Class 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.
    Version:
    $Revision: 1.4 $ $Date: 2008/01/02 15:13:35 $ $State: Exp $ $Locker: $
    Author:
    Harald Albrecht
    See Also:
    OncRpcServerTransport, OncRpcTcpServerTransport
    • 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.