eve.io.block

Class BlockInputStream

java.lang.Object

eve.io.block.BlockInputStream

All Implemented Interfaces:

IBlockInput

Direct Known Subclasses:

SecureBlockInputStream

public class BlockInputStream
extends Object
implements IBlockInput

A BlockInputStream is used to read in discrete blocks of data as sent by BlockOutputStream. The data sent by the BlockOutputStream may be Secure Documents as represented by eve.security.SecureDocument and this BlockInputStream will then attempt to decode and validate them using the encryption parameters as provided by setPassword() and setKeys().

Field Summary

Fields

Modifier and Type	Field and Description
protected InputStream	in
protected byte[]	intBuff
static int	maximumInputBlockSize By default this is 5 MB.

Constructor Summary

Constructors

Constructor and Description
BlockInputStream(InputStream in) Create a BlockInputStream using the provided InputStream for reading in data.

Method Summary

Modifier and Type	Method and Description
int	blockRead(ByteArray dest) Read and append a block to the destination ByteArray.
void	close() close this BlockInputStream and the underlying input stream.
protected void	decrypt(byte[] data, int offset, int length, ByteArray dest) If the incoming data block is encoded/encrypted then after it is read in the raw bytes are passed to this method before being returned.
ByteArray	readBlock() This is used to read the next block of incoming data.
ByteArray	readBlock(ByteArray dest) This is used to read the next block of incoming data.

Methods inherited from class java.lang.Object

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

Field Detail

in

protected InputStream in

intBuff

protected byte[] intBuff

maximumInputBlockSize

public static int maximumInputBlockSize

By default this is 5 MB. If any incoming block is bigger than this an IOException is thrown.

Constructor Detail

BlockInputStream

public BlockInputStream(InputStream in)

Create a BlockInputStream using the provided InputStream for reading in data.

Method Detail

readBlock

public ByteArray readBlock(ByteArray dest)
                    throws IOException,
                           UnknownEncodingException

This is used to read the next block of incoming data.

Parameters:

dest - an optional destination ByteArray. If this is null a new one is created. The destination ByteArray is always cleared before the new data is added.

Returns:

the destination ByteArray or a new ByteArray. On a clean end-of-stream this will return null.

Throws:

IOException - if an error occured reading or decoding or decrypting the data.

UnknownEncodingException - if the data could not be decoded/decrypted.

decrypt

protected void decrypt(byte[] data,
                       int offset,
                       int length,
                       ByteArray dest)
                throws UnknownEncodingException,
                       IOException

If the incoming data block is encoded/encrypted then after it is read in the raw bytes are passed to this method before being returned. By default this method will throw an UnknownEncodingException.

Parameters:

data - the data bytes read in.

offset - the offset of the data.

length - the number of bytes of data.

dest - a destination ByteArray that will not be null and would have been cleared before being passed here.

Throws:

UnknownEncodingException - if the data could not be decoded/decrypted.

IOException - if there was a problem decrypting the data.

readBlock

public final ByteArray readBlock()
                          throws IOException

This is used to read the next block of incoming data.

Returns:

A new ByteArray containing the data or null if the stream has closed cleanly.

Throws:

IOException - if an error occured reading or decoding or decrypting the data.

close

public void close()
           throws IOException

close this BlockInputStream and the underlying input stream.

Specified by:

close in interface IBlockInput

Throws:

IOException - if an error occured closing the underlying stream.

blockRead

public int blockRead(ByteArray dest)
              throws IOException

Description copied from interface: IBlockInput

Read and append a block to the destination ByteArray.

Specified by:

blockRead in interface IBlockInput

Parameters:

dest - the destination ByteArray, which must not be null.

Returns:

the number of bytes read or -1 if the stream has been closed.

Throws:

IOException