org.apache.poi.poifs.storage
Class SmallDocumentBlock

java.lang.Object
  org.apache.poi.poifs.storage.SmallDocumentBlock

All Implemented Interfaces:

BlockWritable, ListManagedBlock

public class SmallDocumentBlock
extends java.lang.Object
implements BlockWritable, ListManagedBlock

Storage for documents that are too small to use regular DocumentBlocks for their data

Author:

Marc Johnson (mjohnson at apache dot org)

Method Summary

static int	calcSize(int size) Calculate the storage size of a set of SmallDocumentBlocks
static SmallDocumentBlock[]	convert(BlockWritable[] store, int size) Factory for creating SmallDocumentBlocks from DocumentBlocks
static SmallDocumentBlock[]	convert(byte[] array, int size) convert a single long array into an array of SmallDocumentBlock instances
static java.util.List	extract(ListManagedBlock[] blocks) create a list of SmallDocumentBlock's from raw data
static int	fill(java.util.List blocks) fill out a List of SmallDocumentBlocks so that it fully occupies a set of big blocks
byte[]	getData() Get the data from the block
static void	read(BlockWritable[] blocks, byte[] buffer, int offset) read data from an array of SmallDocumentBlocks
void	writeBlocks(java.io.OutputStream stream) Write the storage to an OutputStream

Methods inherited from class java.lang.Object

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

Method Detail

convert

public static SmallDocumentBlock[] convert(byte[] array,
                                           int size)

convert a single long array into an array of SmallDocumentBlock instances

Parameters:

array - the byte array to be converted

size - the intended size of the array (which may be smaller)

Returns:

an array of SmallDocumentBlock instances, filled from the array

fill

public static int fill(java.util.List blocks)

fill out a List of SmallDocumentBlocks so that it fully occupies a set of big blocks

Parameters:

blocks - the List to be filled out

Returns:

number of big blocks the list encompasses

convert

public static SmallDocumentBlock[] convert(BlockWritable[] store,
                                           int size)
                                    throws java.io.IOException,
                                           java.lang.ArrayIndexOutOfBoundsException

Factory for creating SmallDocumentBlocks from DocumentBlocks

Parameters:

store - the original DocumentBlocks

size - the total document size

Returns:

an array of new SmallDocumentBlocks instances

Throws:

java.io.IOException - on errors reading from the DocumentBlocks

java.lang.ArrayIndexOutOfBoundsException - if, somehow, the store contains less data than size indicates

extract

public static java.util.List extract(ListManagedBlock[] blocks)
                              throws java.io.IOException

create a list of SmallDocumentBlock's from raw data

Parameters:

blocks - the raw data containing the SmallDocumentBlock data

Returns:

a List of SmallDocumentBlock's extracted from the input

Throws:

java.io.IOException

read

public static void read(BlockWritable[] blocks,
                        byte[] buffer,
                        int offset)

read data from an array of SmallDocumentBlocks

Parameters:

blocks - the blocks to read from

buffer - the buffer to write the data into

offset - the offset into the array of blocks to read from

calcSize

public static int calcSize(int size)

Calculate the storage size of a set of SmallDocumentBlocks

Parameters:

size - number of SmallDocumentBlocks

Returns:

total size

writeBlocks

public void writeBlocks(java.io.OutputStream stream)
                 throws java.io.IOException

Write the storage to an OutputStream

Specified by:

writeBlocks in interface BlockWritable

Parameters:

stream - the OutputStream to which the stored data should be written

Throws:

java.io.IOException - on problems writing to the specified stream

getData

public byte[] getData()
               throws java.io.IOException

Get the data from the block

Specified by:

getData in interface ListManagedBlock

Returns:

the block's data as a byte array

Throws:

java.io.IOException - if there is no data