Package fr.dyade.aaa.agent

Class MessageInputStream

java.lang.Object

java.io.InputStream

fr.dyade.aaa.agent.MessageInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

Direct Known Subclasses:

BufferedMessageInputStream, ByteArrayMessageInputStream

public abstract class MessageInputStream
extends InputStream

Class used to receive messages through a stream.

Be careful this InputStream is not synchronized.

Field Summary

Fields

Modifier and Type	Field	Description
protected byte[]	buf	The internal buffer where data is stored.
protected boolean	compressedFlows
protected int	count	The number of valid bytes in the buffer.
protected int	pos	The current position in the buffer.

Constructor Summary

Constructors

Constructor	Description
MessageInputStream()	Creates a MessageInputStream.

Method Summary

Modifier and Type	Method	Description
abstract int	read()	Reads the next byte of data from the input stream.
int	read(byte[] b)	Reads some number of bytes from the input stream and stores them into the buffer array b.
abstract int	read(byte[] b, int off, int len)	Reads up to len bytes of data from the input stream into an array of bytes.
protected abstract void	readFully(int length)	Reads length bytes of data from the input stream.
protected abstract void	readHeader()	Reads the protocol header from this output stream.
protected int	readInt()	Reads an int directly from the buffer.
protected Message	readMessage()	Reads the message from this input stream.
protected void	readMessageHeader(Message msg)	Reads the message header data from the buffer.
protected short	readShort()	Reads a short directly from the buffer.

Methods inherited from class java.io.InputStream

available, close, mark, markSupported, nullInputStream, readAllBytes, readNBytes, readNBytes, reset, skip, transferTo

Methods inherited from class java.lang.Object

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

Field Detail

buf

protected byte[] buf

The internal buffer where data is stored.

count

protected int count

The number of valid bytes in the buffer.

The index one greater than the index of the last valid byte in the buffer.

This value is always in the range 0 through buf.length; elements buf[0] through buf[count-1] contain valid byte data.

pos

protected int pos

The current position in the buffer. This is the index of the next character to be read from the buf array.

This value is always in the range 0 through count. If it is less than count, then buf[pos] is the next byte to be supplied as input; if it is equal to count, then the next read or skip operation will require more bytes to be read from the contained input stream.

compressedFlows

protected boolean compressedFlows

Constructor Detail

MessageInputStream

MessageInputStream()

Creates a MessageInputStream.

Method Detail

read

public abstract int read()
                  throws IOException

Reads the next byte of data from the input stream. The value byte is returned as an int in the range 0 to 255. If no byte is available because the end of the stream has been reached, the value -1 is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.

Subclass must provide an implementation of this method.

Specified by:

read in class InputStream

Returns:

the next byte of data, or -1 if the end of the stream is reached.

Throws:

IOException - if an I/O error occurs.

read

public final int read(byte[] b)
               throws IOException

Reads some number of bytes from the input stream and stores them into the buffer array b. The number of bytes actually read is returned as an integer. This method blocks until input data is available, end of file is detected, or an exception is thrown.

The read(b) method for class InputStream has the same effect as: read(b, 0, b.length)

Overrides:

read in class InputStream

Parameters:

b - the buffer into which the data is read.

Returns:

the total number of bytes read into the buffer, or -1 is there is no more data because the end of the stream has been reached.

Throws:

IOException - If the first byte cannot be read for any reason other than the end of the file, if the input stream has been closed, or if some other I/O error occurs.

NullPointerException - if b is null.

read

public abstract int read(byte[] b,
                         int off,
                         int len)
                  throws IOException

Reads up to len bytes of data from the input stream into an array of bytes. An attempt is made to read as many as len bytes, but a smaller number may be read. The number of bytes actually read is returned as an integer.

This method blocks until input data is available, end of file is detected, or an exception is thrown.

Overrides:

read in class InputStream

Parameters:

b - the buffer into which the data is read.

off - the start offset in array b at which the data is written.

len - the maximum number of bytes to read.

Returns:

the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached.

Throws:

IOException - If the first byte cannot be read for any reason other than end of file, or if the input stream has been closed, or if some other I/O error occurs.

NullPointerException - If b is null.

IndexOutOfBoundsException - If off is negative, len is negative, or len is greater than b.length - off

readShort

protected final short readShort()

Reads a short directly from the buffer. Be careful, the buffer must contain enough data to read the short.

Returns:

the short.

readInt

protected final int readInt()

Reads an int directly from the buffer. Be careful, the buffer must contain enough data to read the int.

Returns:

the int.

readHeader

protected abstract void readHeader()
                            throws IOException

Reads the protocol header from this output stream. Be careful, the buffer must contain enough data to read the short. This method must be overloaded in subclass.

Throws:

IOException - an error occurs.

readMessageHeader

protected final void readMessageHeader(Message msg)
                                throws IOException

Reads the message header data from the buffer.

Parameters:

msg - The message to complete.

Throws:

IOException - an error occurs.

readMessage

protected final Message readMessage()
                             throws Exception

Reads the message from this input stream.

Returns:

the incoming message.

Throws:

Exception - an error occurs.

readFully

protected abstract void readFully(int length)
                           throws IOException

Reads length bytes of data from the input stream. This method returns when length bytes are available or if end of stream is reached.

Parameters:

length - number of byte to read.

Throws:

IOException - an error occurs.