org.apache.poi.poifs.storage
Class DataInputBlock

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

public final class DataInputBlock
extends java.lang.Object

Wraps a byte array and provides simple data input access. Internally, this class maintains a buffer read index, so that for the most part, primitive data can be read in a data-input-stream-like manner.

Note - the calling class should call the available() method to detect end-of-buffer and move to the next data block when the current is exhausted. For optimisation reasons, no error handling is performed in this class. Thus, mistakes in calling code ran may raise ugly exceptions here, like ArrayIndexOutOfBoundsException, etc .

The multi-byte primitive input methods (readUShortLE(), readIntLE() and readLongLE()) have corresponding 'spanning read' methods which (when required) perform a read across the block boundary. These spanning read methods take the previous DataInputBlock as a parameter. Reads of larger amounts of data (into byte array buffers) must be managed by the caller since these could conceivably involve more than two blocks.

Author:

Josh Micich

Method Summary

int	available()
void	readFully(byte[] buf, int off, int len) Reads len bytes from this block into the supplied buffer.
int	readIntLE() Reads an int which was encoded in little endian format.
int	readIntLE(DataInputBlock prevBlock, int prevBlockAvailable) Reads an int which spans the end of prevBlock and the start of this block.
long	readLongLE() Reads a long which was encoded in little endian format.
long	readLongLE(DataInputBlock prevBlock, int prevBlockAvailable) Reads a long which spans the end of prevBlock and the start of this block.
int	readUByte()
int	readUShortLE() Reads a short which was encoded in little endian format.
int	readUShortLE(DataInputBlock prevBlock) Reads a short which spans the end of prevBlock and the start of this block.

Methods inherited from class java.lang.Object

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

Method Detail

available

public int available()

readUByte

public int readUByte()

readUShortLE

public int readUShortLE()

Reads a short which was encoded in little endian format.

readUShortLE

public int readUShortLE(DataInputBlock prevBlock)

Reads a short which spans the end of prevBlock and the start of this block.

readIntLE

public int readIntLE()

Reads an int which was encoded in little endian format.

readIntLE

public int readIntLE(DataInputBlock prevBlock,
                     int prevBlockAvailable)

Reads an int which spans the end of prevBlock and the start of this block.

readLongLE

public long readLongLE()

Reads a long which was encoded in little endian format.

readLongLE

public long readLongLE(DataInputBlock prevBlock,
                       int prevBlockAvailable)

Reads a long which spans the end of prevBlock and the start of this block.

readFully

public void readFully(byte[] buf,
                      int off,
                      int len)

Reads len bytes from this block into the supplied buffer.