Class AbstractPacket.AbstractHeader

java.lang.Object

org.pcap4j.packet.AbstractPacket.AbstractHeader

All Implemented Interfaces:

Serializable, Packet.Header

Direct Known Subclasses:

AbstractPppPacket.AbstractPppHeader, ArpPacket.ArpHeader, BsdLoopbackPacket.BsdLoopbackHeader, DnsPacket.DnsHeader, Dot11ManagementPacket.Dot11ManagementHeader, Dot1qVlanTagPacket.Dot1qVlanTagHeader, EthernetPacket.EthernetHeader, GtpV1Packet.GtpV1Header, IcmpIdentifiablePacket.IcmpIdentifiableHeader, IcmpV4CommonPacket.IcmpV4CommonHeader, IcmpV4DestinationUnreachablePacket.IcmpV4DestinationUnreachableHeader, IcmpV4ParameterProblemPacket.IcmpV4ParameterProblemHeader, IcmpV4RedirectPacket.IcmpV4RedirectHeader, IcmpV4SourceQuenchPacket.IcmpV4SourceQuenchHeader, IcmpV4TimeExceededPacket.IcmpV4TimeExceededHeader, IcmpV6CommonPacket.IcmpV6CommonHeader, IcmpV6DestinationUnreachablePacket.IcmpV6DestinationUnreachableHeader, IcmpV6HomeAgentAddressDiscoveryReplyPacket.IcmpV6HomeAgentAddressDiscoveryReplyHeader, IcmpV6HomeAgentAddressDiscoveryRequestPacket.IcmpV6HomeAgentAddressDiscoveryRequestHeader, IcmpV6MobilePrefixAdvertisementPacket.IcmpV6MobilePrefixAdvertisementHeader, IcmpV6MobilePrefixSolicitationPacket.IcmpV6MobilePrefixSolicitationHeader, IcmpV6NeighborAdvertisementPacket.IcmpV6NeighborAdvertisementHeader, IcmpV6NeighborSolicitationPacket.IcmpV6NeighborSolicitationHeader, IcmpV6PacketTooBigPacket.IcmpV6PacketTooBigHeader, IcmpV6ParameterProblemPacket.IcmpV6ParameterProblemHeader, IcmpV6RedirectPacket.IcmpV6RedirectHeader, IcmpV6RouterAdvertisementPacket.IcmpV6RouterAdvertisementHeader, IcmpV6RouterSolicitationPacket.IcmpV6RouterSolicitationHeader, IcmpV6TimeExceededPacket.IcmpV6TimeExceededHeader, IpV4Packet.IpV4Header, IpV6ExtFragmentPacket.IpV6ExtFragmentHeader, IpV6ExtOptionsPacket.IpV6ExtOptionsHeader, IpV6ExtRoutingPacket.IpV6ExtRoutingHeader, IpV6ExtUnknownPacket.IpV6ExtUnknownHeader, IpV6Packet.IpV6Header, LinuxSllPacket.LinuxSllHeader, LlcPacket.LlcHeader, RadiotapPacket.RadiotapHeader, SctpPacket.SctpHeader, SnapPacket.SnapHeader, Ssh2BinaryPacket.Ssh2BinaryHeader, Ssh2DebugPacket.Ssh2DebugHeader, Ssh2DisconnectPacket.Ssh2DisconnectHeader, Ssh2IgnorePacket.Ssh2IgnoreHeader, Ssh2KexDhInitPacket.Ssh2KexDhInitHeader, Ssh2KexDhReplyPacket.Ssh2KexDhReplyHeader, Ssh2KexInitPacket.Ssh2KexInitHeader, Ssh2NewKeysPacket.Ssh2NewKeysHeader, Ssh2ServiceAcceptPacket.Ssh2ServiceAcceptHeader, Ssh2ServiceRequestPacket.Ssh2ServiceRequestHeader, Ssh2UnimplementedPacket.Ssh2UnimplementedHeader, Ssh2VersionExchangePacket.Ssh2VersionExchangeHeader, TcpPacket.TcpHeader, UdpPacket.UdpHeader

Enclosing class:

AbstractPacket

public abstract static class AbstractPacket.AbstractHeader
extends Object
implements Packet.Header

Abstract immutable header class.

Since:

pcap4j 0.9.1

Version:

pcap4j 0.9.1

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
private final LazyValue<Integer>	hashCodeCache
private final LazyValue<String>	hexStringCache
private final LazyValue<Integer>	lengthCache
private final LazyValue<byte[]>	rawDataCache
private static final long	serialVersionUID
private final LazyValue<String>	stringCache

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractHeader()

Method Summary

Modifier and Type	Method	Description
protected String	buildHexString()	This method builds the value toHexString() will return using the return value of getRawData().
protected byte[]	buildRawData()	This method builds the value getRawData() will return by concatenating the byte arrays in the list getRawFields() returns.
protected String	buildString()	This method builds the value toString() will return.
protected int	calcHashCode()	This method builds the value hashCode() will return using the byte array getRawData() returns.
protected int	calcLength()	This method calculates the value length() will return by adding up the lengths of byte arrays in the list getRawFields() returns.
boolean	equals(Object obj)	Indicates whether some other object is "equal to" this one using return values of getRawData().
byte[]	getRawData()	Returns this header's raw data.
protected abstract List<byte[]>	getRawFields()	Returns a list of byte arrays which represents this header's fields.
int	hashCode()	Returns a hash code value for the object.
int	length()	Returns the header length in bytes.
String	toHexString()	Returns the hex string representation of this object.
String	toString()	Returns a string representation of the object.

Methods inherited from class Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details

serialVersionUID

private static final long serialVersionUID

See Also:

• Constant Field Values

lengthCache

private final LazyValue<Integer> lengthCache

rawDataCache

private final LazyValue<byte[]> rawDataCache

hexStringCache

private final LazyValue<String> hexStringCache

stringCache

private final LazyValue<String> stringCache

hashCodeCache

private final LazyValue<Integer> hashCodeCache

Constructor Details

AbstractHeader

protected AbstractHeader()

Method Details

getRawFields

protected abstract List<byte[]> getRawFields()

Returns a list of byte arrays which represents this header's fields. This method is called by calcLength() and buildRawData().

Returns:

a list of byte arrays which represents this header's fields

calcLength

protected int calcLength()

This method calculates the value length() will return by adding up the lengths of byte arrays in the list getRawFields() returns.

Returns:

a calculated length

length

public int length()

Returns the header length in bytes. This method calls calcLength() and caches the return value when it is called for the first time, and then, this method returns the cached value from the second time.

Specified by:

length in interface Packet.Header

Returns:

the length of the byte stream of the header represented by this object in bytes

buildRawData

protected byte[] buildRawData()

This method builds the value getRawData() will return by concatenating the byte arrays in the list getRawFields() returns.

Returns:

a raw data built

getRawData

public byte[] getRawData()

Returns this header's raw data. This method calls buildRawData() and caches the return value when it is called for the first time, and then, this method returns the cached value from the second time. More correctly, this method returns a copy of the cached value, so that the cache can't be changed.

Specified by:

getRawData in interface Packet.Header

Returns:

the raw data of this packet's header, namely a piece of the byte stream which is actually sent through real network

buildHexString

protected String buildHexString()

This method builds the value toHexString() will return using the return value of getRawData(). Each octet in this return value is separated by a white space. (e.g. 00 01 02 03 aa bb cc)

Returns:

a hex string representation of this object

toHexString

public String toHexString()

Returns the hex string representation of this object. This method calls buildHexString() and caches the return value when it is called for the first time, and then, this method returns the cached value from the second time.

Returns:

a hex string representation of this object

buildString

protected String buildString()

This method builds the value toString() will return.

Returns:

a string representation of this object

toString

public String toString()

Returns a string representation of the object. This method calls buildString() and caches the return value when it is called for the first time, and then, this method returns the cached value from the second time.

Overrides:

toString in class Object

equals

public boolean equals(Object obj)

Indicates whether some other object is "equal to" this one using return values of getRawData(). This method should be overridden so that it does more strict comparisons more efficiently.

Overrides:

equals in class Object

calcHashCode

protected int calcHashCode()

This method builds the value hashCode() will return using the byte array getRawData() returns. This method may be better to be overridden for performance reason.

Returns:

a calculated hash code value for the object

hashCode

public int hashCode()

Returns a hash code value for the object. This method calls calcHashCode() and caches the return value when it is called for the first time, and then, this method returns the cached value from the second time.

Overrides:

hashCode in class Object