com.neeve.util

Class UtlNet

java.lang.Object

com.neeve.util.UtlNet

public final class UtlNet
extends Object

Utility class related to network and network addresses

This class MAY be used by end users, however it is not supported.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	UtlNet.DebugTracer

Constructor Summary

Constructors

Constructor and Description
UtlNet()

Method Summary

Methods

Modifier and Type	Method and Description
static String	formatNetworkInterfaceDescriptor(NetworkInterface nif) Returns a string describing a network interface (name + all bound addresses)
static NetworkInterface	getFirstActiveNetworkInterface(boolean multicastRequired) Find an active, non-virtual, non-loopback network device that might be appropriate as a primary device for general network communication and/or discovery.
static NetworkInterface	getFirstActiveNetworkInterface(UtlNet.DebugTracer tracer, boolean multicastRequired) Find an active, non-virtual, non-loopback network device that might be appropriate as a primary device for general network communication and/or discovery.
static InetAddress	getFirstInetAddress(NetworkInterface networkInterface) Given a NetworkInterface, returns the first InetAddress associated with the interface (prioritizing IPv4 over IPv6).
static String	getHostName(InetAddress address) Resolves the host name for the provided address.
static String	getLocalHostAddress() Get the local host address This method returns the local host address using the following: - InetAddress.getLocalHost().getHostAddress.
static String	getLocalHostAddressForDisplay(String defaultValue) Get the local host address for display purposes.
static InetAddress	getLocalHostInetAddress() Get the InetAddress representing the local host IP + hostname.
static String	getLocalHostName() Get the local host name This method returns the local host name using the following: - InetAddress.getLocalHost().getHostName.
static String	getLocalHostNameForDisplay(String defaultValue) Get the local host name for display purposes.
static String	inetAddrToName(String addr) Get a host name corresponding to a inet network address.
static boolean	isAddressLocal(InetAddress addr) Tests if a given address is local to current host.

Methods inherited from class java.lang.Object

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

Constructor Detail

UtlNet

public UtlNet()

Method Detail

inetAddrToName

public static final String inetAddrToName(String addr)

Get a host name corresponding to a inet network address.

Parameters:

addr - The textual representation of the inet network address.

Throws:

IllegalArgumentException - Thrown in case the user has either supplied an inet address in the incorrect format or has provided a host name that cannot be resolved to an IP address.

This method resolves a textual representation of an inet address to its host name. In case a host name is provided in the addr parameter, this method will attempt to resolve the name to an IP address and then resolve it back to the host name.

Threading:

This method is safe for concurrent access by multiple threads

getHostName

public static final String getHostName(InetAddress address)

Resolves the host name for the provided address.

Parameters:

address - The address whose host name to look up.

Returns:

The resolved host name.

getFirstActiveNetworkInterface

public static final NetworkInterface getFirstActiveNetworkInterface(boolean multicastRequired)
                                                             throws SocketException

Find an active, non-virtual, non-loopback network device that might be appropriate as a primary device for general network communication and/or discovery. This is useful when we need to determine a local IP address or hostname when one is not explicitly specified.

Parameters:

multicastRequired - indicates whether the returned network interface must support multicast

Returns:

the network device, or null if no suitable network device could be found

Throws:

SocketException - if there is an error getting the list of candidate network devices

Threading:

This method is safe for concurrent access by multiple threads

getFirstActiveNetworkInterface

public static final NetworkInterface getFirstActiveNetworkInterface(UtlNet.DebugTracer tracer,
                                              boolean multicastRequired)
                                                             throws SocketException

Find an active, non-virtual, non-loopback network device that might be appropriate as a primary device for general network communication and/or discovery. This is useful when we need to determine a local IP address or hostname when one is not explicitly specified.

Parameters:

multicastRequired - indicates whether the returned network interface must support multicast

tracer - the tracer to use for logging, may be null if no logging is required

Returns:

the network device, or null if no suitable network device could be found

Throws:

SocketException - if there is an error getting the list of candidate network devices

Threading:

This method is safe for concurrent access by multiple threads

getFirstInetAddress

public static final InetAddress getFirstInetAddress(NetworkInterface networkInterface)

Given a NetworkInterface, returns the first InetAddress associated with the interface (prioritizing IPv4 over IPv6).

Parameters:

networkInterface - The network interface to inspect

Returns:

The first matching InetAddress, or null if no appropriate address is found

formatNetworkInterfaceDescriptor

public static final String formatNetworkInterfaceDescriptor(NetworkInterface nif)

Returns a string describing a network interface (name + all bound addresses)

isAddressLocal

public static boolean isAddressLocal(InetAddress addr)

Tests if a given address is local to current host.

Parameters:

addr - The address to test.

Returns:

True if this is a local address

getLocalHostInetAddress

public static final InetAddress getLocalHostInetAddress()
                                                 throws UnknownHostException

Get the InetAddress representing the local host IP + hostname.

Throws:

UnknownHostException - Thrown if a local InetAddress could not be determined.

Threading:

This method is safe for concurrent access by multiple threads.

getLocalHostNameForDisplay

public static final String getLocalHostNameForDisplay(String defaultValue)

Get the local host name for display purposes.

Parameters:

defaultValue - The value to return if a local host name could not be determined.

This method returns the name of the local host machine on which the X process is running. The defaultValue is returned if the local host name could not be determined for whatever reason

Threading:

This method is safe for concurrent access by multiple threads.

getLocalHostName

public static final String getLocalHostName()
                                     throws UnknownHostException

Get the local host name

This method returns the local host name using the following:
- InetAddress.getLocalHost().getHostName.
If a host name could not be determined, then this method throws an UnknownHostException exception.

Throws:

UnknownHostException - Thrown if the local host name could not be determined via InetAddress.getLocalHost().getHostName

Threading:

This method is safe for concurrent access by multiple threads.

getLocalHostAddressForDisplay

public static final String getLocalHostAddressForDisplay(String defaultValue)

Get the local host address for display purposes.

Parameters:

defaultValue - The value to return if a local host address could not be determined.

This method returns the address of the local host machine on which the X process is running as returned by InetAddress.getLocalHost().getHostAddress. The defaultValue is returned if the local host address could not be determined for whatever reason

Threading:

This method is safe for concurrent access by multiple threads.

getLocalHostAddress

public static final String getLocalHostAddress()
                                        throws UnknownHostException

Get the local host address

This method returns the local host address using the following:
- InetAddress.getLocalHost().getHostAddress.
If a host address could not be determined, then this method throws an UnknownHostException exception.

Throws:

UnknownHostException - Thrown if the local host address could not be determined via InetAddress.getLocalHost().getHostAddress

Threading:

This method is safe for concurrent access by multiple threads.