ByteBuffer - JRE Emulation | JRE Emulation
public abstract class

ByteBuffer

extends Buffer
implements Comparable<ByteBuffer>
java.lang.Object
   ↳ java.nio.Buffer
     ↳ java.nio.ByteBuffer
Known Direct Subclasses

Class Overview

A buffer for bytes.

A byte buffer can be created in either one 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.

Summary

Public Methods
static ByteBuffer allocate(int capacity)
Creates a byte buffer based on a newly allocated byte array.
static ByteBuffer allocateDirect(int capacity)
Creates a direct byte buffer based on a newly allocated memory block.
final byte[] array()
Returns the byte array which this buffer is based on, if there is one.
final int arrayOffset()
Returns the offset of the byte array which this buffer is based on, if there is one.
abstract CharBuffer asCharBuffer()
Returns a char buffer which is based on the remaining content of this byte buffer.
abstract DoubleBuffer asDoubleBuffer()
Returns a double buffer which is based on the remaining content of this byte buffer.
abstract FloatBuffer asFloatBuffer()
Returns a float buffer which is based on the remaining content of this byte buffer.
abstract IntBuffer asIntBuffer()
Returns a int buffer which is based on the remaining content of this byte buffer.
abstract LongBuffer asLongBuffer()
Returns a long buffer which is based on the remaining content of this byte buffer.
abstract ByteBuffer asReadOnlyBuffer()
Returns a read-only buffer that shares its content with this buffer.
abstract ShortBuffer asShortBuffer()
Returns a short buffer which is based on the remaining content of this byte buffer.
abstract ByteBuffer compact()
Compacts this byte buffer.
int compareTo(ByteBuffer otherBuffer)
Compares the remaining bytes of this buffer to another byte buffer's remaining bytes.
abstract ByteBuffer duplicate()
Returns a duplicated buffer that shares its content with this buffer.
boolean equals(Object other)
Checks whether this byte buffer is equal to another object.
abstract byte get()
Returns the byte at the current position and increases the position by 1.
ByteBuffer get(byte[] dst, int dstOffset, int byteCount)
Reads bytes from the current position into the specified byte array, starting at the specified offset, and increases the position by the number of bytes read.
abstract byte get(int index)
Returns the byte at the specified index and does not change the position.
ByteBuffer get(byte[] dst)
Reads bytes from the current position into the specified byte array and increases the position by the number of bytes read.
abstract char getChar()
Returns the char at the current position and increases the position by 2.
abstract char getChar(int index)
Returns the char at the specified index.
abstract double getDouble(int index)
Returns the double at the specified index.
abstract double getDouble()
Returns the double at the current position and increases the position by 8.
abstract float getFloat()
Returns the float at the current position and increases the position by 4.
abstract float getFloat(int index)
Returns the float at the specified index.
abstract int getInt(int index)
Returns the int at the specified index.
abstract int getInt()
Returns the int at the current position and increases the position by 4.
abstract long getLong(int index)
Returns the long at the specified index.
abstract long getLong()
Returns the long at the current position and increases the position by 8.
abstract short getShort(int index)
Returns the short at the specified index.
abstract short getShort()
Returns the short at the current position and increases the position by 2.
final boolean hasArray()
Returns true if array and arrayOffset won't throw.
int hashCode()
Calculates this buffer's hash code from the remaining chars.
abstract boolean isDirect()
Indicates whether this buffer is direct.
final ByteOrder order()
Returns the byte order used by this buffer when converting bytes from/to other primitive types.
final ByteBuffer order(ByteOrder byteOrder)
Sets the byte order of this buffer.
final ByteBuffer put(byte[] src)
Writes bytes in the given byte array to the current position and increases the position by the number of bytes written.
abstract ByteBuffer put(byte b)
Writes the given byte to the current position and increases the position by 1.
ByteBuffer put(byte[] src, int srcOffset, int byteCount)
Writes bytes in the given byte array, starting from the specified offset, to the current position and increases the position by the number of bytes written.
abstract ByteBuffer put(int index, byte b)
Write a byte to the specified index of this buffer without changing the position.
ByteBuffer put(ByteBuffer src)
Writes all the remaining bytes of the src byte buffer to this buffer's current position, and increases both buffers' position by the number of bytes copied.
abstract ByteBuffer putChar(int index, char value)
Writes the given char to the specified index of this buffer.
abstract ByteBuffer putChar(char value)
Writes the given char to the current position and increases the position by 2.
abstract ByteBuffer putDouble(double value)
Writes the given double to the current position and increases the position by 8.
abstract ByteBuffer putDouble(int index, double value)
Writes the given double to the specified index of this buffer.
abstract ByteBuffer putFloat(int index, float value)
Writes the given float to the specified index of this buffer.
abstract ByteBuffer putFloat(float value)
Writes the given float to the current position and increases the position by 4.
abstract ByteBuffer putInt(int index, int value)
Writes the given int to the specified index of this buffer.
abstract ByteBuffer putInt(int value)
Writes the given int to the current position and increases the position by 4.
abstract ByteBuffer putLong(long value)
Writes the given long to the current position and increases the position by 8.
abstract ByteBuffer putLong(int index, long value)
Writes the given long to the specified index of this buffer.
abstract ByteBuffer putShort(short value)
Writes the given short to the current position and increases the position by 2.
abstract ByteBuffer putShort(int index, short value)
Writes the given short to the specified index of this buffer.
abstract ByteBuffer slice()
Returns a sliced buffer that shares its content with this buffer.
static ByteBuffer wrap(byte[] array)
Creates a new byte buffer by wrapping the given byte array.
static ByteBuffer wrap(byte[] array, int start, int byteCount)
Creates a new byte buffer by wrapping the given byte array.
Inherited Methods
[Expand]
From class java.nio.Buffer
From class java.lang.Object
From interface java.lang.Comparable

Public Methods

public static ByteBuffer allocate (int capacity)

Creates a byte buffer based on a newly allocated byte array.

Parameters
capacity the capacity of the new buffer
Returns
  • the created byte buffer.
Throws
IllegalArgumentException if capacity < 0.

public static ByteBuffer allocateDirect (int capacity)

Creates a direct byte buffer based on a newly allocated memory block.

Parameters
capacity the capacity of the new buffer
Returns
  • the created byte buffer.
Throws
IllegalArgumentException if capacity < 0.

public final byte[] array ()

Returns the byte array which this buffer is based on, if there is one.

Returns
  • the byte array which this buffer is based on.
Throws
ReadOnlyBufferException if this buffer is based on a read-only array.
UnsupportedOperationException if this buffer is not based on an array.

public final int arrayOffset ()

Returns the offset of the byte array which this buffer is based on, if there is one.

The offset is the index of the array which corresponds to the zero position of the buffer.

Returns
  • the offset of the byte array which this buffer is based on.
Throws
ReadOnlyBufferException if this buffer is based on a read-only array.
UnsupportedOperationException if this buffer is not based on an array.

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 read-only property and byte order are the same as this buffer's. The new buffer is direct if this byte buffer is direct.

The new buffer shares its content with this buffer, which means either buffer's change of content will be visible to the other. The two buffers' position, limit and mark are independent.

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 eight, and its mark is not set. The new buffer's read-only property and byte order are the same as this buffer's. The new buffer is direct if this byte buffer is direct.

The new buffer shares its content with this buffer, which means either buffer's change of content will be visible to the other. The two buffers' position, limit and mark are independent.

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 four, and its mark is not set. The new buffer's read-only property and byte order are the same as this buffer's. The new buffer is direct if this byte buffer is direct.

The new buffer shares its content with this buffer, which means either buffer's change of content will be visible to the other. The two buffers' position, limit and mark are independent.

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 four, and its mark is not set. The new buffer's read-only property and byte order are the same as this buffer's. The new buffer is direct if this byte buffer is direct.

The new buffer shares its content with this buffer, which means either buffer's change of content will be visible to the other. The two buffers' position, limit and mark are independent.

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 eight, and its mark is not set. The new buffer's read-only property and byte order are the same as this buffer's. The new buffer is direct if this byte buffer is direct.

The new buffer shares its content with this buffer, which means either buffer's change of content will be visible to the other. The two buffers' position, limit and mark are independent.

public abstract ByteBuffer asReadOnlyBuffer ()

Returns a read-only buffer that shares its content with this buffer.

The returned buffer is guaranteed to be a new instance, even if this buffer is read-only itself. The new buffer's position, limit, capacity and mark are the same as this buffer.

The new buffer shares its 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 read-only 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 read-only property and byte order are the same as this buffer's. The new buffer is direct if this byte buffer is direct.

The new buffer shares its content with this buffer, which means either buffer's change of content will be visible to the other. The two buffers' position, limit and mark are independent.

public abstract ByteBuffer compact ()

Compacts this byte buffer.

The remaining bytes will be moved to the head of the buffer, starting from position zero. Then the position is set to remaining(); the limit is set to capacity; the mark is cleared.

Returns
  • this
Throws
ReadOnlyBufferException if no changes may be made to the contents of this buffer.

public int compareTo (ByteBuffer otherBuffer)

Compares the remaining bytes of this buffer to another byte buffer's remaining bytes.

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.
Throws
ClassCastException if other is not a byte buffer.

public abstract ByteBuffer duplicate ()

Returns a duplicated buffer that shares its content with this buffer.

The duplicated buffer's position, limit, capacity and mark are the same as this buffer's. The duplicated buffer's read-only property is the same as this buffer's.

Note that in contrast to all non-byte buffers, byte order is not preserved in the duplicate, and is instead set to big-endian.

The new buffer shares its content with this buffer, which means either buffer's change of content will be visible to the other. The two buffers' position, limit and mark are independent.

public boolean equals (Object other)

Checks whether this byte buffer is equal to another object.

If other is not a byte buffer then false is returned. Two byte buffers are equal if and only if their remaining bytes are exactly the same. Position, limit, capacity and mark are not considered.

Parameters
other the object to compare with this byte buffer.
Returns
  • true if this byte buffer is equal to other, false otherwise.

public abstract byte get ()

Returns the byte at the current position and increases the position by 1.

Returns
  • the byte at the current position.
Throws
BufferUnderflowException if the position is equal or greater than limit.

public ByteBuffer get (byte[] dst, int dstOffset, int byteCount)

Reads bytes from the current position into the specified byte array, starting at the specified offset, and increases the position by the number of bytes read.

Parameters
dst the target byte array.
dstOffset the offset of the byte array, must not be negative and not greater than dst.length.
byteCount the number of bytes to read, must not be negative and not greater than dst.length - dstOffset
Returns
  • this
Throws
IndexOutOfBoundsException if dstOffset < 0 || byteCount < 0
BufferUnderflowException if byteCount > remaining()

public abstract byte get (int index)

Returns the byte at the specified index and does not change the position.

Parameters
index the index, must not be negative and less than limit.
Returns
  • the byte at the specified index.
Throws
IndexOutOfBoundsException if index is invalid.

public ByteBuffer get (byte[] dst)

Reads bytes from the current position into the specified byte array and increases the position by the number of bytes read.

Calling this method has the same effect as get(dst, 0, dst.length).

Parameters
dst the destination byte array.
Returns
  • this
Throws
BufferUnderflowException if dst.length is greater than remaining().

public abstract char getChar ()

Returns the char at the current position and increases the position by 2.

The 2 bytes starting at the current position are composed into a char according to the current byte order and returned.

Returns
  • the char at the current position.
Throws
BufferUnderflowException if the position is greater than limit - 2.

public abstract char getChar (int index)

Returns the char at the specified index.

The 2 bytes starting from the specified index are composed into a char according to the current byte order and returned. The position is not changed.

Parameters
index the index, must not be negative and equal or less than limit - 2.
Returns
  • the char at the specified index.
Throws
IndexOutOfBoundsException if index is invalid.

public abstract double getDouble (int index)

Returns the double at the specified index.

The 8 bytes starting at the specified index are composed into a double according to the current byte order and returned. The position is not changed.

Parameters
index the index, must not be negative and equal or less than limit - 8.
Returns
  • the double at the specified index.
Throws
IndexOutOfBoundsException if index is invalid.

public abstract double getDouble ()

Returns the double at the current position and increases the position by 8.

The 8 bytes starting from the current position are composed into a double according to the current byte order and returned.

Returns
  • the double at the current position.
Throws
BufferUnderflowException if the position is greater than limit - 8.

public abstract float getFloat ()

Returns the float at the current position and increases the position by 4.

The 4 bytes starting at the current position are composed into a float according to the current byte order and returned.

Returns
  • the float at the current position.
Throws
BufferUnderflowException if the position is greater than limit - 4.

public abstract float getFloat (int index)

Returns the float at the specified index.

The 4 bytes starting at the specified index are composed into a float according to the current byte order and returned. The position is not changed.

Parameters
index the index, must not be negative and equal or less than limit - 4.
Returns
  • the float at the specified index.
Throws
IndexOutOfBoundsException if index is invalid.

public abstract int getInt (int index)

Returns the int at the specified index.

The 4 bytes starting at the specified index are composed into a int according to the current byte order and returned. The position is not changed.

Parameters
index the index, must not be negative and equal or less than limit - 4.
Returns
  • the int at the specified index.
Throws
IndexOutOfBoundsException if index is invalid.

public abstract int getInt ()

Returns the int at the current position and increases the position by 4.

The 4 bytes starting at the current position are composed into a int according to the current byte order and returned.

Returns
  • the int at the current position.
Throws
BufferUnderflowException if the position is greater than limit - 4.

public abstract long getLong (int index)

Returns the long at the specified index.

The 8 bytes starting at the specified index are composed into a long according to the current byte order and returned. The position is not changed.

Parameters
index the index, must not be negative and equal or less than limit - 8.
Returns
  • the long at the specified index.
Throws
IndexOutOfBoundsException if index is invalid.

public abstract long getLong ()

Returns the long at the current position and increases the position by 8.

The 8 bytes starting at the current position are composed into a long according to the current byte order and returned.

Returns
  • the long at the current position.
Throws
BufferUnderflowException if the position is greater than limit - 8.

public abstract short getShort (int index)

Returns the short at the specified index.

The 2 bytes starting at the specified index are composed into a short according to the current byte order and returned. The position is not changed.

Parameters
index the index, must not be negative and equal or less than limit - 2.
Returns
  • the short at the specified index.
Throws
IndexOutOfBoundsException if index is invalid.

public abstract short getShort ()

Returns the short at the current position and increases the position by 2.

The 2 bytes starting at the current position are composed into a short according to the current byte order and returned.

Returns
  • the short at the current position.
Throws
BufferUnderflowException if the position is greater than limit - 2.

public final boolean hasArray ()

Returns true if array and arrayOffset won't throw. This method does not return true for buffers not backed by arrays because the other methods would throw UnsupportedOperationException, nor does it return true for buffers backed by read-only arrays, because the other methods would throw ReadOnlyBufferException.

public int hashCode ()

Calculates this buffer's hash code from the remaining chars. The position, limit, capacity and mark don't affect the hash code.

Returns
  • the hash code calculated from the remaining bytes.

public abstract boolean isDirect ()

Indicates whether this buffer is direct.

Returns
  • true if this buffer is direct, false otherwise.

public final ByteOrder order ()

Returns the byte order used by this buffer when converting bytes 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 bytes from/to other primitive types.

public final ByteBuffer order (ByteOrder byteOrder)

Sets the byte order of this buffer.

Parameters
byteOrder the byte order to set. If null then the order will be LITTLE_ENDIAN.
Returns
  • this
See Also

public final ByteBuffer put (byte[] src)

Writes bytes in the given byte array to the current position and increases the position by the number of bytes written.

Calling this method has the same effect as put(src, 0, src.length).

Parameters
src the source byte array.
Returns
  • this
Throws
BufferOverflowException if remaining() is less than src.length.
ReadOnlyBufferException if no changes may be made to the contents of this buffer.

public abstract ByteBuffer put (byte b)

Writes the given byte to the current position and increases the position by 1.

Parameters
b the byte to write.
Returns
  • this
Throws
BufferOverflowException if position is equal or greater than limit.
ReadOnlyBufferException if no changes may be made to the contents of this buffer.

public ByteBuffer put (byte[] src, int srcOffset, int byteCount)

Writes bytes in the given byte array, starting from the specified offset, to the current position and increases the position by the number of bytes written.

Parameters
src the source byte array.
srcOffset the offset of byte array, must not be negative and not greater than src.length.
byteCount the number of bytes to write, must not be negative and not greater than src.length - srcOffset.
Returns
  • this
Throws
BufferOverflowException if remaining() is less than byteCount.
IndexOutOfBoundsException if either srcOffset or byteCount is invalid.
ReadOnlyBufferException if no changes may be made to the contents of this buffer.

public abstract ByteBuffer put (int index, byte b)

Write a byte to the specified index of this buffer without changing the position.

Parameters
index the index, must not be negative and less than the limit.
b the byte to write.
Returns
  • this
Throws
IndexOutOfBoundsException if index is invalid.
ReadOnlyBufferException if no changes may be made to the contents of this buffer.

public ByteBuffer put (ByteBuffer src)

Writes all the remaining bytes of the src byte buffer to this buffer's current position, and increases both buffers' position by the number of bytes copied.

Parameters
src the source byte buffer.
Returns
  • this
Throws
BufferOverflowException if src.remaining() is greater than this buffer's remaining().
IllegalArgumentException if src is this buffer.
ReadOnlyBufferException if no changes may be made to the contents of this buffer.

public abstract ByteBuffer putChar (int index, char value)

Writes the given 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 not be negative and equal or less than limit - 2.
value the char to write.
Returns
  • this
Throws
IndexOutOfBoundsException if index is invalid.
ReadOnlyBufferException if no changes may be made to the contents of this buffer.

public abstract ByteBuffer putChar (char value)

Writes the given char to the current position and increases the position by 2.

The char is converted to bytes using the current byte order.

Parameters
value the char to write.
Returns
  • this
Throws
BufferOverflowException if position is greater than limit - 2.
ReadOnlyBufferException if no changes may be made to the contents of this buffer.

public abstract ByteBuffer putDouble (double value)

Writes the given double to the current position and increases the position by 8.

The double is converted to bytes using the current byte order.

Parameters
value the double to write.
Returns
  • this
Throws
BufferOverflowException if position is greater than limit - 8.
ReadOnlyBufferException if no changes may be made to the contents of this buffer.

public abstract ByteBuffer putDouble (int index, double value)

Writes the given 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 not be negative and equal or less than limit - 8.
value the double to write.
Returns
  • this
Throws
IndexOutOfBoundsException if index is invalid.
ReadOnlyBufferException if no changes may be made to the contents of this buffer.

public abstract ByteBuffer putFloat (int index, float value)

Writes the given 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 not be negative and equal or less than limit - 4.
value the float to write.
Returns
  • this
Throws
IndexOutOfBoundsException if index is invalid.
ReadOnlyBufferException if no changes may be made to the contents of this buffer.

public abstract ByteBuffer putFloat (float value)

Writes the given float to the current position and increases the position by 4.

The float is converted to bytes using the current byte order.

Parameters
value the float to write.
Returns
  • this
Throws
BufferOverflowException if position is greater than limit - 4.
ReadOnlyBufferException if no changes may be made to the contents of this buffer.

public abstract ByteBuffer putInt (int index, int value)

Writes the given 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 not be negative and equal or less than limit - 4.
value the int to write.
Returns
  • this
Throws
IndexOutOfBoundsException if index is invalid.
ReadOnlyBufferException if no changes may be made to the contents of this buffer.

public abstract ByteBuffer putInt (int value)

Writes the given int to the current position and increases the position by 4.

The int is converted to bytes using the current byte order.

Parameters
value the int to write.
Returns
  • this
Throws
BufferOverflowException if position is greater than limit - 4.
ReadOnlyBufferException if no changes may be made to the contents of this buffer.

public abstract ByteBuffer putLong (long value)

Writes the given long to the current position and increases the position by 8.

The long is converted to bytes using the current byte order.

Parameters
value the long to write.
Returns
  • this
Throws
BufferOverflowException if position is greater than limit - 8.
ReadOnlyBufferException if no changes may be made to the contents of this buffer.

public abstract ByteBuffer putLong (int index, long value)

Writes the given 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 not be negative and equal or less than limit - 8.
value the long to write.
Returns
  • this
Throws
IndexOutOfBoundsException if index is invalid.
ReadOnlyBufferException if no changes may be made to the contents of this buffer.

public abstract ByteBuffer putShort (short value)

Writes the given short to the current position and increases the position by 2.

The short is converted to bytes using the current byte order.

Parameters
value the short to write.
Returns
  • this
Throws
BufferOverflowException if position is greater than limit - 2.
ReadOnlyBufferException if no changes may be made to the contents of this buffer.

public abstract ByteBuffer putShort (int index, short value)

Writes the given 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 not be negative and equal or less than limit - 2.
value the short to write.
Returns
  • this
Throws
IndexOutOfBoundsException if index is invalid.
ReadOnlyBufferException if no changes may be made to the contents of this buffer.

public abstract ByteBuffer slice ()

Returns a sliced buffer that shares its content with this buffer.

The sliced buffer's capacity will be this buffer's remaining(), and it's 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 cleared. The new buffer's read-only property and byte order are the same as this buffer's.

The new buffer shares its content with this buffer, which means either buffer's change of content will be visible to the other. The two buffers' position, limit and mark are independent.

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
Returns
  • the created byte buffer.

public static ByteBuffer wrap (byte[] array, int start, int byteCount)

Creates a new byte buffer by wrapping the given byte array.

The new buffer's position will be start, limit will be start + byteCount, 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 not be negative and not greater than array.length.
byteCount the length, must not be negative and not greater than array.length - start.
Returns
  • the created byte buffer.
Throws
IndexOutOfBoundsException if either start or byteCount is invalid.