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.
Version:
$Revision: 1.6 $ $Date: 2007/05/29 18:48:27 $ $State: Exp $ $Locker: $
Author:
Harald Albrecht
  • Field Details

    • socket

      private 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

      protected int retransmissionMode
      Retransmission mode used when resending ONC/RPC calls. Default mode is fixed timeout mode.
      See Also:
  • Constructor Details

    • OncRpcUdpClient

      public OncRpcUdpClient(InetAddress host, int program, int version, int port) throws OncRpcException, 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.
      IOException - if an I/O error occurs.
    • OncRpcUdpClient

      public OncRpcUdpClient(InetAddress host, int program, int version, int port, int bufferSize) throws OncRpcException, 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.
      IOException - if an I/O error occurs.
  • Method Details

    • 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(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 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.