zero and equal or less than
limit - 8 |
value
| The long to write |
public
abstract
ByteBuffer
putShort(int index, short value)
Write a short to the specified index of this buffer.
The short is converted to bytes using the current byte order. The
position is not changed.
Parameters
index
| The index, must be no less than zero and equal or less than
limit - 2 |
value
| The short to write |
public
abstract
ByteBuffer
putShort(short value)
Writes the given short to the current position and increase the position
by 2.
The short is converted to bytes using the current byte order.
public
abstract
ByteBuffer
slice()
Returns a sliced buffer that shares content with this buffer.
The sliced buffer's capacity will be this buffer's
remaining()
, and its zero position will correspond to
this buffer's current position. The new buffer's position will be
0, limit will be its capacity, and its mark is unset. The new buffer's
readonly property and byte order are same as this buffer.
The new buffer shares content with this buffer, which means
either buffer's change of content will be visible to the other.
The two buffer's position, limit and mark are independent.
Returns
- A sliced buffer that shares content with this buffer.
public
String
toString()
Returns a string represents the state of this byte buffer.
Returns
- A string represents the state of this byte buffer.
public
static
ByteBuffer
wrap(byte[] array)
Creates a new byte buffer by wrapping the given byte array.
Calling this method has the same effect as
wrap(array, 0, array.length)
.
Parameters
array
| The byte array which the new buffer will be based on |
public
static
ByteBuffer
wrap(byte[] array, int start, int len)
Creates new a byte buffer by wrapping the given byte array.
The new buffer's position will be start
, limit will be
start + len
, capacity will be the length of the array.
Parameters
array
| The byte array which the new buffer will be based on |
start
| The start index, must be no less than zero and no greater than
array.length |
len
| The length, must be no less than zero and no greater than
array.length - start |