This class represents an Internet Protocol (IP) address. The class does not have a public constructor but instead supports static factory methods for obtaining InetAddress objects. getLocalHost( ) returns the InetAddress of the local computer. getByName( ) returns the InetAddress of a host specified by name. getAllByName( ) returns an array of InetAddress objects that represents all the available addresses for a host specified by name. getByAddress( ) returns an InetAddress that represents the IP address defined by the specified array of bytes.

Once you have obtained an InetAddress object, its instance methods provide various sorts of information about it. Two of the most important are getHostName( ) , which returns the hostname, and getAddress( ), which returns the IP address as an array of bytes, with the highest-order byte as the first element of the array. getHostAddress( ) returns the IP address formatted as a string rather than as an array of bytes. The various methods whose names begin with "is" determine whether the address falls into any of the named categories. The "isMC" methods are all related to multicast addresses.

This class was originally defined in Java 1.0, but many of its methods were added in Java 1.4. Java 1.4 also defined two subclasses, Inet4Address and Inet6Address representing IPv4 and IPv6 (version 4 and version 6) addresses. Java 5.0 adds isReachable( ) for testing whether the address describes a reachable (and responsive) host.

Figure 12-8. java.net.InetAddress

public class InetAddress implements Serializable {
// No Constructor
// Public Class Methods
     public static InetAddress[ ] getAllByName(String host) throws UnknownHostException;  
1.4  public static InetAddress getByAddress(byte[ ] addr) 
throws UnknownHostException;  
1.4  public static InetAddress getByAddress(String host, byte[ ] addr) throws UnknownHostException;  
     public static InetAddress getByName(String host) throws UnknownHostException;  
     public static InetAddress getLocalHost( ) throws UnknownHostException;  
// Public Instance Methods
     public byte[ ] getAddress( );            constant
1.4  public String getCanonicalHostName( ); 
     public String getHostAddress( );                constant
     public String getHostName( ); 
1.4  public boolean isAnyLocalAddress( );        constant
1.4  public boolean isLinkLocalAddress( );       constant
1.4  public boolean isLoopbackAddress( );        constant
1.4  public boolean isMCGlobal( );               constant
1.4  public boolean isMCLinkLocal( );            constant
1.4  public boolean isMCNodeLocal( );            constant
1.4  public boolean isMCOrgLocal( );             constant
1.4  public boolean isMCSiteLocal( );            constant
1.1  public boolean isMulticastAddress( );       constant
5.0  public boolean isReachable(int timeout) throws java.io.IOException; 
5.0  public boolean isReachable(NetworkInterface netif, int ttl, int timeout) 
throws java.io.IOException;  
1.4  public boolean isSiteLocalAddress( );       constant
// Public Methods Overriding Object
     public boolean equals(Object obj);            constant
     public int hashCode( );                         constant
     public String toString( );
}

Subclasses

Inet4Address, Inet6Address

Passed To

Too many methods to list.

Returned By

Authenticator.getRequestingSite( ), DatagramPacket.getAddress( ), DatagramSocket.{getInetAddress( ), getLocalAddress( )}, InetSocketAddress.getAddress( ), MulticastSocket.getInterface( ), ServerSocket.getInetAddress( ), Socket.{getInetAddress( ), getLocalAddress( )}, SocketImpl.getInetAddress( ), URLStreamHandler.getHostAddress( ), javax.security.auth.kerberos.KerberosTicket.getClientAddresses( )

Type Of

SocketImpl.address