Android APIs
public abstract class

DoubleBuffer

extends Buffer
implements Comparable<DoubleBuffer>
java.lang.Object
   ↳ java.nio.Buffer
     ↳ java.nio.DoubleBuffer

Class Overview

A buffer of doubles.

A double buffer can be created in either one 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 newly allocated double array.
final double[] array()
Returns the array that backs this buffer (optional operation).
final int arrayOffset()
Returns the offset into the array returned by array of the first element of the buffer (optional operation).
abstract DoubleBuffer asReadOnlyBuffer()
Returns a read-only buffer that shares its 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 its content with this buffer.
boolean equals(Object other)
Checks whether this double buffer is equal to another object.
abstract double get(int index)
Returns a double at the specified index; the position is not changed.
DoubleBuffer get(double[] dst, int dstOffset, int doubleCount)
Reads doubles from the current position into the specified double array, starting from the specified offset, and increases the position by the number of doubles read.
DoubleBuffer get(double[] dst)
Reads doubles from the current position into the specified double array and increases the position by the number of doubles read.
abstract double get()
Returns the double at the current position and increases the position by 1.
final boolean hasArray()
Returns true if array and arrayOffset won't throw.
int hashCode()
Calculates this buffer's hash code from the remaining chars.
abstract boolean isDirect()
Indicates whether this buffer is direct.
abstract ByteOrder order()
Returns the byte order used by this buffer when converting doubles from/to bytes.
DoubleBuffer put(double[] src, int srcOffset, int doubleCount)
Writes doubles from the given double array, starting from the specified offset, to the current position and increases 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 increases 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.
final DoubleBuffer put(double[] src)
Writes doubles from the given double array to the current position and increases the position by the number of doubles written.
abstract DoubleBuffer put(double d)
Writes the given double to the current position and increases the position by 1.
abstract DoubleBuffer slice()
Returns a sliced buffer that shares its content with this buffer.
static DoubleBuffer wrap(double[] array, int start, int doubleCount)
Creates a new double buffer by wrapping the given double array.
static DoubleBuffer wrap(double[] array)
Creates a new double buffer by wrapping the given double array.
[Expand]
Inherited Methods
From class java.nio.Buffer
From class java.lang.Object
From interface java.lang.Comparable

Public Methods

public static DoubleBuffer allocate (int capacity)

Added in API level 1

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

Parameters
capacity the capacity of the new buffer.
Returns
DoubleBuffer the created double buffer.
Throws
IllegalArgumentException if capacity is less than zero.

public final double[] array ()

Added in API level 1

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.)

Returns
double[] the array

public final int arrayOffset ()

Added in API level 1

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.)

Returns
int the offset

public abstract DoubleBuffer asReadOnlyBuffer ()

Added in API level 1

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

Returns
DoubleBuffer a read-only version of this buffer.

public abstract DoubleBuffer compact ()

Added in API level 1

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

public int compareTo (DoubleBuffer otherBuffer)

Added in API level 1

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

Parameters
otherBuffer another double buffer.
Returns
int 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 ()

Added in API level 1

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

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

Returns
DoubleBuffer

public boolean equals (Object other)

Added in API level 1

Checks whether this double buffer is equal to another object. If other is not a DoubleBuffer then false is returned.

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

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

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

public abstract double get (int index)

Added in API level 1

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

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

public DoubleBuffer get (double[] dst, int dstOffset, int doubleCount)

Added in API level 1

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

Parameters
dst the target double array.
dstOffset the offset of the double array, must not be negative and not greater than dst.length.
doubleCount the number of doubles to read, must be no less than zero and not greater than dst.length - dstOffset.
Returns
DoubleBuffer this buffer.
Throws
IndexOutOfBoundsException if either dstOffset or doubleCount is invalid.
BufferUnderflowException if doubleCount is greater than remaining().

public DoubleBuffer get (double[] dst)

Added in API level 1

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

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

Parameters
dst the destination double array.
Returns
DoubleBuffer this buffer.
Throws
BufferUnderflowException if dst.length is greater than remaining().

public abstract double get ()

Added in API level 1

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

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

public final boolean hasArray ()

Added in API level 1

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.

Returns
boolean

public int hashCode ()

Added in API level 1

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

Returns
int the hash code calculated from the remaining chars.

public abstract boolean isDirect ()

Added in API level 1

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

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

public abstract ByteOrder order ()

Added in API level 1

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 this always returns the platform's native byte order.

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

public DoubleBuffer put (double[] src, int srcOffset, int doubleCount)

Added in API level 1

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

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

public DoubleBuffer put (DoubleBuffer src)

Added in API level 1

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

Parameters
src the source double buffer.
Returns
DoubleBuffer 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)

Added in API level 1

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

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

public final DoubleBuffer put (double[] src)

Added in API level 1

Writes doubles from the given double array to the current position and increases 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
DoubleBuffer 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 abstract DoubleBuffer put (double d)

Added in API level 1

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

Parameters
d the double to write.
Returns
DoubleBuffer 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 abstract DoubleBuffer slice ()

Added in API level 1

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 the same as this buffer's.

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

Returns
DoubleBuffer

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

Added in API level 1

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

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

public static DoubleBuffer wrap (double[] array)

Added in API level 1

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
DoubleBuffer the created double buffer.