Package org.xbill.DNS

Class Name

java.lang.Object
org.xbill.DNS.Name
All Implemented Interfaces:
Serializable, Comparable<Name>
public class Name extends Object implements Comparable<Name>, Serializable
A representation of a domain name. It may either be absolute (fully qualified) or relative.
Author:
Brian Wellington
See Also:

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final Name
    empty
    The root name
    static final Name
    root
    The root name

  • Constructor Summary

    Constructors
    Constructor
    Description
    Name(byte[] b)
    Create a new name from DNS wire format
    Name(String s)
    Create a new name from a string.
    Name(String s, Name origin)
    Create a new name from a string and an origin.
    Name(DNSInput in)
    Create a new name from DNS a wire format message
    Name(Name src, int n)
    Create a new name by removing labels from the beginning of an existing Name

  • Method Summary

    Modifier and Type
    Method
    Description
    Name
    canonicalize()
    Returns a canonicalized version of the Name (all lowercase).
    int
    compareTo(Name arg)
    Compares this Name to another Object.
    static Name
    concatenate(Name prefix, Name suffix)
    Creates a new name by concatenating two existing names.
    boolean
    equals(Object arg)
    Are these two Names equivalent?
    static Name
    fromConstantString(String s)
    Create a new name from a constant string.
    Name
    fromDNAME(DNAMERecord dname)
    Generates a new Name to be used when following a DNAME.
    static Name
    fromString(String s)
    Create a new name from a string.
    static Name
    fromString(String s, Name origin)
    Create a new name from a string and an origin.
    byte[]
    getLabel(int n)
    Retrieve the nth label of a Name.
    String
    getLabelString(int n)
    Convert the nth label in a Name to a String
    int
    hashCode()
    Computes a hashcode based on the value
    boolean
    isAbsolute()
    Is this name absolute?
    boolean
    isWild()
    Is this name a wildcard?
    int
    labels()
    The number of labels in the name.
    short
    length()
    The length of the name (in bytes).
    Name
    relativize(Name origin)
    If this name is a subdomain of origin, return a new name relative to origin with the same value.
    boolean
    subdomain(Name domain)
    Returns true if this Name a subdomain of domain.
    String
    toString()
    Convert a Name to a String
    String
    toString(boolean omitFinalDot)
    Convert a Name to a String
    byte[]
    toWire()
    Emit a Name in DNS wire format
    void
    toWire(DNSOutput out, Compression c)
    Emit a Name in DNS wire format
    void
    toWire(DNSOutput out, Compression c, boolean canonical)
    Emit a Name in DNS wire format
    byte[]
    toWireCanonical()
    Emit a Name in canonical DNS wire format (all lowercase)
    void
    toWireCanonical(DNSOutput out)
    Emit a Name in canonical DNS wire format (all lowercase)
    Name
    wild(int n)
    Generates a new Name with the first n labels replaced by a wildcard

    Methods inherited from class java.lang.Object

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

  • Field Details

    • root

      public static final Name root
      The root name

    • empty

      public static final Name empty
      The root name

  • Constructor Details

    • Name

      public Name(String s, Name origin) throws TextParseException
      Create a new name from a string and an origin. This does not automatically make the name absolute; it will be absolute if it has a trailing dot or an absolute origin is appended.
      Parameters:
      s - The string to be converted
      origin - If the name is not absolute, the origin to be appended.
      Throws:
      TextParseException - The name is invalid.

    • Name

      public Name(String s) throws TextParseException
      Create a new name from a string. This does not automatically make the name absolute; it will be absolute if it has a trailing dot.
      Parameters:
      s - The string to be converted
      Throws:
      TextParseException - The name is invalid.

    • Name

      public Name(DNSInput in) throws WireParseException
      Create a new name from DNS a wire format message
      Parameters:
      in - A stream containing the DNS message which is currently positioned at the start of the name to be read.
      Throws:
      WireParseException

    • Name

      public Name(byte[] b) throws IOException
      Create a new name from DNS wire format
      Parameters:
      b - A byte array containing the wire format of the name.
      Throws:
      IOException

    • Name

      public Name(Name src, int n)
      Create a new name by removing labels from the beginning of an existing Name
      Parameters:
      src - An existing Name
      n - The number of labels to remove from the beginning in the copy

  • Method Details

    • fromString

      public static Name fromString(String s, Name origin) throws TextParseException
      Create a new name from a string and an origin. This does not automatically make the name absolute; it will be absolute if it has a trailing dot or an absolute origin is appended. This is identical to the constructor, except that it will avoid creating new objects in some cases.
      Parameters:
      s - The string to be converted
      origin - If the name is not absolute, the origin to be appended.
      Throws:
      TextParseException - The name is invalid.

    • fromString

      public static Name fromString(String s) throws TextParseException
      Create a new name from a string. This does not automatically make the name absolute; it will be absolute if it has a trailing dot. This is identical to the constructor, except that it will avoid creating new objects in some cases.
      Parameters:
      s - The string to be converted
      Throws:
      TextParseException - The name is invalid.

    • fromConstantString

      public static Name fromConstantString(String s)
      Create a new name from a constant string. This should only be used when the name is known to be good - that is, when it is constant.
      Parameters:
      s - The string to be converted
      Throws:
      IllegalArgumentException - The name is invalid.

    • concatenate

      public static Name concatenate(Name prefix, Name suffix) throws NameTooLongException
      Creates a new name by concatenating two existing names. If the prefix name is absolute prefix is returned unmodified.
      Parameters:
      prefix - The prefix name. Must be relative.
      suffix - The suffix name.
      Returns:
      The concatenated name.
      Throws:
      NameTooLongException - The name is too long.

    • relativize

      public Name relativize(Name origin)
      If this name is a subdomain of origin, return a new name relative to origin with the same value. Otherwise, return the existing name.
      Parameters:
      origin - The origin to remove.
      Returns:
      The possibly relativized name.

    • wild

      public Name wild(int n)
      Generates a new Name with the first n labels replaced by a wildcard
      Returns:
      The wildcard name

    • canonicalize

      public Name canonicalize()
      Returns a canonicalized version of the Name (all lowercase). This may be the same name, if the input Name is already canonical.

    • fromDNAME

      public Name fromDNAME(DNAMERecord dname) throws NameTooLongException
      Generates a new Name to be used when following a DNAME.
      Parameters:
      dname - The DNAME record to follow.
      Returns:
      The constructed name or null if this Name is not a subdomain of the dname name.
      Throws:
      NameTooLongException - The resulting name is too long.

    • isWild

      public boolean isWild()
      Is this name a wildcard?

    • isAbsolute

      public boolean isAbsolute()
      Is this name absolute?

    • length

      public short length()
      The length of the name (in bytes).

    • labels

      public int labels()
      The number of labels in the name.

    • subdomain

      public boolean subdomain(Name domain)
      Returns true if this Name a subdomain of domain.

    • toString

      public String toString(boolean omitFinalDot)
      Convert a Name to a String
      Parameters:
      omitFinalDot - If true, and the name is absolute, omit the final dot.
      Returns:
      The representation of this name as a (printable) String.

    • toString

      public String toString()
      Convert a Name to a String
      Overrides:
      toString in class Object
      Returns:
      The representation of this name as a (printable) String.

    • getLabel

      public byte[] getLabel(int n)
      Retrieve the nth label of a Name. This makes a copy of the label; changing this does not change the Name. The returned byte array includes the label length as the first byte.
      Parameters:
      n - The label to be retrieved. The first label is 0.

    • getLabelString

      public String getLabelString(int n)
      Convert the nth label in a Name to a String
      Parameters:
      n - The label to be converted to a (printable) String. The first label is 0.

    • toWire

      public void toWire(DNSOutput out, Compression c)
      Emit a Name in DNS wire format
      Parameters:
      out - The output stream containing the DNS message.
      c - The compression context, or null of no compression is desired.
      Throws:
      IllegalArgumentException - The name is not absolute.

    • toWire

      public byte[] toWire()
      Emit a Name in DNS wire format
      Throws:
      IllegalArgumentException - The name is not absolute.

    • toWireCanonical

      public void toWireCanonical(DNSOutput out)
      Emit a Name in canonical DNS wire format (all lowercase)
      Parameters:
      out - The output stream to which the message is written.

    • toWireCanonical

      public byte[] toWireCanonical()
      Emit a Name in canonical DNS wire format (all lowercase)
      Returns:
      The canonical form of the name.

    • toWire

      public void toWire(DNSOutput out, Compression c, boolean canonical)
      Emit a Name in DNS wire format
      Parameters:
      out - The output stream containing the DNS message.
      c - The compression context, or null of no compression is desired.
      canonical - If true, emit the name in canonicalized form (all lowercase).
      Throws:
      IllegalArgumentException - The name is not absolute.

    • equals

      public boolean equals(Object arg)
      Are these two Names equivalent?
      Overrides:
      equals in class Object

    • hashCode

      public int hashCode()
      Computes a hashcode based on the value
      Overrides:
      hashCode in class Object

    • compareTo

      public int compareTo(Name arg)
      Compares this Name to another Object.
      Specified by:
      compareTo in interface Comparable<Name>
      Parameters:
      arg - The name to be compared.
      Returns:
      The value 0 if the argument is a name equivalent to this name; a value less than 0 if the argument is less than this name in the canonical ordering, and a value greater than 0 if the argument is greater than this name in the canonical ordering.
      Throws:
      ClassCastException - if the argument is not a Name.