Package java.nio

Class FloatBuffer

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

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

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

  • Method Summary

    Modifier and Type Method Description
    static FloatBuffer allocate​(int capacity)
    Creates a float buffer based on a newly allocated float array.
    float[] 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 FloatBuffer asReadOnlyBuffer()
    Returns a read-only buffer that shares its content with this buffer.
    abstract FloatBuffer compact()
    Compacts this float buffer.
    int compareTo​(FloatBuffer otherBuffer)
    Compare the remaining floats of this buffer to another float buffer's remaining floats.
    abstract FloatBuffer duplicate()
    Returns a duplicated buffer that shares its content with this buffer.
    boolean equals​(Object other)
    Checks whether this float buffer is equal to another object.
    abstract float get()
    Returns the float at the current position and increases the position by 1.
    FloatBuffer get​(float[] dst)
    Reads floats from the current position into the specified float array and increases the position by the number of floats read.
    FloatBuffer get​(float[] dst, int dstOffset, int floatCount)
    Reads floats from the current position into the specified float array, starting from the specified offset, and increases the position by the number of floats read.
    abstract float get​(int index)
    Returns a float at the specified index; the position is not changed.
    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 floats from/to bytes.
    abstract FloatBuffer put​(float f)
    Writes the given float to the current position and increases the position by 1.
    FloatBuffer put​(float[] src)
    Writes floats from the given float array to the current position and increases the position by the number of floats written.
    FloatBuffer put​(float[] src, int srcOffset, int floatCount)
    Writes floats from the given float array, starting from the specified offset, to the current position and increases the position by the number of floats written.
    abstract FloatBuffer put​(int index, float f)
    Writes a float to the specified index of this buffer; the position is not changed.
    FloatBuffer put​(FloatBuffer src)
    Writes all the remaining floats of the src float buffer to this buffer's current position, and increases both buffers' position by the number of floats copied.
    abstract FloatBuffer slice()
    Returns a sliced buffer that shares its content with this buffer.
    static FloatBuffer wrap​(float[] array)
    Creates a new float buffer by wrapping the given float array.
    static FloatBuffer wrap​(float[] array, int start, int floatCount)
    Creates a new float buffer by wrapping the given float 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 FloatBuffer allocate​(int capacity)
      Creates a float buffer based on a newly allocated float array.
      Parameters:
      capacity - the capacity of the new buffer.
      Returns:
      the created float buffer.
      Throws:
      IllegalArgumentException - if capacity is less than zero.

    • wrap

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

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

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

    • wrap

      public static FloatBuffer wrap​(float[] array, int start, int floatCount)
      Creates a new float buffer by wrapping the given float array.

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

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

    • array

      public final float[] 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 FloatBuffer 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.

    • compact

      public abstract FloatBuffer compact()
      Compacts this float buffer.

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

    • compareTo

      public int compareTo​(FloatBuffer otherBuffer)
      Compare the remaining floats of this buffer to another float buffer's remaining floats.
      Specified by:
      compareTo in interface Comparable<FloatBuffer>
      Parameters:
      otherBuffer - another float 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 float buffer.

    • duplicate

      public abstract FloatBuffer 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 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 float buffer is equal to another object. If other is not a FloatBuffer then false is returned.

      Two float buffers are equal if their remaining floats are equal. Position, limit, capacity and mark are not considered.

      This method considers two floats a and b to be equal if a == b or if a and b are both NaN. Unlike Float.equals(java.lang.Object), this method considers -0.0 and +0.0 to be equal.

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

    • get

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

    • get

      public FloatBuffer get​(float[] dst)
      Reads floats from the current position into the specified float array and increases the position by the number of floats read.

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

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

    • get

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

    • get

      public abstract float get​(int index)
      Returns a float at the specified index; the position is not changed.
      Parameters:
      index - the index, must not be negative and less than limit.
      Returns:
      a float 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 floats.
      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 float 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 floats 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 floats from/to bytes.

    • put

      public abstract FloatBuffer put​(float f)
      Writes the given float to the current position and increases the position by 1.
      Parameters:
      f - the float 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 FloatBuffer put​(float[] src)
      Writes floats from the given float array to the current position and increases the position by the number of floats written.

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

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

    • put

      public FloatBuffer put​(FloatBuffer src)
      Writes all the remaining floats of the src float buffer to this buffer's current position, and increases both buffers' position by the number of floats copied.
      Parameters:
      src - the source float 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 FloatBuffer put​(int index, float f)
      Writes a float 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.
      f - the float 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 FloatBuffer 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.