Android
java.nio
public abstract class

java.nio.DoubleBuffer

java.lang.Object
java.nio.Buffer
java.nio.DoubleBuffer Comparable<T>

A buffer of doubles.

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

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

Summary

Public Methods

      static    DoubleBuffer  allocate(int capacity)
Creates a double buffer based on a new allocated double array.
    final      double[]  array()
Returns the double array which this buffer is based on, if there's one.
    final      int  arrayOffset()
Returns the offset of the double array which this buffer is based on, if there's one.
abstract          DoubleBuffer  asReadOnlyBuffer()
Returns a readonly buffer that shares content with this buffer.
abstract          DoubleBuffer  compact()
Compacts this double buffer.
          int  compareTo(DoubleBuffer otherBuffer)
Compare the remaining doubles of this buffer to another double buffer's remaining doubles.
abstract          DoubleBuffer  duplicate()
Returns a duplicated buffer that shares content with this buffer.
          boolean  equals(Object other)
Tests whether this double buffer equals to another object.
abstract          double  get()
Returns the double at the current position and increase the position by 1.
abstract          double  get(int index)
Returns a double at the specified index, and the position is not changed.
          DoubleBuffer  get(double[] dest, int off, int len)
Reads doubles from the current position into the specified double array, starting from the specified offset, and increase the position by the number of doubles read.
          DoubleBuffer  get(double[] dest)
Reads doubles from the current position into the specified double array and increase the position by the number of doubles read.
    final      boolean  hasArray()
Returns whether this buffer is based on a double array and is read/write.
          int  hashCode()
Hash code is calculated from the remaining doubles.
abstract          boolean  isDirect()
Returns true if this buffer is direct.
abstract          ByteOrder  order()
Returns the byte order used by this buffer when converting doubles from/to bytes.
    final      DoubleBuffer  put(double[] src)
Writes doubles in the given double array to the current position and increase the position by the number of doubles written.
          DoubleBuffer  put(DoubleBuffer src)
Writes all the remaining doubles of the src double buffer to this buffer's current position, and increase both buffers' position by the number of doubles copied.
abstract          DoubleBuffer  put(int index, double d)
Write a double to the specified index of this buffer and the position is not changed.
abstract          DoubleBuffer  put(double d)
Writes the given double to the current position and increase the position by 1.
          DoubleBuffer  put(double[] src, int off, int len)
Writes doubles in the given double array, starting from the specified offset, to the current position and increase the position by the number of doubles written.
abstract          DoubleBuffer  slice()
Returns a sliced buffer that shares content with this buffer.
          String  toString()
Returns a string represents the state of this double buffer.
      static    DoubleBuffer  wrap(double[] array, int start, int len)
Creates new a double buffer by wrapping the given double array.
      static    DoubleBuffer  wrap(double[] array)
Creates a new double buffer by wrapping the given double array.
Methods inherited from class java.nio.Buffer
Methods inherited from class java.lang.Object
Methods inherited from interface java.lang.Comparable

Details

Public Methods

public static DoubleBuffer allocate(int capacity)

Creates a double buffer based on a new allocated double array.

Parameters

capacity The capacity of the new buffer

Returns

  • The created double buffer

Throws

IllegalArgumentException If capacity is less than zero

public final double[] array()

Returns the double array which this buffer is based on, if there's one.

Returns

  • The double array which this buffer is based on

Throws

ReadOnlyBufferException If this buffer is based on an array, but it is readonly
UnsupportedOperationException If this buffer is not based on an array

public final int arrayOffset()

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

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

Returns

  • The offset of the double array which this buffer is based on

Throws

ReadOnlyBufferException If this buffer is based on an array, but it is readonly
UnsupportedOperationException If this buffer is not based on an array

public abstract DoubleBuffer asReadOnlyBuffer()

Returns a readonly buffer that shares content with this buffer.

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

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

Returns

  • A readonly version of this buffer.

public abstract DoubleBuffer compact()

Compacts this double buffer.

The remaining doubles 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

public int compareTo(DoubleBuffer otherBuffer)

Compare the remaining doubles of this buffer to another double buffer's remaining doubles.

Parameters

otherBuffer Another double 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 double buffer

public abstract DoubleBuffer duplicate()

Returns a duplicated buffer that shares content with this buffer.

The duplicated buffer's position, limit, capacity and mark are the same as this buffer. The duplicated buffer's readonly property and byte order are same as this buffer too.

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

Returns

  • A duplicated buffer that shares content with this buffer.

public boolean equals(Object other)

Tests whether this double buffer equals to another object.

If other is not a double buffer, then false is returned.

Two double buffers are equals if, and only if, their remaining doubles are exactly the same. Position, limit, capacity and mark are not considered.

Parameters

other the object to be compared against

Returns

  • Whether this double buffer equals to another object.

public abstract double get()

Returns the double at the current position and increase the position by 1.

Returns

  • The double at the current position.

Throws

BufferUnderflowException If the position is equal or greater than limit

public abstract double get(int index)

Returns a double at the specified index, and the position is not changed.

Parameters

index The index, must be no less than zero and less than limit

Returns

  • A double at the specified index.

Throws

IndexOutOfBoundsException If index is invalid

public DoubleBuffer get(double[] dest, int off, int len)

Reads doubles from the current position into the specified double array, starting from the specified offset, and increase the position by the number of doubles read.

Parameters

dest The target double array
off The offset of the double array, must be no less than zero and no greater than dest.length
len The number of doubles to read, must be no less than zero and no greater than dest.length - off

Returns

  • This buffer

Throws

IndexOutOfBoundsException If either off or len is invalid
BufferUnderflowException If len is greater than remaining()

public DoubleBuffer get(double[] dest)

Reads doubles from the current position into the specified double array and increase the position by the number of doubles read.

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

Parameters

dest The destination double array

Returns

  • This buffer

Throws

BufferUnderflowException if dest.length is greater than remaining()

public final boolean hasArray()

Returns whether this buffer is based on a double array and is read/write.

If this buffer is readonly, then false is returned.

Returns

  • Whether this buffer is based on a double array and is read/write.

public int hashCode()

Hash code is calculated from the remaining doubles.

Position, limit, capacity and mark don't affect the hash code.

Returns

  • The hash code calculated from the remaining doubles.

public abstract boolean isDirect()

Returns true if this buffer is direct.

A direct buffer will try its best to take advantage of native memory APIs and it may not stay in java heap, thus not affected by GC.

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

Returns

  • True if this buffer is direct.

public abstract ByteOrder order()

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

public final DoubleBuffer put(double[] src)

Writes doubles in the given double array to the current position and increase the position by the number of doubles written.

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

Parameters

src The source double 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

public DoubleBuffer put(DoubleBuffer src)

Writes all the remaining doubles of the src double buffer to this buffer's current position, and increase both buffers' position by the number of doubles copied.

Parameters

src The source double 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

public abstract DoubleBuffer put(int index, double d)

Write a double to the specified index of this buffer and the position is not changed.

Parameters

index The index, must be no less than zero and less than the limit
d The double to write

Returns

  • This buffer

Throws

IndexOutOfBoundsException If index is invalid
ReadOnlyBufferException If no changes may be made to the contents of this buffer

public abstract DoubleBuffer put(double d)

Writes the given double to the current position and increase the position by 1.

Parameters

d The double 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

public DoubleBuffer put(double[] src, int off, int len)

Writes doubles in the given double array, starting from the specified offset, to the current position and increase the position by the number of doubles written.

Parameters

src The source double array
off The offset of double array, must be no less than zero and no greater than src.length
len The number of doubles to write, must be no less than zero and no greater than src.length - off

Returns

  • This buffer

Throws

BufferOverflowException If remaining() is less than len
IndexOutOfBoundsException If either off or len is invalid
ReadOnlyBufferException If no changes may be made to the contents of this buffer

public abstract DoubleBuffer slice()

Returns a sliced buffer that shares content with this buffer.

The sliced buffer's capacity will be this buffer's remaining(), and its zero position will correspond to this buffer's current position. The new buffer's position will be 0, limit will be its capacity, and its mark is unset. The new buffer's readonly property and byte order are same as this buffer.

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

Returns

  • A sliced buffer that shares content with this buffer.

public String toString()

Returns a string represents the state of this double buffer.

Returns

  • A string represents the state of this double buffer.

public static DoubleBuffer wrap(double[] array, int start, int len)

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

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

Parameters

array The double array which the new buffer will be based on
start The start index, must be no less than zero and no greater than array.length
len The length, must be no less than zero and no greater than array.length - start

Returns

  • The created double buffer

Throws

IndexOutOfBoundsException If either start or len is invalid

public static DoubleBuffer wrap(double[] array)

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

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

Parameters

array The double array which the new buffer will be based on

Returns

  • The created double buffer
Copyright 2007 Google Inc. Build 0.9_r1-98467 - 14 Aug 2008 18:56