de.bb.bejy
Class Protocol

java.lang.Object
  |
  +--de.bb.bejy.Protocol

public abstract class Protocol

extends java.lang.Object

base class for all protocols used in BEJY.

provides some usefull functions to handle incoming data

Field Summary

protected Factory	factory reference to this protocol's factory
protected java.io.InputStream	is the input stream to read from
protected java.io.OutputStream	os the output stream to write to
protected java.lang.String	remoteAddress address ot the other side
protected de.bb.bejy.Server	server reference to this protocol's server (thread)

Constructor Summary

protected

Protocol(Factory f) the only constructor

Method Summary

protected abstract boolean	doit() contains the protocol main loop.
protected boolean	goodStream() checks whether current streams are still usable
protected ByteRef	readFirst() read the first available bytes into a ByteArray object
protected ByteRef	readLine(ByteRef br) read the next line into a ByteArray using a 2nd ByteArray as buffer. If there is no complete line in the provided buffer, the next chunk of data is read from the input stream.
protected void	trigger() a callback function which is called before the server starts to listen for incoming data. Necessary when the server must send data before the clients starts sending.

Methods inherited from class java.lang.Object

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

Field Detail

os

protected java.io.OutputStream os

the output stream to write to

is

protected java.io.InputStream is

the input stream to read from

factory

protected Factory factory

reference to this protocol's factory

server

protected de.bb.bejy.Server server

reference to this protocol's server (thread)

remoteAddress

protected java.lang.String remoteAddress

address ot the other side

Constructor Detail

Protocol

protected Protocol(Factory f)

the only constructor

Parameters:

f - the Factory object which creates this object

Method Detail

doit

protected abstract boolean doit()
                         throws java.lang.Exception

contains the protocol main loop.

Returns:

true when the established connection is reused

false when a new connection must be established

in both cases the server object and the protocol object is reused

Throws:

java.lang.Exception - indicates that even the server object must be discarded

java.lang.Exception -

goodStream

protected boolean goodStream()

checks whether current streams are still usable

Returns:

true if streams are usable

trigger

protected void trigger()
                throws java.lang.Exception

a callback function which is called before the server starts to listen for incoming data.
Necessary when the server must send data before the clients starts sending. E.g. SMTP or POP3 protocols send first data to the client, before they start to read data.

Throws:

java.lang.Exception -

readFirst

protected ByteRef readFirst()

read the first available bytes into a ByteArray object

Returns:

returns a ByteArray containing the first chunk of read data or null at EOS

readLine

protected ByteRef readLine(ByteRef br)

read the next line into a ByteArray using a 2nd ByteArray as buffer.
If there is no complete line in the provided buffer, the next chunk of data is read from the input stream.

Parameters:

br - the read buffer which contains already read data

Returns:

returns a ByteArray referring to the next line of data or null at EOS