com.voytechs.jnetstream.io
Class CaptureOutputStream

java.lang.Object
  java.io.OutputStream
      com.voytechs.jnetstream.io.ProtocolDataOutputStream
          com.voytechs.jnetstream.io.PacketOutputStream
              com.voytechs.jnetstream.io.CaptureOutputStream

All Implemented Interfaces:

java.io.Closeable, java.io.Flushable

Direct Known Subclasses:

PcapOutputStream, SnoopOutputStream

public abstract class CaptureOutputStream
extends PacketOutputStream

Base abstract class for all Capture file specific *OutputStream objects. This method is provides generic interfaces and algorithms to help support writting of new capture file.

Main methods are write(), any of the write methods defined in ProtocolDataOutputStream to write native java types or the copy method which is used to copy contents from one capture file to another, possibly in a nother capture format completely.

Important note: Its is very important to call close() when done writting data out to the stream. This finalizes the stream and writes out any remaining padding and headers to the stream before closing it. Without an explicit call to close() last record written may be incomplete.

Field Summary

Fields inherited from class com.voytechs.jnetstream.io.ProtocolDataOutputStream

bitsLeft, cachedByte, out

Constructor Summary

CaptureOutputStream(java.io.OutputStream out)
Uses the given output stream to write new capture file.

CaptureOutputStream(java.lang.String file)
Uses the given file to write new capture file.

Method Summary

void	close() Finish writting data to the output stream.
void	copy(PacketInputStream in) Copy from PacketInputStream to another.
protected abstract void	initPacketStream() Write out the main capture file header into the capture stream.
static void	main(java.lang.String[] args) Test function for CaptureOutputStream
void	nextPacket(long captureMillis, int captureNanos, long snaplen, long length) Initiializes the capture file header.
void	nextPacket(PacketInputStream in) Initiializes the capture file header.
protected abstract void	writeRecordHeader(long captureMillis, int captureNanos, long snaplen, long length) Writes the capture file record header.

Methods inherited from class com.voytechs.jnetstream.io.PacketOutputStream

write

Methods inherited from class com.voytechs.jnetstream.io.ProtocolDataOutputStream

flush, unloadCachedByte, write, write, write, writeByte, writeInt, writeL, writeLByte, writeLInt, writeLLong, writeLong, writeLShort, writeShort, writeUByte, writeUInt, writeULByte, writeULInt, writeULLong, writeULong, writeULShort, writeUShort

Methods inherited from class java.io.OutputStream

write

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CaptureOutputStream

public CaptureOutputStream(java.io.OutputStream out)
                    throws java.io.IOException,
                           StreamFormatException

Uses the given output stream to write new capture file. No META data is extracted.

Parameters:

out - Output stream to new capture file.

Throws:

java.io.IOException

StreamFormatException

CaptureOutputStream

public CaptureOutputStream(java.lang.String file)
                    throws java.io.FileNotFoundException,
                           java.io.IOException,
                           StreamFormatException

Uses the given file to write new capture file. No META data is extracted.

Parameters:

file -

Throws:

java.io.FileNotFoundException

java.io.IOException

StreamFormatException

Method Detail

initPacketStream

protected abstract void initPacketStream()
                                  throws java.io.IOException,
                                         StreamFormatException

Write out the main capture file header into the capture stream.

Specified by:

initPacketStream in class PacketOutputStream

Throws:

java.io.IOException - Any I/O errors while writting the header.

StreamFormatException

writeRecordHeader

protected abstract void writeRecordHeader(long captureMillis,
                                          int captureNanos,
                                          long snaplen,
                                          long length)
                                   throws java.io.IOException

Writes the capture file record header. This is very format specific write.

Parameters:

captureMillis -

captureNanos -

snaplen -

length -

Throws:

java.io.IOException

nextPacket

public void nextPacket(PacketInputStream in)
                throws java.io.IOException

Initiializes the capture file header. Extracts the required attributes from he InputStream. If the next packet will not be based on the exact contents of the input stream, such that snpalen and packet length attributes are incorrect, do not use this method, but set the expected packet attributes explicitely with the other variation of nextPacket() method.

Parameters:

in - InputStream to extract certain information from about then next packet.

Throws:

java.io.IOException - Any I/O errors.

See Also:

nextPacket(long captureMillis, int captureNanos, long snaplen, long length)

nextPacket

public void nextPacket(long captureMillis,
                       int captureNanos,
                       long snaplen,
                       long length)
                throws java.io.IOException

Initiializes the capture file header. Extracts the required attributes from he InputStream.

Parameters:

captureMillis - Number of milli seconds from 1970 when packet was captured.

captureNanos - Number nano seconds as additional time fragment in the capture timestamp.

snaplen - Number of bytes captured in the packet.

length - Number of bytes in the original packet, may differ from snaplen.

Throws:

java.io.IOException - Any I/O errors.

close

public void close()
           throws java.io.IOException

Finish writting data to the output stream. This allows the stream to finalize, write out any last padding or closing headers.

Specified by:

close in interface java.io.Closeable

Overrides:

close in class java.io.OutputStream

Throws:

java.io.IOException - Any I/O errors.

copy

public void copy(PacketInputStream in)
          throws java.io.IOException,
                 StreamFormatException

Copy from PacketInputStream to another. This is a low level copy that copies byte for byte the packet data and re-writes the capture file record headers for potentially different format from the source stream.

Specified by:

copy in class PacketOutputStream

Parameters:

in - PacketInputStream to use as source of the copy operation.

Throws:

java.io.IOException - Any I/O errors.

StreamFormatException

main

public static void main(java.lang.String[] args)

Test function for CaptureOutputStream

Parameters:

args - command line arguments