org.acplt.oncrpc
Class XdrUdpEncodingStream

java.lang.Object
  org.acplt.oncrpc.XdrEncodingStream
      org.acplt.oncrpc.XdrUdpEncodingStream

public class XdrUdpEncodingStream
extends XdrEncodingStream

The XdrUdpDecodingStream class provides the necessary functionality to XdrDecodingStream to send XDR packets over the network using the datagram-oriented UDP/IP.

Field Summary

private byte[]	buffer The buffer which will receive the encoded information, before it is sent via a datagram socket.
private int	bufferHighmark Index of the last four byte word in the buffer.
private int	bufferIndex The write pointer is an index into the buffer.
private static byte[]	paddingZeros Some zeros, only needed for padding -- like in real life.
private java.net.InetAddress	receiverAddress Receiver address of current buffer contents when flushed.
private int	receiverPort The receiver's port.
private java.net.DatagramSocket	socket The datagram socket to be used when sending this XDR stream's buffer contents.

Constructor Summary

XdrUdpEncodingStream(java.net.DatagramSocket datagramSocket, int bufferSize)
Creates a new UDP-based encoding XDR stream, associated with the given datagram socket.

Method Summary

void	beginEncoding(java.net.InetAddress receiverAddress, int receiverPort) Begins encoding a new XDR record.
void	close() Closes this encoding XDR stream and releases any system resources associated with this stream.
void	endEncoding() Flushes this encoding XDR stream and forces any buffered output bytes to be written out.
void	xdrEncodeInt(int value) Encodes (aka "serializes") a "XDR int" value and writes it down a XDR stream.
void	xdrEncodeOpaque(byte[] value, int offset, int length) Encodes (aka "serializes") a XDR opaque value, which is represented by a vector of byte values, and starts at offset with a length of length.

Methods inherited from class org.acplt.oncrpc.XdrEncodingStream

getCharacterEncoding, setCharacterEncoding, xdrEncodeBoolean, xdrEncodeBooleanFixedVector, xdrEncodeBooleanVector, xdrEncodeByte, xdrEncodeByteFixedVector, xdrEncodeByteVector, xdrEncodeDouble, xdrEncodeDoubleFixedVector, xdrEncodeDoubleVector, xdrEncodeDynamicOpaque, xdrEncodeFloat, xdrEncodeFloatFixedVector, xdrEncodeFloatVector, xdrEncodeIntFixedVector, xdrEncodeIntVector, xdrEncodeLong, xdrEncodeLongFixedVector, xdrEncodeLongVector, xdrEncodeOpaque, xdrEncodeOpaque, xdrEncodeShort, xdrEncodeShortFixedVector, xdrEncodeShortVector, xdrEncodeString, xdrEncodeStringFixedVector, xdrEncodeStringVector

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

The datagram socket to be used when sending this XDR stream's buffer contents.

receiverAddress

private java.net.InetAddress receiverAddress

Receiver address of current buffer contents when flushed.

receiverPort

private int receiverPort

The receiver's port.

buffer

private byte[] buffer

The buffer which will receive the encoded information, before it is sent via a datagram socket.

bufferIndex

private int bufferIndex

The write pointer is an index into the buffer.

bufferHighmark

private int bufferHighmark

Index of the last four byte word in the buffer.

paddingZeros

private static final byte[] paddingZeros

Some zeros, only needed for padding -- like in real life.

Constructor Detail

XdrUdpEncodingStream

public XdrUdpEncodingStream(java.net.DatagramSocket datagramSocket,
                            int bufferSize)

Creates a new UDP-based encoding XDR stream, associated with the given datagram socket.

Parameters:

datagramSocket - Datagram-based socket to use to get rid of encoded data.

bufferSize - Size of buffer to store encoded data before it is sent as one datagram.

Method Detail

beginEncoding

public void beginEncoding(java.net.InetAddress receiverAddress,
                          int receiverPort)
                   throws OncRpcException,
                          java.io.IOException

Begins encoding a new XDR record. This involves resetting this encoding XDR stream back into a known state.

Overrides:

beginEncoding in class XdrEncodingStream

Parameters:

receiverAddress - Indicates the receiver of the XDR data. This can be null for XDR streams connected permanently to a receiver (like in case of TCP/IP based XDR streams).

receiverPort - Port number of the receiver.

Throws:

OncRpcException - if an ONC/RPC error occurs.

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

endEncoding

public void endEncoding()
                 throws OncRpcException,
                        java.io.IOException

Flushes this encoding XDR stream and forces any buffered output bytes to be written out. The general contract of endEncoding is that calling it is an indication that the current record is finished and any bytes previously encoded should immediately be written to their intended destination.

Overrides:

endEncoding in class XdrEncodingStream

Throws:

OncRpcException - if an ONC/RPC error occurs.

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

close

public void close()
           throws OncRpcException,
                  java.io.IOException

Closes this encoding XDR stream and releases any system resources associated with this stream. The general contract of close is that it closes the encoding XDR stream. A closed XDR stream cannot perform encoding operations and cannot be reopened.

Overrides:

close in class XdrEncodingStream

Throws:

OncRpcException - if an ONC/RPC error occurs.

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

xdrEncodeInt

public void xdrEncodeInt(int value)
                  throws OncRpcException,
                         java.io.IOException

Encodes (aka "serializes") a "XDR int" value and writes it down a XDR stream. A XDR int is 32 bits wide -- the same width Java's "int" data type has. This method is one of the basic methods all other methods can rely on.

Specified by:

xdrEncodeInt in class XdrEncodingStream

Parameters:

value - The int value to be encoded.

Throws:

OncRpcException - if an ONC/RPC error occurs.

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

xdrEncodeOpaque

public void xdrEncodeOpaque(byte[] value,
                            int offset,
                            int length)
                     throws OncRpcException,
                            java.io.IOException

Encodes (aka "serializes") 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 encoded, but no length indication is preceeding the opaque value, so the receiver has to know how long the opaque value will be. The encoded data is always padded to be a multiple of four. If the given length is not a multiple of four, zero bytes will be used for padding.

Specified by:

xdrEncodeOpaque in class XdrEncodingStream

Parameters:

value - The opaque value to be encoded in the form of a series of bytes.

offset - Start offset in the data.

length - the number of bytes to encode.

Throws:

OncRpcException - if an ONC/RPC error occurs.

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