Package org.minidns.dnsname

Class DnsName

java.lang.Object

org.minidns.dnsname.DnsName

All Implemented Interfaces:

Serializable, CharSequence, Comparable<DnsName>

public final class DnsName
extends Object
implements CharSequence, Serializable, Comparable<DnsName>

A DNS name, also called "domain name". A DNS name consists of multiple 'labels' and is subject to certain restrictions (see for example RFC 3696 § 2.).

Instances of this class can be created by using from(String).

This class holds three representations of a DNS name: ACE, raw ACE and IDN. ACE (ASCII Compatible Encoding), which can be accessed via ace, represents mostly the data that got send over the wire. But since DNS names are case insensitive, the ACE value is normalized to lower case. You can use getRawAce() to get the raw ACE data that was received, which possibly includes upper case characters. The IDN (Internationalized Domain Name), that is the DNS name as it should be shown to the user, can be retrieved using asIdn().

More information about Internationalized Domain Names can be found at:

• UTS #46 - Unicode IDNA Compatibility Processing
• RFC 8753 - Internationalized Domain Names for Applications (IDNA) Review for New Unicode Versions

Author:

Florian Schmaus

See Also:

RFC 3696, Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
String	ace	The DNS name in ASCII Compatible Encoding (ACE).
static DnsName	IN_ADDR_ARPA
static DnsName	IP6_ARPA
(package private) static int	MAX_DNSNAME_LENGTH_IN_OCTETS
static int	MAX_LABELS
static DnsName	ROOT
static boolean	VALIDATE	Whether or not the DNS name is validated on construction.

Method Summary

Modifier and Type	Method	Description
String	asIdn()
char	charAt(int index)
int	compareTo(DnsName other)
boolean	equals(Object other)
static DnsName	from(CharSequence name)
static DnsName	from(String name)
static DnsName	from(String[] parts)
static DnsName	from(DnsLabel grandchild, DnsLabel child, DnsName parent)
static DnsName	from(DnsLabel child, DnsName parent)
static DnsName	from(DnsName... nameComponents)
static DnsName	from(DnsName child, DnsName parent)	Create a DNS name by "concatenating" the child under the parent name.
byte[]	getBytes()	Serialize a domain name under IDN rules.
String	getDomainpart()	Domainpart in ACE representation.
String	getHostpart()	Hostpart in ACE representation.
DnsLabel	getHostpartLabel()
DnsLabel	getLabel(int labelNum)
int	getLabelCount()
DnsLabel[]	getLabels()	Get a copy of the labels of this DNS name.
DnsName	getParent()	Return the parent of this DNS label.
String	getRawAce()
byte[]	getRawBytes()
DnsLabel[]	getRawLabels()	Get a copy of the raw labels of this DNS name.
int	hashCode()
boolean	isChildOf(DnsName parent)
boolean	isDirectChildOf(DnsName parent)
boolean	isRootLabel()
int	length()
static DnsName	parse(DataInputStream dis, byte[] data)	Parse a domain name starting at the current offset and moving the input stream pointer past this domain name (even if cross references occure).
int	size()
DnsName	stripToLabels(int labelCount)
CharSequence	subSequence(int start, int end)
String	toString()
void	writeToStream(OutputStream os)

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.CharSequence

chars, codePoints

Field Detail

MAX_DNSNAME_LENGTH_IN_OCTETS

static final int MAX_DNSNAME_LENGTH_IN_OCTETS

See Also:

RFC 1035 § 2.3.4., Constant Field Values

MAX_LABELS

public static final int MAX_LABELS

See Also:

Constant Field Values

ROOT

public static final DnsName ROOT

IN_ADDR_ARPA

public static final DnsName IN_ADDR_ARPA

IP6_ARPA

public static final DnsName IP6_ARPA

VALIDATE

public static boolean VALIDATE

Whether or not the DNS name is validated on construction.

ace

public final String ace

The DNS name in ASCII Compatible Encoding (ACE).

Method Detail

writeToStream

public void writeToStream(OutputStream os)
                   throws IOException

Throws:

IOException

getBytes

public byte[] getBytes()

Serialize a domain name under IDN rules.

Returns:

The binary domain name representation.

getRawBytes

public byte[] getRawBytes()

getRawAce

public String getRawAce()

asIdn

public String asIdn()

getDomainpart

public String getDomainpart()

Domainpart in ACE representation.

Returns:

the domainpart in ACE representation.

getHostpart

public String getHostpart()

Hostpart in ACE representation.

Returns:

the hostpart in ACE representation.

getHostpartLabel

public DnsLabel getHostpartLabel()

size

public int size()

length

public int length()

Specified by:

length in interface CharSequence

charAt

public char charAt(int index)

Specified by:

charAt in interface CharSequence

subSequence

public CharSequence subSequence(int start,
                                int end)

Specified by:

subSequence in interface CharSequence

toString

public String toString()

Specified by:

toString in interface CharSequence

Overrides:

toString in class Object

from

public static DnsName from(CharSequence name)

from

public static DnsName from(String name)

from

public static DnsName from(DnsName child,
                           DnsName parent)

Create a DNS name by "concatenating" the child under the parent name. The child can also be seen as the "left" part of the resulting DNS name and the parent is the "right" part.

For example using "i.am.the.child" as child and "of.this.parent.example" as parent, will result in a DNS name: "i.am.the.child.of.this.parent.example".

Parameters:

child - the child DNS name.

parent - the parent DNS name.

Returns:

the resulting of DNS name.

from

public static DnsName from(DnsLabel child,
                           DnsName parent)

from

public static DnsName from(DnsLabel grandchild,
                           DnsLabel child,
                           DnsName parent)

from

public static DnsName from(DnsName... nameComponents)

from

public static DnsName from(String[] parts)

parse

public static DnsName parse(DataInputStream dis,
                            byte[] data)
                     throws IOException

Parse a domain name starting at the current offset and moving the input stream pointer past this domain name (even if cross references occure).

Parameters:

dis - The input stream.

data - The raw data (for cross references).

Returns:

The domain name string.

Throws:

IOException - Should never happen.

compareTo

public int compareTo(DnsName other)

Specified by:

compareTo in interface Comparable<DnsName>

equals

public boolean equals(Object other)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

isDirectChildOf

public boolean isDirectChildOf(DnsName parent)

isChildOf

public boolean isChildOf(DnsName parent)

getLabelCount

public int getLabelCount()

getLabels

public DnsLabel[] getLabels()

Get a copy of the labels of this DNS name. The resulting array will contain the labels in reverse order, that is, the top-level domain will be at res[0].

Returns:

an array of the labels in reverse order.

getLabel

public DnsLabel getLabel(int labelNum)

getRawLabels

public DnsLabel[] getRawLabels()

Get a copy of the raw labels of this DNS name. The resulting array will contain the labels in reverse order, that is, the top-level domain will be at res[0].

Returns:

an array of the raw labels in reverse order.

stripToLabels

public DnsName stripToLabels(int labelCount)

getParent

public DnsName getParent()

Return the parent of this DNS label. Will return the root label if this label itself is the root label (because there is no parent of root).

For example:

• "foo.bar.org".getParent() == "bar.org"
• ".".getParent() == "."

Returns:

the parent of this DNS label.

isRootLabel

public boolean isRootLabel()