InetAddress

See also:

• getByAddress(byte[])
• getByAddress(java.lang.String, byte[])
• getAllByName(java.lang.String)
• getByName(java.lang.String)
• getLocalHost()

equals

public boolean equals (Object obj)

Compares this object against the specified object. The result is true if and only if the argument is not null and it represents the same IP address as this object.

Two instances of InetAddress represent the same IP address if the length of the byte arrays returned by getAddress is the same for both, and each of the array components is the same for the byte arrays.

getAddress

public byte[] getAddress ()

Returns the raw IP address of this InetAddress object. The result is in network byte order: the highest order byte of the address is in getAddress()[0].

getAllByName

public static InetAddress[] getAllByName (String host)

Given the name of a host, returns an array of its IP addresses, based on the configured name service on the system.

The host name can either be a machine name, such as "java.sun.com", or a textual representation of its IP address. If a literal IP address is supplied, only the validity of the address format is checked.

For host specified in literal IPv6 address, either the form defined in RFC 2732 or the literal IPv6 address format defined in RFC 2373 is accepted. A literal IPv6 address may also be qualified by appending a scoped zone identifier or scope_id. The syntax and usage of scope_ids is described here.

If the host is null then an InetAddress representing an address of the loopback interface is returned. See RFC 3330 section 2 and RFC 2373 section 2.5.3.

If there is a security manager and host is not null and host.length() is not equal to zero, the security manager's checkConnect method is called with the hostname and -1 as its arguments to see if the operation is allowed.

getByAddress

public static InetAddress getByAddress (byte[] addr)

Returns an InetAddress object given the raw IP address . The argument is in network byte order: the highest order byte of the address is in getAddress()[0].

This method doesn't block, i.e. no reverse name service lookup is performed.

IPv4 address byte array must be 4 bytes long and IPv6 byte array must be 16 bytes long

getByAddress

public static InetAddress getByAddress (String host, 
                byte[] addr)

Creates an InetAddress based on the provided host name and IP address. No name service is checked for the validity of the address.

The host name can either be a machine name, such as "java.sun.com", or a textual representation of its IP address.

No validity checking is done on the host name either.

If addr specifies an IPv4 address an instance of Inet4Address will be returned; otherwise, an instance of Inet6Address will be returned.

IPv4 address byte array must be 4 bytes long and IPv6 byte array must be 16 bytes long

getByName

public static InetAddress getByName (String host)

Determines the IP address of a host, given the host's name.

The host name can either be a machine name, such as "java.sun.com", or a textual representation of its IP address. If a literal IP address is supplied, only the validity of the address format is checked.

For host specified in literal IPv6 address, either the form defined in RFC 2732 or the literal IPv6 address format defined in RFC 2373 is accepted. IPv6 scoped addresses are also supported. See here for a description of IPv6 scoped addresses.

If the host is null then an InetAddress representing an address of the loopback interface is returned. See RFC 3330 section 2 and RFC 2373 section 2.5.3.

getCanonicalHostName

public String getCanonicalHostName ()

Gets the fully qualified domain name for this IP address. Best effort method, meaning we may not be able to return the FQDN depending on the underlying system configuration.

If there is a security manager, this method first calls its checkConnect method with the hostname and -1 as its arguments to see if the calling code is allowed to know the hostname for this IP address, i.e., to connect to the host. If the operation is not allowed, it will return the textual representation of the IP address.

getHostAddress

public String getHostAddress ()

Returns the IP address string in textual presentation.

getHostName

public String getHostName ()

Gets the host name for this IP address.

If this InetAddress was created with a host name, this host name will be remembered and returned; otherwise, a reverse name lookup will be performed and the result will be returned based on the system configured name lookup service. If a lookup of the name service is required, call getCanonicalHostName.

If there is a security manager, its checkConnect method is first called with the hostname and -1 as its arguments to see if the operation is allowed. If the operation is not allowed, it will return the textual representation of the IP address.

getLocalHost

public static InetAddress getLocalHost ()

Returns the address of the local host. This is achieved by retrieving the name of the host from the system, then resolving that name into an InetAddress.

Note: The resolved address may be cached for a short period of time.

If there is a security manager, its checkConnect method is called with the local host name and -1 as its arguments to see if the operation is allowed. If the operation is not allowed, an InetAddress representing the loopback address is returned.

getLoopbackAddress

public static InetAddress getLoopbackAddress ()

Returns the loopback address.

The InetAddress returned will represent the IPv4 loopback address, 127.0.0.1, or the IPv6 loopback address, ::1. The IPv4 loopback address returned is only one of many in the form 127.*.*.*

hashCode

public int hashCode ()

Returns a hashcode for this IP address.

isAnyLocalAddress

public boolean isAnyLocalAddress ()

Utility routine to check if the InetAddress in a wildcard address.

isLinkLocalAddress

public boolean isLinkLocalAddress ()

Utility routine to check if the InetAddress is an link local address.

isLoopbackAddress

public boolean isLoopbackAddress ()

Utility routine to check if the InetAddress is a loopback address.

isMCGlobal

public boolean isMCGlobal ()

Utility routine to check if the multicast address has global scope.

isMCLinkLocal

public boolean isMCLinkLocal ()

Utility routine to check if the multicast address has link scope.

isMCNodeLocal

public boolean isMCNodeLocal ()

Utility routine to check if the multicast address has node scope.

isMCOrgLocal

public boolean isMCOrgLocal ()

Utility routine to check if the multicast address has organization scope.

isMCSiteLocal

public boolean isMCSiteLocal ()

Utility routine to check if the multicast address has site scope.

isMulticastAddress

public boolean isMulticastAddress ()

Utility routine to check if the InetAddress is an IP multicast address.

isReachable

public boolean isReachable (int timeout)

Test whether that address is reachable. Best effort is made by the implementation to try to reach the host, but firewalls and server configuration may block requests resulting in a unreachable status while some specific ports may be accessible.

Android implementation attempts ICMP ECHO REQUESTs first, on failure it will fall back to TCP ECHO REQUESTs. Success on either protocol will return true.

The timeout value, in milliseconds, indicates the maximum amount of time the try should take. If the operation times out before getting an answer, the host is deemed unreachable. A negative value will result in an IllegalArgumentException being thrown.

isReachable

public boolean isReachable (NetworkInterface netif, 
                int ttl, 
                int timeout)

Test whether that address is reachable. Best effort is made by the implementation to try to reach the host, but firewalls and server configuration may block requests resulting in a unreachable status while some specific ports may be accessible.

Android implementation attempts ICMP ECHO REQUESTs first, on failure it will fall back to TCP ECHO REQUESTs. Success on either protocol will return true.

The network interface and ttl parameters let the caller specify which network interface the test will go through and the maximum number of hops the packets should go through. A negative value for the ttl will result in an IllegalArgumentException being thrown.

The timeout value, in milliseconds, indicates the maximum amount of time the try should take. If the operation times out before getting an answer, the host is deemed unreachable. A negative value will result in an IllegalArgumentException being thrown.

isSiteLocalAddress

public boolean isSiteLocalAddress ()

Utility routine to check if the InetAddress is a site local address.

toString

public String toString ()

Converts this IP address to a String. The string returned is of the form: hostname / literal IP address. If the host name is unresolved, no reverse name service lookup is performed. The hostname part will be represented by an empty string.