io.netty.handler.codec.dns

Class DnsHeader

java.lang.Object

io.netty.handler.codec.dns.DnsHeader

Direct Known Subclasses:

DnsQueryHeader, DnsResponseHeader

public class DnsHeader
extends Object

The header super-class which includes information shared by DNS query and response packet headers such as the ID, opcode, and type. The only flag shared by both classes is the flag for desiring recursion.

Field Summary

Fields

Modifier and Type	Field and Description
static int	OPCODE_IQUERY Deprecated.
static int	OPCODE_QUERY Message is for a standard query.
static int	TYPE_QUERY Message type is query.
static int	TYPE_RESPONSE Message type is response.

Method Summary

Methods

Modifier and Type	Method and Description
int	additionalResourceCount() Returns the number of additional resource records in the DnsMessage.
int	answerCount() Returns the number of answer resource records in the DnsMessage.
int	authorityResourceCount() Returns the number of authority resource records in the DnsMessage.
int	id() Returns the 2 byte unsigned identifier number used for the DnsMessage.
boolean	isRecursionDesired() Returns true if a query is to be pursued recursively.
int	opcode() Returns the 4 bit opcode used for the DnsMessage.
int	questionCount() Returns the number of questions in the DnsMessage.
DnsHeader	setId(int id) Sets the id for this DnsMessage.
DnsHeader	setOpcode(int opcode) Sets the opcode for this DnsMessage.
DnsHeader	setRecursionDesired(boolean recursionDesired) Sets whether a name server is directed to pursue a query recursively or not.
DnsHeader	setType(int type) Sets the DnsMessage type.
DnsHeader	setZ(int z) Sets the field Z.
int	type() Returns the type of DnsMessage.
int	z() Returns the 3 bit reserved field 'Z'.

Methods inherited from class java.lang.Object

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

Field Detail

TYPE_QUERY

public static final int TYPE_QUERY

Message type is query.

See Also:

Constant Field Values

TYPE_RESPONSE

public static final int TYPE_RESPONSE

Message type is response.

See Also:

Constant Field Values

OPCODE_QUERY

public static final int OPCODE_QUERY

Message is for a standard query.

See Also:

Constant Field Values

OPCODE_IQUERY

@Deprecated
public static final int OPCODE_IQUERY

Deprecated.

Message is for an inverse query. Note: inverse queries have been obsoleted since RFC 3425, and are not necessarily supported.

See Also:

Constant Field Values

Method Detail

questionCount

public int questionCount()

Returns the number of questions in the DnsMessage.

answerCount

public int answerCount()

Returns the number of answer resource records in the DnsMessage.

authorityResourceCount

public int authorityResourceCount()

Returns the number of authority resource records in the DnsMessage.

additionalResourceCount

public int additionalResourceCount()

Returns the number of additional resource records in the DnsMessage.

isRecursionDesired

public boolean isRecursionDesired()

Returns true if a query is to be pursued recursively.

opcode

public int opcode()

Returns the 4 bit opcode used for the DnsMessage.

See Also:

OPCODE_QUERY, OPCODE_IQUERY

type

public int type()

Returns the type of DnsMessage.

See Also:

TYPE_QUERY

id

public int id()

Returns the 2 byte unsigned identifier number used for the DnsMessage.

setOpcode

public DnsHeader setOpcode(int opcode)

Sets the opcode for this DnsMessage.

Parameters:

opcode - opcode to set

Returns:

the header to allow method chaining

setRecursionDesired

public DnsHeader setRecursionDesired(boolean recursionDesired)

Sets whether a name server is directed to pursue a query recursively or not.

Parameters:

recursionDesired - if set to true, pursues query recursively

Returns:

the header to allow method chaining

setType

public DnsHeader setType(int type)

Sets the DnsMessage type.

Parameters:

type - message type

Returns:

the header to allow method chaining

setId

public DnsHeader setId(int id)

Sets the id for this DnsMessage.

Parameters:

id - a unique 2 byte unsigned identifier

Returns:

the header to allow method chaining

z

public int z()

Returns the 3 bit reserved field 'Z'.

setZ

public DnsHeader setZ(int z)

Sets the field Z. This field is reserved and should remain as 0 if the DNS server does not make usage of this field.

Parameters:

z - the value for the reserved field Z