Package org.acplt.oncrpc

Class XdrUdpDecodingStream

java.lang.Object
org.acplt.oncrpc.XdrDecodingStream
org.acplt.oncrpc.XdrUdpDecodingStream
public class XdrUdpDecodingStream extends XdrDecodingStream
The XdrUdpDecodingStream class provides the necessary functionality to XdrDecodingStream to receive XDR packets from the network using the datagram-oriented UDP/IP.
Version:
$Revision: 1.2 $ $Date: 2005/11/11 21:07:40 $ $State: Exp $ $Locker: $
Author:
Harald Albrecht

  • Constructor Details

    • XdrUdpDecodingStream

      public XdrUdpDecodingStream(DatagramSocket datagramSocket, int bufferSize)
      Construct a new XdrUdpDecodingStream object and associate it with the given datagramSocket for UDP/IP-based communication. This constructor is typically used when communicating with servers over UDP/IP using a "connected" datagram socket.
      Parameters:
      datagramSocket - Datagram socket from which XDR data is received.
      bufferSize - Size of packet buffer for storing received XDR datagrams.

  • Method Details

    • getSenderAddress

      public InetAddress getSenderAddress()
      Returns the Internet address of the sender of the current XDR data. This method should only be called after beginDecoding(), otherwise it might return stale information.
      Specified by:
      getSenderAddress in class XdrDecodingStream
      Returns:
      InetAddress of the sender of the current XDR data.

    • getSenderPort

      public int getSenderPort()
      Returns the port number of the sender of the current XDR data. This method should only be called after beginDecoding(), otherwise it might return stale information.
      Specified by:
      getSenderPort in class XdrDecodingStream
      Returns:
      Port number of the sender of the current XDR data.

    • beginDecoding

      public void beginDecoding() throws OncRpcException, IOException
      Initiates decoding of the next XDR record. For UDP-based XDR decoding streams this reads in the next datagram from the network socket.
      Specified by:
      beginDecoding in class XdrDecodingStream
      Throws:
      OncRpcException - if an ONC/RPC error occurs.
      IOException - if an I/O error occurs.

    • endDecoding

      public void endDecoding() throws OncRpcException, IOException
      End decoding of the current XDR record. The general contract of endDecoding is that calling it is an indication that the current record is no more interesting to the caller and any allocated data for this record can be freed.

      This method overrides XdrDecodingStream.endDecoding(). It does nothing more than resetting the buffer pointer (eeek! a pointer in Java!!!) back to the begin of an empty buffer, so attempts to decode data will fail until the buffer is filled again.

      Overrides:
      endDecoding in class XdrDecodingStream
      Throws:
      OncRpcException - if an ONC/RPC error occurs.
      IOException - if an I/O error occurs.

    • close

      public void close() throws OncRpcException, IOException
      Closes this decoding XDR stream and releases any system resources associated with this stream. A closed XDR stream cannot perform decoding operations and cannot be reopened.

      This implementation frees the allocated buffer but does not close the associated datagram socket. It only throws away the reference to this socket.

      Overrides:
      close in class XdrDecodingStream
      Throws:
      OncRpcException - if an ONC/RPC error occurs.
      IOException - if an I/O error occurs.

    • xdrDecodeInt

      public int xdrDecodeInt() throws OncRpcException, IOException
      Decodes (aka "deserializes") a "XDR int" value received from a XDR stream. A XDR int is 32 bits wide -- the same width Java's "int" data type has.
      Specified by:
      xdrDecodeInt in class XdrDecodingStream
      Returns:
      The decoded int value.
      Throws:
      OncRpcException - if an ONC/RPC error occurs.
      IOException - if an I/O error occurs.

    • xdrDecodeOpaque

      public byte[] xdrDecodeOpaque(int length) throws OncRpcException, IOException
      Decodes (aka "deserializes") an opaque value, which is nothing more than a series of octets (or 8 bits wide bytes). Because the length of the opaque value is given, we don't need to retrieve it from the XDR stream. This is different from xdrDecodeOpaque(byte[], int, int) where first the length of the opaque value is retrieved from the XDR stream.
      Specified by:
      xdrDecodeOpaque in class XdrDecodingStream
      Parameters:
      length - Length of opaque data to decode.
      Returns:
      Opaque data as a byte vector.
      Throws:
      OncRpcException - if an ONC/RPC error occurs.
      IOException - if an I/O error occurs.

    • xdrDecodeOpaque

      public void xdrDecodeOpaque(byte[] opaque, int offset, int length) throws OncRpcException, IOException
      Decodes (aka "deserializes") a XDR opaque value, which is represented by a vector of byte values, and starts at offset with a length of length. Only the opaque value is decoded, so the caller has to know how long the opaque value will be. The decoded data is always padded to be a multiple of four (because that's what the sender does).
      Specified by:
      xdrDecodeOpaque in class XdrDecodingStream
      Parameters:
      opaque - Byte vector which will receive the decoded opaque value.
      offset - Start offset in the byte vector.
      length - the number of bytes to decode.
      Throws:
      OncRpcException - if an ONC/RPC error occurs.
      IOException - if an I/O error occurs.