Class 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 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)
    • 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.