Package java.nio

Class LongBuffer

java.lang.Object
java.nio.Buffer
java.nio.LongBuffer
All Implemented Interfaces:
Comparable<LongBuffer>
public abstract class LongBuffer
extends Buffer
implements Comparable<LongBuffer>
A buffer of longs.

A long buffer can be created in either of the following ways:

  • Allocate a new long array and create a buffer based on it;
  • Wrap an existing long array to create a new buffer;
  • Use ByteBuffer.asLongBuffer to create a long buffer based on a byte buffer.

  • Method Summary

    Modifier and Type Method Description
    static LongBuffer allocate​(int capacity)
    Creates a long buffer based on a newly allocated long array.
    long[] array()
    Returns the array that backs this buffer (optional operation).
    int arrayOffset()
    Returns the offset into the array returned by array of the first element of the buffer (optional operation).
    abstract LongBuffer asReadOnlyBuffer()
    Returns a read-only buffer that shares its content with this buffer.
    abstract LongBuffer compact()
    Compacts this long buffer.
    int compareTo​(LongBuffer otherBuffer)
    Compare the remaining longs of this buffer to another long buffer's remaining longs.
    abstract LongBuffer duplicate()
    Returns a duplicated buffer that shares its content with this buffer.
    boolean equals​(Object other)
    Checks whether this long buffer is equal to another object.
    abstract long get()
    Returns the long at the current position and increase the position by 1.
    abstract long get​(int index)
    Returns the long at the specified index; the position is not changed.
    LongBuffer get​(long[] dst)
    Reads longs from the current position into the specified long array and increases the position by the number of longs read.
    LongBuffer get​(long[] dst, int dstOffset, int longCount)
    Reads longs from the current position into the specified long array, starting from the specified offset, and increase the position by the number of longs read.
    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.
    abstract ByteOrder order()
    Returns the byte order used by this buffer when converting longs from/to bytes.
    abstract LongBuffer put​(int index, long l)
    Writes a long to the specified index of this buffer; the position is not changed.
    abstract LongBuffer put​(long l)
    Writes the given long to the current position and increases the position by 1.
    LongBuffer put​(long[] src)
    Writes longs from the given long array to the current position and increases the position by the number of longs written.
    LongBuffer put​(long[] src, int srcOffset, int longCount)
    Writes longs from the given long array, starting from the specified offset, to the current position and increases the position by the number of longs written.
    LongBuffer put​(LongBuffer src)
    Writes all the remaining longs of the src long buffer to this buffer's current position, and increases both buffers' position by the number of longs copied.
    abstract LongBuffer slice()
    Returns a sliced buffer that shares its content with this buffer.
    static LongBuffer wrap​(long[] array)
    Creates a new long buffer by wrapping the given long array.
    static LongBuffer wrap​(long[] array, int start, int longCount)
    Creates a new long buffer by wrapping the given long array.

    Methods inherited from class java.nio.Buffer

    capacity, clear, flip, hasRemaining, isReadOnly, limit, limit, mark, position, position, remaining, reset, rewind, toString

    Methods inherited from class java.lang.Object

    clone, finalize, getClass, notify, notifyAll, wait, wait, wait

  • Method Details

    • allocate

      public static LongBuffer allocate​(int capacity)
      Creates a long buffer based on a newly allocated long array.
      Parameters:
      capacity - the capacity of the new buffer.
      Returns:
      the created long buffer.
      Throws:
      IllegalArgumentException - if capacity is less than zero.

    • wrap

      public static LongBuffer wrap​(long[] array)
      Creates a new long buffer by wrapping the given long array.

      Calling this method has the same effect as wrap(array, 0, array.length).

      Parameters:
      array - the long array which the new buffer will be based on.
      Returns:
      the created long buffer.

    • wrap

      public static LongBuffer wrap​(long[] array, int start, int longCount)
      Creates a new long buffer by wrapping the given long array.

      The new buffer's position will be start, limit will be start + longCount, capacity will be the length of the array.

      Parameters:
      array - the long array which the new buffer will be based on.
      start - the start index, must not be negative and not greater than array.length.
      longCount - the length, must not be negative and not greater than array.length - start.
      Returns:
      the created long buffer.
      Throws:
      IndexOutOfBoundsException - if either start or longCount is invalid.

    • array

      public final long[] array()
      Description copied from class: Buffer
      Returns the array that backs this buffer (optional operation). The returned value is the actual array, not a copy, so modifications to the array write through to the buffer.

      Subclasses should override this method with a covariant return type to provide the exact type of the array.

      Use hasArray to ensure this method won't throw. (A separate call to isReadOnly is not necessary.)

      Specified by:
      array in class Buffer
      Returns:
      the array

    • arrayOffset

      public final int arrayOffset()
      Description copied from class: Buffer
      Returns the offset into the array returned by array of the first element of the buffer (optional operation). The backing array (if there is one) is not necessarily the same size as the buffer, and position 0 in the buffer is not necessarily the 0th element in the array. Use buffer.array()[offset + buffer.arrayOffset() to access element offset in buffer.

      Use hasArray to ensure this method won't throw. (A separate call to isReadOnly is not necessary.)

      Specified by:
      arrayOffset in class Buffer
      Returns:
      the offset

    • asReadOnlyBuffer

      public abstract LongBuffer 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's.

      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.

    • compact

      public abstract LongBuffer compact()
      Compacts this long buffer.

      The remaining longs 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.

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

    • compareTo

      public int compareTo​(LongBuffer otherBuffer)
      Compare the remaining longs of this buffer to another long buffer's remaining longs.
      Specified by:
      compareTo in interface Comparable<LongBuffer>
      Parameters:
      otherBuffer - another long buffer.
      Returns:
      a negative value if this is less than otherBuffer; 0 if this equals to otherBuffer; a positive value if this is greater than otherBuffer
      Throws:
      ClassCastException - if otherBuffer is not a long buffer.

    • duplicate

      public abstract LongBuffer 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. The duplicated buffer's read-only property and byte order are same as this buffer's, too.

      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.

    • equals

      public boolean equals​(Object other)
      Checks whether this long buffer is equal to another object.

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

      Overrides:
      equals in class Object
      Parameters:
      other - the object to compare with this long buffer.
      Returns:
      true if this long buffer is equal to other, false otherwise.
      See Also:
      Object.hashCode()

    • get

      public abstract long get()
      Returns the long at the current position and increase the position by 1.
      Returns:
      the long at the current position.
      Throws:
      BufferUnderflowException - if the position is equal or greater than limit.

    • get

      public LongBuffer get​(long[] dst)
      Reads longs from the current position into the specified long array and increases the position by the number of longs read.

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

      Parameters:
      dst - the destination long array.
      Returns:
      this buffer.
      Throws:
      BufferUnderflowException - if dst.length is greater than remaining().

    • get

      public LongBuffer get​(long[] dst, int dstOffset, int longCount)
      Reads longs from the current position into the specified long array, starting from the specified offset, and increase the position by the number of longs read.
      Parameters:
      dst - the target long array.
      dstOffset - the offset of the long array, must not be negative and not greater than dst.length.
      longCount - the number of longs to read, must be no less than zero and not greater than dst.length - dstOffset.
      Returns:
      this buffer.
      Throws:
      IndexOutOfBoundsException - if either dstOffset or longCount is invalid.
      BufferUnderflowException - if longCount is greater than remaining().

    • get

      public abstract long get​(int index)
      Returns the long at the specified index; the position is not changed.
      Parameters:
      index - the index, must not be negative and less than limit.
      Returns:
      the long at the specified index.
      Throws:
      IndexOutOfBoundsException - if index is invalid.

    • hasArray

      public final boolean hasArray()
      Description copied from class: Buffer
      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.
      Specified by:
      hasArray in class Buffer

    • hashCode

      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.
      Overrides:
      hashCode in class Object
      Returns:
      the hash code calculated from the remaining longs.
      See Also:
      Object.equals(java.lang.Object)

    • isDirect

      public abstract boolean isDirect()
      Indicates whether this buffer is direct. A direct buffer will try its best to take advantage of native memory APIs and it may not stay in the Java heap, so it is not affected by garbage collection.

      A long buffer is direct if it is based on a byte buffer and the byte buffer is direct.

      Specified by:
      isDirect in class Buffer
      Returns:
      true if this buffer is direct, false otherwise.

    • order

      public abstract ByteOrder order()
      Returns the byte order used by this buffer when converting longs from/to bytes.

      If this buffer is not based on a byte buffer, then always return the platform's native byte order.

      Returns:
      the byte order used by this buffer when converting longs from/to bytes.

    • put

      public abstract LongBuffer put​(long l)
      Writes the given long to the current position and increases the position by 1.
      Parameters:
      l - the long to write.
      Returns:
      this buffer.
      Throws:
      BufferOverflowException - if position is equal or greater than limit.
      ReadOnlyBufferException - if no changes may be made to the contents of this buffer.

    • put

      public final LongBuffer put​(long[] src)
      Writes longs from the given long array to the current position and increases the position by the number of longs written.

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

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

    • put

      public LongBuffer put​(long[] src, int srcOffset, int longCount)
      Writes longs from the given long array, starting from the specified offset, to the current position and increases the position by the number of longs written.
      Parameters:
      src - the source long array.
      srcOffset - the offset of long array, must not be negative and not greater than src.length.
      longCount - the number of longs to write, must be no less than zero and not greater than src.length - srcOffset.
      Returns:
      this buffer.
      Throws:
      BufferOverflowException - if remaining() is less than longCount.
      IndexOutOfBoundsException - if either srcOffset or longCount is invalid.
      ReadOnlyBufferException - if no changes may be made to the contents of this buffer.

    • put

      public LongBuffer put​(LongBuffer src)
      Writes all the remaining longs of the src long buffer to this buffer's current position, and increases both buffers' position by the number of longs copied.
      Parameters:
      src - the source long buffer.
      Returns:
      this buffer.
      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.

    • put

      public abstract LongBuffer put​(int index, long l)
      Writes a long to the specified index of this buffer; the position is not changed.
      Parameters:
      index - the index, must not be negative and less than the limit.
      l - the long to write.
      Returns:
      this buffer.
      Throws:
      IndexOutOfBoundsException - if index is invalid.
      ReadOnlyBufferException - if no changes may be made to the contents of this buffer.

    • slice

      public abstract LongBuffer slice()
      Returns a sliced buffer that shares its 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 cleared. The new buffer's read-only property and byte order are 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.