org.jnetstream.packet
Interface Header

All Superinterfaces:

HeaderElement, java.lang.Iterable<HeaderElement>, com.slytechs.utils.namespace.Named

All Known Subinterfaces:

FiniteHeader

All Known Implementing Classes:

DataHeader, NullHeader

public interface Header
extends HeaderElement, java.lang.Iterable<HeaderElement>

Super interface of all headers contained within a packet. Each packet contans 0 or more protocol specific headers that are typically daisy chained. The header are part of the packet data as returned by live packet capture or as read from a capture/trace file.

This header interface does not provide any mutable methods outside of returning a mutable ByteBuffer with the header's content. The reason for this is that the header structure is built based upon the contents of the buffer and the header's NPL definition. If the header's contents have been modified structurally the entire has to be redecoded again.

The interface does not provide any methods with dealing with fields within this header or sub headers if they exist. You use the type specific header interface to check for existance of fields and sub headers and then access those fields and sub headers.

Author:

Mark Bednarczyk, Sly Technologies, Inc.

Nested Class Summary

static class	Header.DynamicProperty Common properties found in every header that are dynamic.
static class	Header.StaticProperty Constants which define various automatic and user defined properties.

Nested classes/interfaces inherited from interface com.slytechs.utils.namespace.Named

com.slytechs.utils.namespace.Named.Util

Method Summary

Field<?>[]	getAllFields()
Header[]	getAllHeaders()
com.slytechs.utils.memory.BitBuffer	getBuffer() Returns buffer containing the header's data.
<T> Field<T>	getField(DataField field) Retrieves field's runtime environment.
int	getLength() Returns the length of this header in bytes.
java.lang.String	getName() Returns the NPL name of this header.
int	getOffset() Position or offset from the start of the packet buffer this buffer belongs to.
<T> T	getProperty(Header.DynamicProperty key)
<T> T	getProperty(Header.StaticProperty key)
<T> T	getProperty(java.lang.String name)
Protocol	getProtocol()
java.lang.Class<? extends Header>	getType()
boolean	isTruncated() Tells if this header has been truncated or if all of the headers contents are contained within the packet buffer.

Methods inherited from interface org.jnetstream.packet.HeaderElement

getFieldConstant

Methods inherited from interface java.lang.Iterable

iterator

Method Detail

getName

java.lang.String getName()

Returns the NPL name of this header.

Specified by:

getName in interface com.slytechs.utils.namespace.Named

Returns:

name of this header

isTruncated

boolean isTruncated()
                    throws java.io.IOException

Tells if this header has been truncated or if all of the headers contents are contained within the packet buffer. Only what is considered as header content is included in this check as defined by the underlying NPL definition. Any data past the header content is not included in this check.

Returns:

true if header contents have been truncated and entire header could not be decoded, otherwise false

Throws:

java.io.IOException

getOffset

int getOffset()

Position or offset from the start of the packet buffer this buffer belongs to.

Returns:

0-based offset of the start of this header in octets from the beginning of the packet buffer

getLength

int getLength()

Returns the length of this header in bytes.

Returns:

number of octets this header occupies

getBuffer

com.slytechs.utils.memory.BitBuffer getBuffer()
                                              throws java.io.IOException

Returns buffer containing the header's data. The buffer is backed by the packet buffer which contains all of the contents of the packet. The returned buffer position, limit and capacity properties are set to getPosition(), getPosition() + getLength() and getPosition() + getLength() respectively. No new data is allocated and any changes to the returned header buffer are also reflected in the backing packet buffer.

Returns:

buffer which contains just the header data and is backed by the underlying packet buffer

Throws:

java.io.IOException

getField

<T> Field<T> getField(DataField field)
                  throws CodecException,
                         java.io.IOException

Retrieves field's runtime environment.

Type Parameters:

T - value type of the field

Parameters:

c - class of the field's runtime environment

Returns:

the runtime evironment of the field

Throws:

java.io.IOException

CodecException

getType

java.lang.Class<? extends Header> getType()

Returns:

getProperty

<T> T getProperty(Header.StaticProperty key)

Parameters:

key -

Returns:

getProperty

<T> T getProperty(Header.DynamicProperty key)

Parameters:

key -

Returns:

getProperty

<T> T getProperty(java.lang.String name)

Type Parameters:

T -

Parameters:

name -

Returns:

getProtocol

Protocol getProtocol()

Returns:

getAllFields

Field<?>[] getAllFields()

Returns:

getAllHeaders

Header[] getAllHeaders()

Returns: