Java Doc for FloatBuffer.java in  » 6.0-JDK-Modules » j2me » java » nio » Java Source Code / Java DocumentationJava Source Code and Java Documentation

This class is provided as part of the JSR 239 NIO Buffer building block. It is a subset of the java.nio.FloatBuffer class in Java(TM) Standard Edition version 1.4.2. Differences are noted in bold italic. The class documentation may make reference to classes that are not present in the building block.

I/O channels, marking and resetting, and read-only buffers are not supported. Allocation of non-direct float buffers, compaction, and duplication are not supported. The following methods are omitted:

• FloatBuffer allocate(int capacity)
• FloatBuffer compact()
• FloatBuffer duplicate()
• Buffer mark()
• Buffer reset()
• boolean isReadOnly()
• FloatBuffer asReadOnlyBuffer()

This class defines four categories of operations upon float buffers:

• Absolute and relative FloatBuffer.get() get and FloatBuffer.put(float) put methods that read and write single floats;

• Relative FloatBuffer.get(float[]) bulk get methods that transfer contiguous sequences of floats from this buffer into an array;

• Relative FloatBuffer.put(float[]) bulk put methods that transfer contiguous sequences of floats from a float array or some other float buffer into this buffer; and

• Methods for compacting, duplicating, and FloatBuffer.sliceslicing a float buffer. JSR 239 does not support compacting and duplicating buffers.

Float buffers can be created either by allocation, which allocates space for the buffer's content, by FloatBuffer.wrap(float[])wrapping an existing float array into a buffer, or by creating a view of an existing byte buffer. JSR 239 supports allocation of ByteBuffers only.

Like a byte buffer, a float buffer is either direct or non-direct. A float buffer created via the wrap methods of this class will be non-direct. A float buffer created as a view of a byte buffer will be direct if, and only if, the byte buffer itself is direct. Whether or not a float buffer is direct may be determined by invoking the FloatBuffer.isDirect isDirect method.

Modifications to this buffer's content will cause the returned array's content to be modified, and vice versa.

Invoke the FloatBuffer.hasArray hasArray method before invoking this method in order to ensure that this buffer has an accessible backing array.

If this buffer is backed by an array then buffer position p corresponds to array index p + arrayOffset().

Invoke the FloatBuffer.hasArray hasArray method before invoking this method in order to ensure that this buffer has an accessible backing array.

Two float 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 float buffer is not equal to any other type of object.

This method transfers floats from this buffer into the given destination array.

This method transfers floats from this buffer into the given destination array.

If this method returns true then the FloatBuffer.array() array and FloatBuffer.arrayOffset() arrayOffset methods may safely be invoked.

The hash code of a float 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.

Writes the given float into this buffer at the current position, and then increments the position.

Writes the given float into this buffer at the given index.

This method transfers the floats remaining in the given source buffer into this buffer.

This method transfers floats into this buffer from the given source array.

This method transfers the entire content of the given source float array into this buffer.

The content of the new buffer will start at this buffer's current position.

The new buffer will be backed by the given float array; that is, modifications to the buffer will cause the array to be modified and vice versa.

The new buffer will be backed by the given float array; that is, modifications to the buffer will cause the array to be modified and vice versa.

Modifications to this buffer's content will cause the returned array's content to be modified, and vice versa.

Invoke the FloatBuffer.hasArray hasArray method before invoking this method in order to ensure that this buffer has an accessible backing array.

If this buffer is backed by an array then buffer position p corresponds to array index p + arrayOffset().

Invoke the FloatBuffer.hasArray hasArray method before invoking this method in order to ensure that this buffer has an accessible backing array.

Two float buffers are compared by comparing their sequences of remaining elements lexicographically, without regard to the starting position of each sequence within its corresponding buffer.

A float buffer is not comparable to any other type of object. A negative integer, zero, or a positive integer as this bufferis less than, equal to, or greater than the given buffer.
throws:
  ClassCastException - If the argument is not a float buffer.

Two float 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 float buffer is not equal to any other type of object.

This method transfers floats from this buffer into the given destination array. If there are fewer floats remaining in the buffer than are required to satisfy the request, that is, if length > remaining(), then no floats are transferred and a BufferUnderflowException is thrown.

Otherwise, this method copies length floats 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

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

This method transfers floats 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

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

If this method returns true then the FloatBuffer.array() array and FloatBuffer.arrayOffset() arrayOffset methods may safely be invoked.

The hash code of a float 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.

Writes the given float into this buffer at the current position, and then increments the position.

Writes the given float into this buffer at the given index.

This method transfers the floats remaining in the given source buffer into this buffer. If there are more floats remaining in the source buffer than in this buffer, that is, if src.remaining() > remaining(), then no floats are transferred and a BufferOverflowException is thrown.

Otherwise, this method copies n = src.remaining() floats 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

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

This method transfers floats into this buffer from the given source array. If there are more floats to be copied from the array than remain in this buffer, that is, if length > remaining(), then no floats are transferred and a BufferOverflowException is thrown.

Otherwise, this method copies length floats 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

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

This method transfers the entire content of the given source float array into this buffer. An invocation of this method of the form dst.put(a) behaves in exactly the same way as the invocation

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

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. JSR 239 does not support the mark.

The new buffer's position will be zero, its capacity and its limit will be the number of floats remaining in this buffer, and its mark will be undefined. 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. JSR 239 does not support the mark or read-only buffers.

The new buffer will be backed by the given float 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, and its mark will be undefined. Its FloatBuffer.array backing array will be the given array, and its FloatBuffer.arrayOffset array offset will be zero.

The new buffer will be backed by the given float 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, and its mark will be undefined. Its FloatBuffer.array backing array will be the given array, and its FloatBuffer.arrayOffset array offset will be zero.