org.acplt.oncrpc
Class OncRpcUdpClient

java.lang.Object
  org.acplt.oncrpc.OncRpcClient
      org.acplt.oncrpc.OncRpcUdpClient

public class OncRpcUdpClient
extends OncRpcClient

ONC/RPC client which communicates with ONC/RPC servers over the network using the datagram-oriented protocol UDP/IP.

Field Summary

protected XdrUdpDecodingStream	receivingXdr XDR decoding stream used when receiving replies via UDP/IP from an ONC/RPC server.
protected int	retransmissionMode Retransmission mode used when resending ONC/RPC calls.
protected int	retransmissionTimeout Retransmission timeout used for resending ONC/RPC calls when an ONC/RPC server does not answer fast enough.
protected XdrUdpEncodingStream	sendingXdr XDR encoding stream used for sending requests via UDP/IP to an ONC/RPC server.
private java.net.DatagramSocket	socket UDP socket used for datagram-based communication with an ONC/RPC server.
private OncRpcUdpSocketHelper	socketHelper Socket helper object supplying missing methods for JDK 1.1 backwards compatibility.

Fields inherited from class org.acplt.oncrpc.OncRpcClient

auth, host, port, program, timeout, version, xid

Constructor Summary

OncRpcUdpClient(java.net.InetAddress host, int program, int version, int port)
Constructs a new OncRpcUdpClient object, which connects to the ONC/RPC server at host for calling remote procedures of the given { program, version }.

OncRpcUdpClient(java.net.InetAddress host, int program, int version, int port, int bufferSize)
Constructs a new OncRpcUdpClient object, which connects to the ONC/RPC server at host for calling remote procedures of the given { program, version }.

Method Summary

void	broadcastCall(int procedureNumber, XdrAble params, XdrAble result, OncRpcBroadcastListener listener) Broadcast a remote procedure call to several ONC/RPC servers.
void	call(int procedureNumber, int versionNumber, XdrAble params, XdrAble result) Calls a remote procedure on an ONC/RPC server.
void	close() Close the connection to an ONC/RPC server and free all network-related resources.
java.lang.String	getCharacterEncoding() Get the character encoding for (de-)serializing strings.
int	getRetransmissionMode() Retrieve the current retransmission mode set for retransmission of lost ONC/RPC calls.
int	getRetransmissionTimeout() Retrieve the current retransmission timeout set for remote procedure calls.
void	setCharacterEncoding(java.lang.String characterEncoding) Set the character encoding for (de-)serializing strings.
void	setRetransmissionMode(int mode) Set the retransmission mode for lost remote procedure calls.
void	setRetransmissionTimeout(int milliseconds) Set the retransmission timout for remote procedure calls to wait for an answer from the ONC/RPC server before resending the call.

Methods inherited from class org.acplt.oncrpc.OncRpcClient

call, getAuth, getHost, getPort, getProgram, getTimeout, getVersion, newOncRpcClient, newOncRpcClient, nextXid, setAuth, setTimeout

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 an ONC/RPC server.

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

protected XdrUdpEncodingStream sendingXdr

XDR encoding stream used for sending requests via UDP/IP to an ONC/RPC server.

receivingXdr

protected XdrUdpDecodingStream receivingXdr

XDR decoding stream used when receiving replies via UDP/IP from an ONC/RPC server.

retransmissionTimeout

protected int retransmissionTimeout

Retransmission timeout used for resending ONC/RPC calls when an ONC/RPC server does not answer fast enough. The default retransmission timeout is identical to the overall timeout for ONC/RPC calls (thus UDP/IP-based clients will not retransmit lost calls).

See Also:

retransmissionMode, OncRpcClient.setTimeout(int)

retransmissionMode

protected int retransmissionMode

Retransmission mode used when resending ONC/RPC calls. Default mode is fixed timeout mode.

See Also:

OncRpcUdpRetransmissionMode

Constructor Detail

OncRpcUdpClient

public OncRpcUdpClient(java.net.InetAddress host,
                       int program,
                       int version,
                       int port)
                throws OncRpcException,
                       java.io.IOException

Constructs a new OncRpcUdpClient object, which connects to the ONC/RPC server at host for calling remote procedures of the given { program, version }.

Note that the construction of an OncRpcUdpProtocolClient object will result in communication with the portmap process at host if port is 0.

Parameters:

host - The host where the ONC/RPC server resides.

program - Program number of the ONC/RPC server to call.

version - Program version number.

port - The port number where the ONC/RPC server can be contacted. If 0, then the OncRpcUdpClient object will ask the portmapper at host for the port number.

Throws:

OncRpcException - if an ONC/RPC error occurs.

java.io.IOException - if an I/O error occurs.

OncRpcUdpClient

public OncRpcUdpClient(java.net.InetAddress host,
                       int program,
                       int version,
                       int port,
                       int bufferSize)
                throws OncRpcException,
                       java.io.IOException

Constructs a new OncRpcUdpClient object, which connects to the ONC/RPC server at host for calling remote procedures of the given { program, version }.

Note that the construction of an OncRpcUdpProtocolClient object will result in communication with the portmap process at host if port is 0.

Parameters:

host - The host where the ONC/RPC server resides.

program - Program number of the ONC/RPC server to call.

version - Program version number.

port - The port number where the ONC/RPC server can be contacted. If 0, then the OncRpcUdpClient object will ask the portmapper at host for the port number.

bufferSize - The buffer size used for sending and receiving UDP datagrams.

Throws:

OncRpcException - if an ONC/RPC error occurs.

java.io.IOException - if an I/O error occurs.

Method Detail

close

public void close()
           throws OncRpcException

Close the connection to an ONC/RPC server and free all network-related resources. Well -- at least hope, that the Java VM will sometimes free some resources. Sigh.

Overrides:

close in class OncRpcClient

Throws:

OncRpcException - if an ONC/RPC error occurs.

call

public void call(int procedureNumber,
                 int versionNumber,
                 XdrAble params,
                 XdrAble result)
          throws OncRpcException

Calls a remote procedure on an ONC/RPC server.

The OncRpcUdpClient uses a similar timeout scheme as the genuine Sun C implementation of ONC/RPC: it starts with a timeout of one second when waiting for a reply. If no reply is received within this time frame, the client doubles the timeout, sends a new request and then waits again for a reply. In every case the client will wait no longer than the total timeout set through the OncRpcClient.setTimeout(int) method.

Specified by:

call in class OncRpcClient

Parameters:

procedureNumber - Procedure number of the procedure to call.

versionNumber - Protocol version number.

params - The parameters of the procedure to call, contained in an object which implements the XdrAble interface.

result - The object receiving the result of the procedure call.

Throws:

OncRpcException - if an ONC/RPC error occurs.

broadcastCall

public void broadcastCall(int procedureNumber,
                          XdrAble params,
                          XdrAble result,
                          OncRpcBroadcastListener listener)
                   throws OncRpcException

Broadcast a remote procedure call to several ONC/RPC servers. For this you'll need to specify either a multicast address or the subnet's broadcast address when creating a OncRpcUdpClient. For every reply received, an event containing the reply is sent to the OncRpcBroadcastListener listener, which is the last parameter to the this method.

In contrast to the OncRpcClient.call(int, XdrAble, XdrAble) method, broadcastCall will only send the ONC/RPC call once. It will then wait for answers until the timeout as set by OncRpcClient.setTimeout(int) expires without resending the reply.

Note that you might experience unwanted results when using authentication types other than OncRpcClientAuthNone, causing messed up authentication protocol handling objects. This depends on the type of authentication used. For AUTH_UNIX nothing bad happens as long as none of the servers replies with a shorthand verifier. If it does, then this shorthand will be used on all subsequent ONC/RPC calls, something you probably do not want at all.

Parameters:

procedureNumber - Procedure number of the procedure to call.

params - The parameters of the procedure to call, contained in an object which implements the XdrAble interface.

result - The object receiving the result of the procedure call. Note that this object is reused to deserialize all incomming replies one after another.

listener - Listener which will get an OncRpcBroadcastEvent for every reply received.

Throws:

OncRpcException - if an ONC/RPC error occurs.

setRetransmissionMode

public void setRetransmissionMode(int mode)

Set the retransmission mode for lost remote procedure calls. The default retransmission mode is OncRpcUdpRetransmissionMode.FIXED.

Parameters:

mode - Retransmission mode (either fixed or exponential).

getRetransmissionMode

public int getRetransmissionMode()

Retrieve the current retransmission mode set for retransmission of lost ONC/RPC calls.

Returns:

Current retransmission mode.

setRetransmissionTimeout

public void setRetransmissionTimeout(int milliseconds)

Set the retransmission timout for remote procedure calls to wait for an answer from the ONC/RPC server before resending the call. The default retransmission timeout is the 30 seconds. The retransmission timeout must be > 0. To disable retransmission of lost calls, set the retransmission timeout to be the same value as the timeout.

Parameters:

milliseconds - Timeout in milliseconds. A timeout of zero indicates batched calls.

getRetransmissionTimeout

public int getRetransmissionTimeout()

Retrieve the current retransmission timeout set for remote procedure calls.

Returns:

Current retransmission timeout.

setCharacterEncoding

public void setCharacterEncoding(java.lang.String characterEncoding)

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

Specified by:

setCharacterEncoding in class OncRpcClient

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 OncRpcClient

Returns:

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