Class ByteBuffer

Method Details

• 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 - The new buffer's capacity, in bytes

  Returns:

  The new byte buffer

  Throws:

  IllegalArgumentException - If the capacity is a negative integer

• 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 - The new buffer's capacity, in bytes

  Returns:

  The new byte buffer

  Throws:

  IllegalArgumentException - If the capacity is a negative integer

• 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 - The array that will back the new buffer

  offset - The offset of the subarray to be used; must be non-negative and no larger than array.length. The new buffer's position will be set to this value.

  length - The length of the subarray to be used; must be non-negative and no larger than array.length - offset. The new buffer's limit will be set to offset + length.

  Returns:

  The new byte buffer

  Throws:

  IndexOutOfBoundsException - If the preconditions on the offset and length parameters do not hold

• 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 - The array that will back this buffer

  Returns:

  The new byte 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.

  Specified by:

  slice in class Buffer

  Returns:

  The new byte buffer

  See Also:

  • alignedSlice(int)

• 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.

  Specified by:

  slice in class Buffer

  Parameters:

  index - The position in this buffer at which the content of the new buffer will start; must be non-negative and no larger than limit()

  length - The number of elements the new buffer will contain; must be non-negative and no larger than limit() - index

  Returns:

  The new buffer

  Throws:

  IndexOutOfBoundsException - If index is negative or greater than limit(), length is negative, or length > limit() - index

  Since:

  13

• 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.

  Specified by:

  duplicate in class Buffer

  Returns:

  The new byte 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:

  The new, read-only byte buffer

• get

  public abstract byte get()

  Relative get method. Reads the byte at this buffer's current position, and then increments the position.

  Returns:

  The byte at the buffer's current position

  Throws:

  BufferUnderflowException - If the buffer's current position is not smaller than its limit

• 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 - The byte to be written

  Returns:

  This buffer

  Throws:

  BufferOverflowException - If this buffer's current position is not smaller than its limit

  ReadOnlyBufferException - If this buffer is read-only

• get

  public abstract byte get(int index)

  Absolute get method. Reads the byte at the given index.

  Parameters:

  index - The index from which the byte will be read

  Returns:

  The byte at the given index

  Throws:

  IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit

• 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 - The index at which the byte will be written

  b - The byte value to be written

  Returns:

  This buffer

  Throws:

  IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit

  ReadOnlyBufferException - If this buffer is read-only

• 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

  Copy

      for (int i = off; i < off + len; i++)
          dst[i] = src.get();
  

  except that it first checks that there are sufficient bytes in this buffer and it is potentially much more efficient.

  Parameters:

  dst - The array into which bytes are to be written

  offset - The offset within the array of the first byte to be written; must be non-negative and no larger than dst.length

  length - The maximum number of bytes to be written to the given array; must be non-negative and no larger than dst.length - offset

  Returns:

  This buffer

  Throws:

  BufferUnderflowException - If there are fewer than length bytes remaining in this buffer

  IndexOutOfBoundsException - If the preconditions on the offset and length parameters do not hold

• 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

  Copy

      src.get(a, 0, a.length)
  

  Parameters:

  dst - The destination array

  Returns:

  This buffer

  Throws:

  BufferUnderflowException - If there are fewer than length bytes remaining in this buffer

• 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:

  Copy

      for (int i = offset, j = index; i < offset + length; i++, j++)
          dst[i] = src.get(j);
  

  Parameters:

  index - The index in this buffer from which the first byte will be read; must be non-negative and less than limit()

  dst - The destination array

  offset - The offset within the array of the first byte to be written; must be non-negative and less than dst.length

  length - 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:

  This buffer

  Throws:

  IndexOutOfBoundsException - If the preconditions on the index, offset, and length parameters do not hold

  Since:

  13

• 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:

  Copy

      src.get(index, dst, 0, dst.length)
  

  Parameters:

  index - The index in this buffer from which the first byte will be read; must be non-negative and less than limit()

  dst - The destination array

  Returns:

  This buffer

  Throws:

  IndexOutOfBoundsException - If index is negative, not smaller than limit(), or limit() - index < dst.length

  Since:

  13

• 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

  Copy

      while (src.hasRemaining())
          dst.put(src.get());
  

  except that it first checks that there is sufficient space in this buffer and it is potentially much more efficient. If this buffer and the source buffer share the same backing array or memory, then the result will be as if the source elements were first copied to an intermediate location before being written into this buffer.

  Parameters:

  src - The source buffer from which bytes are to be read; must not be this buffer

  Returns:

  This buffer

  Throws:

  BufferOverflowException - If there is insufficient space in this buffer for the remaining bytes in the source buffer

  IllegalArgumentException - If the source buffer is this buffer

  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

  Copy

      for (int i = offset, j = index; i < offset + length; i++, j++)
          dst.put(j, src.get(i));
  

  except that it first checks the consistency of the supplied parameters and it is potentially much more efficient. If this buffer and the source buffer share the same backing array or memory, then the result will be as if the source elements were first copied to an intermediate location before being written into this buffer.

  Parameters:

  index - The index in this buffer at which the first byte will be written; must be non-negative and less than limit()

  src - The buffer from which bytes are to be read

  offset - The index within the source buffer of the first byte to be read; must be non-negative and less than src.limit()

  length - 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:

  This buffer

  Throws:

  IndexOutOfBoundsException - If the preconditions on the index, offset, and length parameters do not hold

  ReadOnlyBufferException - If this buffer is read-only

  Since:

  16

• 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

  Copy

      for (int i = off; i < off + len; i++)
          dst.put(src[i]);
  

  except that it first checks that there is sufficient space in this buffer and it is potentially much more efficient.

  Parameters:

  src - The array from which bytes are to be read

  offset - The offset within the array of the first byte to be read; must be non-negative and no larger than src.length

  length - The number of bytes to be read from the given array; must be non-negative and no larger than src.length - offset

  Returns:

  This buffer

  Throws:

  BufferOverflowException - If there is insufficient space in this buffer

  IndexOutOfBoundsException - If the preconditions on the offset and length parameters do not hold

  ReadOnlyBufferException - If this buffer is read-only

• 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

  Copy

      dst.put(a, 0, a.length)
  

  Parameters:

  src - The source array

  Returns:

  This buffer

  Throws:

  BufferOverflowException - If there is insufficient space in this buffer

  ReadOnlyBufferException - If this buffer is read-only

• 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:

  Copy

      for (int i = offset, j = index; i < offset + length; i++, j++)
          dst.put(j, src[i]);
  

  Parameters:

  index - The index in this buffer at which the first byte will be written; must be non-negative and less than limit()

  src - The array from which bytes are to be read

  offset - The offset within the array of the first byte to be read; must be non-negative and less than src.length

  length - 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:

  This buffer

  Throws:

  IndexOutOfBoundsException - If the preconditions on the index, offset, and length parameters do not hold

  ReadOnlyBufferException - If this buffer is read-only

  Since:

  13

• 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:

  Copy

      dst.put(index, src, 0, src.length);
  

  Parameters:

  index - The index in this buffer at which the first byte will be written; must be non-negative and less than limit()

  src - The array from which bytes are to be read

  Returns:

  This buffer

  Throws:

  IndexOutOfBoundsException - If index is negative, not smaller than limit(), or limit() - index < src.length

  ReadOnlyBufferException - If this buffer is read-only

  Since:

  13

• 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.

  Specified by:

  hasArray in class Buffer

  Returns:

  true if, and only if, this buffer is backed by an array and is not read-only

• 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.

  Specified by:

  array in class Buffer

  Returns:

  The array that backs this buffer

  Throws:

  ReadOnlyBufferException - If this buffer is backed by an array but is read-only

  UnsupportedOperationException - If this buffer is not backed by an accessible array

• 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.

  Specified by:

  arrayOffset in class Buffer

  Returns:

  The offset within this buffer's array of the first element of the buffer

  Throws:

  ReadOnlyBufferException - If this buffer is backed by an array but is read-only

  UnsupportedOperationException - If this buffer is not backed by an accessible array

• position

  public ByteBuffer position(int newPosition)

  Sets this buffer's position. If the mark is defined and larger than the new position then it is discarded.

  Overrides:

  position in class Buffer

  Parameters:

  newPosition - The new position value; must be non-negative and no larger than the current limit

  Returns:

  This buffer

  Since:

  9

• limit

  public ByteBuffer 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.

  Overrides:

  limit in class Buffer

  Parameters:

  newLimit - The new limit value; must be non-negative and no larger than this buffer's capacity

  Returns:

  This buffer

  Since:

  9

• mark

  public ByteBuffer mark()

  Sets this buffer's mark at its position.

  Overrides:

  mark in class Buffer

  Returns:

  This buffer

  Since:

  9

• reset

  public ByteBuffer reset()

  Resets this buffer's position to the previously-marked position.

  Invoking this method neither changes nor discards the mark's value.

  Overrides:

  reset in class Buffer

  Returns:

  This buffer

  Since:

  9

• clear

  public ByteBuffer 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:

  Copy

      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.

  Overrides:

  clear in class Buffer

  Returns:

  This buffer

  Since:

  9

• flip

  public ByteBuffer 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:

  Copy

      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.

  Overrides:

  flip in class Buffer

  Returns:

  This buffer

  Since:

  9

• rewind

  public ByteBuffer 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:

  Copy

      out.write(buf);    // Write remaining data
      buf.rewind();      // Rewind buffer
      buf.get(array);    // Copy data into array
  

  Overrides:

  rewind in class Buffer

  Returns:

  This buffer

  Since:

  9

• 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:

  Copy

      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:

  This buffer

  Throws:

  ReadOnlyBufferException - If this buffer is read-only

• isDirect

  public abstract boolean isDirect()

  Tells whether or not this byte buffer is direct.

  Specified by:

  isDirect in class Buffer

  Returns:

  true if, and only if, this buffer is direct

• toString

  public String toString()

  Returns a string summarizing the state of this buffer.

  Overrides:

  toString in class Object

  Returns:

  A summary string

• 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.

  Overrides:

  hashCode in class Object

  Returns:

  The current hash code of this buffer

  See Also:

  • Object.equals(java.lang.Object)
  • System.identityHashCode(java.lang.Object)

• 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,

  1. They have the same element type,

  2. They have the same number of remaining elements, and

  3. 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.

  Overrides:

  equals in class Object

  Parameters:

  ob - The object to which this buffer is to be compared

  Returns:

  true if, and only if, this buffer is equal to the given object

  See Also:

  • Object.hashCode()
  • HashMap

• 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.

  Specified by:

  compareTo in interface Comparable<ByteBuffer>

  Parameters:

  that - the object to be compared.

  Returns:

  A negative integer, zero, or a positive integer as this buffer is less than, equal to, or greater than the given buffer

• 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 - The byte buffer to be tested for a mismatch with this buffer

  Returns:

  The relative index of the first mismatch between this and the given buffer, otherwise -1 if no mismatch.

  Since:

  11

• 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:

  This buffer's byte order

• order

  public final ByteBuffer order(ByteOrder bo)

  Modifies this buffer's byte order.

  Parameters:

  bo - The new byte order, either BIG_ENDIAN or LITTLE_ENDIAN

  Returns:

  This buffer

• 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

  Copy

      int value = alignmentOffset(index, unitSize)
  

  then the identities

  Copy

      alignmentOffset(index - value, unitSize) == 0, value <= index
  

  and

  Copy

      alignmentOffset(index + (unitSize - value), unitSize) == 0
  

  must hold.

  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 then 8.

  Parameters:

  index - The index to query for alignment offset, must be non-negative, no upper bounds check is performed

  unitSize - The unit size in bytes, must be a power of 2

  Returns:

  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.

  Since:

  9

  See Also:

  • alignedSlice(int)

• 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:

  Copy

      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 then 8.

  Parameters:

  unitSize - The unit size in bytes, must be a power of 2

  Returns:

  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.

  Since:

  9

  See Also:

  • alignmentOffset(int, int)
  • slice()

• 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:

  The char value at the buffer's current position

  Throws:

  BufferUnderflowException - If there are fewer than two bytes remaining in this buffer

• 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 - The char value to be written

  Returns:

  This buffer

  Throws:

  BufferOverflowException - If there are fewer than two bytes remaining in this buffer

  ReadOnlyBufferException - If this buffer is read-only

• 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 - The index from which the bytes will be read

  Returns:

  The char value at the given index

  Throws:

  IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit, minus one

• 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 - The index at which the bytes will be written

  value - The char value to be written

  Returns:

  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

• 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:

  A new char buffer

• 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:

  The short value at the buffer's current position

  Throws:

  BufferUnderflowException - If there are fewer than two bytes remaining in this buffer

• 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 - The short value to be written

  Returns:

  This buffer

  Throws:

  BufferOverflowException - If there are fewer than two bytes remaining in this buffer

  ReadOnlyBufferException - If this buffer is read-only

• 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 - The index from which the bytes will be read

  Returns:

  The short value at the given index

  Throws:

  IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit, minus one

• 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 - The index at which the bytes will be written

  value - The short value to be written

  Returns:

  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

• 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:

  A new short buffer

• 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:

  The int value at the buffer's current position

  Throws:

  BufferUnderflowException - If there are fewer than four bytes remaining in this buffer

• 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 - The int value to be written

  Returns:

  This buffer

  Throws:

  BufferOverflowException - If there are fewer than four bytes remaining in this buffer

  ReadOnlyBufferException - If this buffer is read-only

• 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 - The index from which the bytes will be read

  Returns:

  The int value at the given index

  Throws:

  IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit, minus three

• 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 - The index at which the bytes will be written

  value - The int value to be written

  Returns:

  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

• 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:

  A new int buffer

• 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:

  The long value at the buffer's current position

  Throws:

  BufferUnderflowException - If there are fewer than eight bytes remaining in this buffer

• 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 - The long value to be written

  Returns:

  This buffer

  Throws:

  BufferOverflowException - If there are fewer than eight bytes remaining in this buffer

  ReadOnlyBufferException - If this buffer is read-only

• 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 - The index from which the bytes will be read

  Returns:

  The long value at the given index

  Throws:

  IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit, minus seven

• 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 - The index at which the bytes will be written

  value - The long value to be written

  Returns:

  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

• 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:

  A new long 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:

  The float value at the buffer's current position

  Throws:

  BufferUnderflowException - If there are fewer than four bytes remaining in this buffer

• 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 - The float value to be written

  Returns:

  This buffer

  Throws:

  BufferOverflowException - If there are fewer than four bytes remaining in this buffer

  ReadOnlyBufferException - If this buffer is read-only

• 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 - The index from which the bytes will be read

  Returns:

  The float value at the given index

  Throws:

  IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit, minus three

• 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 - The index at which the bytes will be written

  value - The float value to be written

  Returns:

  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

• 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:

  A new float buffer

• 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:

  The double value at the buffer's current position

  Throws:

  BufferUnderflowException - If there are fewer than eight bytes remaining in this buffer

• 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 - The double value to be written

  Returns:

  This buffer

  Throws:

  BufferOverflowException - If there are fewer than eight bytes remaining in this buffer

  ReadOnlyBufferException - If this buffer is read-only

• 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 - The index from which the bytes will be read

  Returns:

  The double value at the given index

  Throws:

  IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit, minus seven

• 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 - The index at which the bytes will be written

  value - The double value to be written

  Returns:

  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

• 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:

  A new double buffer