org.acplt.oncrpc.server
Class OncRpcUdpServerTransport

java.lang.Object
  org.acplt.oncrpc.server.OncRpcServerTransport
      org.acplt.oncrpc.server.OncRpcUdpServerTransport

public class OncRpcUdpServerTransport
extends OncRpcServerTransport

Instances of class OncRpcUdpServerTransport encapsulate UDP/IP-based XDR streams of ONC/RPC servers. This server transport class is responsible for receiving ONC/RPC calls over UDP/IP.

See Also:

OncRpcServerTransport, OncRpcTcpServerTransport

Field Summary

private boolean	pendingDecoding Indicates that BeginDecoding has been called for the receiving XDR stream, so that it should be closed later using EndDecoding.
private XdrUdpDecodingStream	receivingXdr XDR decoding stream used when receiving requests via UDP/IP from ONC/RPC clients.
private XdrUdpEncodingStream	sendingXdr XDR encoding stream used for sending replies via UDP/IP back to an ONC/RPC client.
private java.net.DatagramSocket	socket UDP socket used for datagram-based communication with ONC/RPC clients.
private OncRpcUdpSocketHelper	socketHelper Socket helper object supplying missing methods for JDK 1.1 backwards compatibility.

Fields inherited from class org.acplt.oncrpc.server.OncRpcServerTransport

dispatcher, info, port

Constructor Summary

OncRpcUdpServerTransport(OncRpcDispatchable dispatcher, java.net.InetAddress bindAddr, int port, OncRpcServerTransportRegistrationInfo[] info, int bufferSize)
Create a new instance of a OncRpcUdpServerTransport which encapsulates UDP/IP-based XDR streams of an ONC/RPC server.

OncRpcUdpServerTransport(OncRpcDispatchable dispatcher, int port, int program, int version, int bufferSize)
Create a new instance of a OncRpcUdpServerTransport which encapsulates UDP/IP-based XDR streams of an ONC/RPC server.

OncRpcUdpServerTransport(OncRpcDispatchable dispatcher, int port, OncRpcServerTransportRegistrationInfo[] info, int bufferSize)
Create a new instance of a OncRpcUdpServerTransport which encapsulates UDP/IP-based XDR streams of an ONC/RPC server.

Method Summary

void	_listen() The real workhorse handling incoming requests, dispatching them and sending back replies.
protected void	beginEncoding(OncRpcCallInformation callInfo, OncRpcServerReplyMessage state) Begins the sending phase for ONC/RPC replies.
void	close() Close the server transport and free any resources associated with it.
protected void	endDecoding() Finishes call parameter deserialization.
protected void	endEncoding() Finishes encoding the reply to this ONC/RPC call.
java.lang.String	getCharacterEncoding() Get the character encoding for (de-)serializing strings.
protected XdrDecodingStream	getXdrDecodingStream() Returns XDR stream which can be used for deserializing the parameters of this ONC/RPC call.
protected XdrEncodingStream	getXdrEncodingStream() Returns XDR stream which can be used for eserializing the reply to this ONC/RPC call.
void	listen() Creates a new thread and uses this thread to listen to incoming ONC/RPC requests, then dispatches them and finally sends back the appropriate reply messages.
void	register() Register the UDP/IP port where this server transport waits for incoming requests with the ONC/RPC portmapper.
protected void	reply(OncRpcCallInformation callInfo, OncRpcServerReplyMessage state, XdrAble reply) Send back an ONC/RPC reply to the original caller.
protected void	retrieveCall(XdrAble call) Retrieves the parameters sent within an ONC/RPC call message.
void	setCharacterEncoding(java.lang.String characterEncoding) Set the character encoding for (de-)serializing strings.

Methods inherited from class org.acplt.oncrpc.server.OncRpcServerTransport

getPort, unregister

Methods inherited from class java.lang.Object

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

Field Detail

socket

private java.net.DatagramSocket socket

UDP socket used for datagram-based communication with ONC/RPC clients.

socketHelper

private OncRpcUdpSocketHelper socketHelper

Socket helper object supplying missing methods for JDK 1.1 backwards compatibility. So much for compile once, does not run everywhere.

sendingXdr

private XdrUdpEncodingStream sendingXdr

XDR encoding stream used for sending replies via UDP/IP back to an ONC/RPC client.

receivingXdr

private XdrUdpDecodingStream receivingXdr

XDR decoding stream used when receiving requests via UDP/IP from ONC/RPC clients.

pendingDecoding

private boolean pendingDecoding

Indicates that BeginDecoding has been called for the receiving XDR stream, so that it should be closed later using EndDecoding.

Constructor Detail

OncRpcUdpServerTransport

public OncRpcUdpServerTransport(OncRpcDispatchable dispatcher,
                                int port,
                                int program,
                                int version,
                                int bufferSize)
                         throws OncRpcException,
                                java.io.IOException

Create a new instance of a OncRpcUdpServerTransport which encapsulates UDP/IP-based XDR streams of an ONC/RPC server. Using a server transport, ONC/RPC calls are received and the corresponding replies are sent back. This constructor is a convenience constructor for those transports handling only a single ONC/RPC program and version number.

Parameters:

dispatcher - Reference to interface of an object capable of dispatching (handling) ONC/RPC calls.

port - Number of port where the server will wait for incoming calls.

program - Number of ONC/RPC program handled by this server transport.

version - Version number of ONC/RPC program handled.

bufferSize - Size of buffer for receiving and sending UDP/IP datagrams containing ONC/RPC call and reply messages.

Throws:

OncRpcException

java.io.IOException

OncRpcUdpServerTransport

public OncRpcUdpServerTransport(OncRpcDispatchable dispatcher,
                                int port,
                                OncRpcServerTransportRegistrationInfo[] info,
                                int bufferSize)
                         throws OncRpcException,
                                java.io.IOException

Create a new instance of a OncRpcUdpServerTransport which encapsulates UDP/IP-based XDR streams of an ONC/RPC server. Using a server transport, ONC/RPC calls are received and the corresponding replies are sent back. This constructor is a convenience constructor for those transports handling only a single ONC/RPC program and version number.

Parameters:

dispatcher - Reference to interface of an object capable of dispatching (handling) ONC/RPC calls.

port - Number of port where the server will wait for incoming calls.

info - Array of program and version number tuples of the ONC/RPC programs and versions handled by this transport.

bufferSize - Size of buffer for receiving and sending UDP/IP datagrams containing ONC/RPC call and reply messages.

Throws:

OncRpcException

java.io.IOException

OncRpcUdpServerTransport

public OncRpcUdpServerTransport(OncRpcDispatchable dispatcher,
                                java.net.InetAddress bindAddr,
                                int port,
                                OncRpcServerTransportRegistrationInfo[] info,
                                int bufferSize)
                         throws OncRpcException,
                                java.io.IOException

Create a new instance of a OncRpcUdpServerTransport which encapsulates UDP/IP-based XDR streams of an ONC/RPC server. Using a server transport, ONC/RPC calls are received and the corresponding replies are sent back. This constructor is a convenience constructor for those transports handling only a single ONC/RPC program and version number.

Parameters:

dispatcher - Reference to interface of an object capable of dispatching (handling) ONC/RPC calls.

bindAddr - The local Internet Address the server will bind to.

port - Number of port where the server will wait for incoming calls.

info - Array of program and version number tuples of the ONC/RPC programs and versions handled by this transport.

bufferSize - Size of buffer for receiving and sending UDP/IP datagrams containing ONC/RPC call and reply messages.

Throws:

OncRpcException

java.io.IOException

Method Detail

close

public void close()

Close the server transport and free any resources associated with it.

Note that the server transport is not deregistered. You'll have to do it manually if you need to do so. The reason for this behaviour is, that the portmapper removes all entries regardless of the protocol (TCP/IP or UDP/IP) for a given ONC/RPC program number and version.

Calling this method on a OncRpcUdpServerTransport results in the UDP network socket immediately being closed. The handler thread will therefore either terminate directly or when it tries to sent back a reply which it was about to handle at the time the close method was called.

Specified by:

close in class OncRpcServerTransport

register

public void register()
              throws OncRpcException

Register the UDP/IP port where this server transport waits for incoming requests with the ONC/RPC portmapper.

Specified by:

register in class OncRpcServerTransport

Throws:

OncRpcException - if the portmapper could not be contacted successfully.

retrieveCall

protected void retrieveCall(XdrAble call)
                     throws OncRpcException,
                            java.io.IOException

Retrieves the parameters sent within an ONC/RPC call message. It also makes sure that the deserialization process is properly finished after the call parameters have been retrieved. Under the hood this method therefore calls XdrDecodingStream.endDecoding() to free any pending resources from the decoding stage.

Specified by:

retrieveCall in class OncRpcServerTransport

Throws:

OncRpcException - if an ONC/RPC exception occurs, like the data could not be successfully deserialized.

java.io.IOException - if an I/O exception occurs, like transmission failures over the network, etc.

getXdrDecodingStream

protected XdrDecodingStream getXdrDecodingStream()

Returns XDR stream which can be used for deserializing the parameters of this ONC/RPC call. This method belongs to the lower-level access pattern when handling ONC/RPC calls.

Specified by:

getXdrDecodingStream in class OncRpcServerTransport

Returns:

Reference to decoding XDR stream.

endDecoding

protected void endDecoding()
                    throws OncRpcException,
                           java.io.IOException

Finishes call parameter deserialization. Afterwards the XDR stream returned by getXdrDecodingStream() must not be used any more. This method belongs to the lower-level access pattern when handling ONC/RPC calls.

Specified by:

endDecoding in class OncRpcServerTransport

Throws:

OncRpcException - if an ONC/RPC exception occurs, like the data could not be successfully deserialized.

java.io.IOException - if an I/O exception occurs, like transmission failures over the network, etc.

getXdrEncodingStream

protected XdrEncodingStream getXdrEncodingStream()

Returns XDR stream which can be used for eserializing the reply to this ONC/RPC call. This method belongs to the lower-level access pattern when handling ONC/RPC calls.

Specified by:

getXdrEncodingStream in class OncRpcServerTransport

Returns:

Reference to enecoding XDR stream.

beginEncoding

protected void beginEncoding(OncRpcCallInformation callInfo,
                             OncRpcServerReplyMessage state)
                      throws OncRpcException,
                             java.io.IOException

Begins the sending phase for ONC/RPC replies. This method belongs to the lower-level access pattern when handling ONC/RPC calls.

Specified by:

beginEncoding in class OncRpcServerTransport

Parameters:

callInfo - Information about ONC/RPC call for which we are about to send back the reply.

state - ONC/RPC reply header indicating success or failure.

Throws:

OncRpcException - if an ONC/RPC exception occurs, like the data could not be successfully serialized.

java.io.IOException - if an I/O exception occurs, like transmission

endEncoding

protected void endEncoding()
                    throws OncRpcException,
                           java.io.IOException

Finishes encoding the reply to this ONC/RPC call. Afterwards you must not use the XDR stream returned by getXdrEncodingStream() any longer.

Specified by:

endEncoding in class OncRpcServerTransport

Throws:

OncRpcException - if an ONC/RPC exception occurs, like the data could not be successfully serialized.

java.io.IOException - if an I/O exception occurs, like transmission failures over the network, etc.

reply

protected void reply(OncRpcCallInformation callInfo,
                     OncRpcServerReplyMessage state,
                     XdrAble reply)
              throws OncRpcException,
                     java.io.IOException

Send back an ONC/RPC reply to the original caller. This is rather a low-level method, typically not used by applications. Dispatcher handling ONC/RPC calls have to use the OncRpcCallInformation.reply(XdrAble) method instead on the call object supplied to the handler.

Specified by:

reply in class OncRpcServerTransport

Parameters:

callInfo - information about the original call, which are necessary to send back the reply to the appropriate caller.

state - ONC/RPC reply message header indicating success or failure and containing associated state information.

reply - If not null, then this parameter references the reply to be serialized after the reply message header.

Throws:

OncRpcException - if an ONC/RPC exception occurs, like the data could not be successfully serialized.

java.io.IOException - if an I/O exception occurs, like transmission failures over the network, etc.

See Also:

OncRpcCallInformation, OncRpcDispatchable

listen

public void listen()

Creates a new thread and uses this thread to listen to incoming ONC/RPC requests, then dispatches them and finally sends back the appropriate reply messages. Control in the calling thread immediately returns after the handler thread has been created.

Currently only one call after the other is dispatched, so no multithreading is done when receiving multiple calls. Instead, later calls have to wait for the current call to finish before they are handled.

Specified by:

listen in class OncRpcServerTransport

_listen

public void _listen()

The real workhorse handling incoming requests, dispatching them and sending back replies.

setCharacterEncoding

public void setCharacterEncoding(java.lang.String characterEncoding)

Set the character encoding for (de-)serializing strings.

Specified by:

setCharacterEncoding in class OncRpcServerTransport

Parameters:

characterEncoding - the encoding to use for (de-)serializing strings. If null, the system's default encoding is to be used.

getCharacterEncoding

public java.lang.String getCharacterEncoding()

Get the character encoding for (de-)serializing strings.

Specified by:

getCharacterEncoding in class OncRpcServerTransport

Returns:

the encoding currently used for (de-)serializing strings. If null, then the system's default encoding is used.