net.sf.kdgcommons.buffer

Class BufferUtil

java.lang.Object

net.sf.kdgcommons.buffer.BufferUtil

public class BufferUtil
extends Object

Contains static utility methods for working with NIO buffers.

These methods are not thread-safe unless explicityly marked as such.

Constructor Summary

Constructors

Constructor and Description
BufferUtil()

Method Summary

Modifier and Type	Method and Description
static char[]	getChars(ByteBuffer buf, int off, int count) Returns a character array from the buffer.
static String	getUTF8String(ByteBuffer buf, int off, int len) Extracts a specified sequence of bytes from a buffer and converts it to a Java String using UTF-8 encoding.
static MappedByteBuffer	map(File file, long offset, long length, FileChannel.MapMode mode) Memory maps a segment of a file.
static byte[]	toArray(ByteBuffer buf) Creates and fills a byte array that consists of all bytes from 0 to the buffer's limit.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

BufferUtil

public BufferUtil()

Method Detail

map

public static MappedByteBuffer map(File file,
                                   long offset,
                                   long length,
                                   FileChannel.MapMode mode)
                            throws IOException

Memory maps a segment of a file.

This method is thread-safe.

Parameters:

file - The file to be mapped.

offset - The starting location of the mapping within the file.

length - The number of bytes to be mapped. This is limited to Integer.MAX_VALUE, but is a long so that you can pass File.length().

mode - The mapping mode. The underlying channel will be opened using the same mode (so that you can map a read-only file).

Throws:

IOException

getUTF8String

public static String getUTF8String(ByteBuffer buf,
                                   int off,
                                   int len)

Extracts a specified sequence of bytes from a buffer and converts it to a Java String using UTF-8 encoding.

Parameters:

buf - The buffer

off - Offset within the buffer where the string starts

len - Number of bytes to be converted; caller is responsible for ensuring that the buffer has those bytes available

getChars

public static char[] getChars(ByteBuffer buf,
                              int off,
                              int count)

Returns a character array from the buffer. This method is equivalent to repeatedly calling getChar().

Parameters:

buf - The buffer

off - Offset within the buffer where conversion will start

count - The number of characters to retrieve (unlike other methods, which specify the number of bytes)

toArray

public static byte[] toArray(ByteBuffer buf)

Creates and fills a byte array that consists of all bytes from 0 to the buffer's limit. This array is independent of the buffer's backing array (if any)

Since:

1.0.15