com.hp.util.net

Class ByteMessageTransfer

java.lang.Object

com.hp.util.net.ByteMessageTransfer

public class ByteMessageTransfer
extends Object

Utility for writing and consuming length-prefixed messages from the specified output or input stream. The length is specified as the leading two bytes immediately after the two start-of-frame bytes.

Author:

Thomas Vachuska

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_MAX_BUFFER_SIZE

Constructor Summary

Constructors

Constructor and Description
ByteMessageTransfer() Create a new transfer setup to deal with messages of default maximum size, which is 1024 bytes.
ByteMessageTransfer(int maxBufferSize) Create a new transfer setup to deal with messages of specified maximum size.

Method Summary

Modifier and Type	Method and Description
int	getMaxBufferSize() Get the current maximum buffer size supported by this byte transfer.
byte[]	read(InputStream input) Read length-prefixed data from the specified input stream and return a newly allocated byte buffer that holds the data.
int	readSOF(InputStream input) Read and validate the length-prefixed start of frame from the specified input stream and return the decoded length of the expected message.
void	setMaxBufferSize(int maxBufferSize) Set the current maximum buffer size supported by this byte transfer.
void	write(OutputStream output, byte[] data) Write the given byte buffer to the specified output stream using the length-prefixed transfer.
void	write(OutputStream output, byte[] data, int offset, int length) Write the given section of a byte buffer to the specified output stream using the length-prefixed transfer.
void	write(OutputStream output, Writable w) Write the given writable to the specified output stream using the length-prefixed transfer.
int	writeSOF(OutputStream output, int length) Write a start of frame of the length-prefixed message.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_MAX_BUFFER_SIZE

public static final int DEFAULT_MAX_BUFFER_SIZE

See Also:

Constant Field Values

Constructor Detail

ByteMessageTransfer

public ByteMessageTransfer()

Create a new transfer setup to deal with messages of default maximum size, which is 1024 bytes.

ByteMessageTransfer

public ByteMessageTransfer(int maxBufferSize)

Create a new transfer setup to deal with messages of specified maximum size.

Parameters:

maxBufferSize - maximum size of messages processed by this transfer

Method Detail

getMaxBufferSize

public int getMaxBufferSize()

Get the current maximum buffer size supported by this byte transfer.

Returns:

maximum number of bytes allowed in a single transfer

setMaxBufferSize

public void setMaxBufferSize(int maxBufferSize)

Set the current maximum buffer size supported by this byte transfer.

Parameters:

maxBufferSize - maximum number of bytes allowed in a single transfer

write

public void write(OutputStream output,
                  byte[] data)
           throws IOException

Write the given byte buffer to the specified output stream using the length-prefixed transfer.

Parameters:

output - output stream to write to

data - byte buffer to write

Throws:

IOException - if issues encountered writing the message

writeSOF

public int writeSOF(OutputStream output,
                    int length)
             throws IOException

Write a start of frame of the length-prefixed message.

Parameters:

output - output stream to write to

length - size of the message being written

Returns:

number of bytes to be written after the header

Throws:

IOException - if issues encountered writing the header

write

public void write(OutputStream output,
                  byte[] data,
                  int offset,
                  int length)
           throws IOException

Write the given section of a byte buffer to the specified output stream using the length-prefixed transfer.

Parameters:

output - output stream to write to

data - byte buffer to write

offset - offset at which to start the transfer

length - number of bytes to transfer

Throws:

IOException - if issues encountered writing the data

write

public void write(OutputStream output,
                  Writable w)
           throws IOException

Write the given writable to the specified output stream using the length-prefixed transfer.

Parameters:

output - output stream to write to

w - writable object to write

Throws:

IOException - if issues encountered writing the message

readSOF

public int readSOF(InputStream input)
            throws IOException

Read and validate the length-prefixed start of frame from the specified input stream and return the decoded length of the expected message.

Parameters:

input - input stream from which to read

Returns:

length of the expected message

Throws:

IOException - if issues encountered reading the header

read

public byte[] read(InputStream input)
            throws IOException

Read length-prefixed data from the specified input stream and return a newly allocated byte buffer that holds the data.

Parameters:

input - input stream from which to read

Returns:

byte buffer with read data

Throws:

IOException - if issues encountered reading the message