ej.ecom.network

Class NetworkInterfaceManager

java.lang.Object

ej.ecom.network.NetworkInterfaceManager

public class NetworkInterfaceManager
extends java.lang.Object

A manager for the network interfaces. It allows to get the current IP configuration of a network interface and to reconfigure it.
It allows to enable/disable and start/stop an interface.
- Enable/disable is simply a logical state of the interface managed by software.
- Start/stop is more hardware-related. It may physically turn on/off the hardware module and it is intended to manage power consumption.


Scenario example: a system uses Ethernet as its main interface and 3G as its backup interface. In normal mode, Ethernet is started and enabled while 3G is stopped (and hence disabled) and communications all go through the Ethernet interface. When Ethernet loses Internet connection, it is disabled and 3G is started. Communications will then go through the 3G interface. When Ethernet gets Internet connection back, it is re-enabled, 3G is stopped and the system goes back to normal mode.

Constructor Summary

Constructors

Constructor and Description
NetworkInterfaceManager()

Method Summary

Modifier and Type	Method and Description
static void	configure(java.net.NetworkInterface netif, IPConfiguration conf) Sets the IP configuration of a network interface.
static void	disable(java.net.NetworkInterface netif) Disables a network interface (software side).
static void	enable(java.net.NetworkInterface netif) Enables a network interface (software side).
static IPConfiguration	getIPConfiguration(java.net.NetworkInterface netif) Gets the current IP configuration of a network interface.
static boolean	isEnabled(java.net.NetworkInterface netif) Tells whether a network interface is enabled or not.
static boolean	isStarted(java.net.NetworkInterface netif) Tells whether a network interface is started or not.
static void	setDefault(java.net.NetworkInterface netif) Set a network interface as default.
static void	start(java.net.NetworkInterface netif) Starts a network interface (hardware side).
static void	stop(java.net.NetworkInterface netif) Stops a network interface (hardware side).

Methods inherited from class java.lang.Object

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

Constructor Detail

NetworkInterfaceManager

public NetworkInterfaceManager()

Method Detail

configure

public static void configure(java.net.NetworkInterface netif,
                             IPConfiguration conf)
                      throws java.io.IOException

Sets the IP configuration of a network interface. The configuration may be sparse. Only not-null and relevant fields are applied. For instance, static IP address is ignored if DHCP is to be used. When the configuration is applied, be aware that:

• current communications may be interrupted, raising IOException,
• the hardware module associated to the network interface may reboot, making the interface not usable for a few seconds,
• it may take time to acquire an IP address if the configuration requires the use of DHCP, making the interface not usable for a few seconds.

Note that some DNS server addresses may be silently ignored if the underlying module doesn't support several DNS servers.

Parameters:

netif - the network interface.

conf - the network interface IP configuration.

Throws:

java.io.IOException - if it is not possible to reconfigure the interface.

java.lang.IllegalArgumentException - if netif or conf is null.

disable

public static void disable(java.net.NetworkInterface netif)
                    throws java.lang.IllegalStateException,
                           java.io.IOException

Disables a network interface (software side). A disabled network interface is no longer available for communications. Current communications may be interrupted, raising IOException.

Parameters:

netif - the network interface to disable.

Throws:

java.lang.IllegalStateException - if the network interface is currently stopped.

java.io.IOException - if an I/O error occurs.

java.lang.IllegalArgumentException - if netif is null.

enable

public static void enable(java.net.NetworkInterface netif)
                   throws java.lang.IllegalStateException,
                          java.io.IOException

Enables a network interface (software side). An enabled network interface is available for communications, assuming that start(NetworkInterface) has been called beforehand.

Parameters:

netif - the network interface to enable.

Throws:

java.lang.IllegalStateException - if the interface is currently stopped.

java.io.IOException - if an I/O error occurs.

java.lang.IllegalArgumentException - if netif is null.

getIPConfiguration

public static IPConfiguration getIPConfiguration(java.net.NetworkInterface netif)
                                          throws java.io.IOException

Gets the current IP configuration of a network interface.

Parameters:

netif - the network interface.

Returns:

the current IP configuration of the network interface.

Throws:

java.io.IOException - if an I/O error occurs.

java.lang.IllegalArgumentException - if netif is null.

isEnabled

public static boolean isEnabled(java.net.NetworkInterface netif)

Tells whether a network interface is enabled or not.

Parameters:

netif - the network interface.

Returns:

true if enabled, false otherwise

Throws:

java.lang.IllegalArgumentException - if netif is null.

isStarted

public static boolean isStarted(java.net.NetworkInterface netif)

Tells whether a network interface is started or not.

Parameters:

netif - the network interface.

Returns:

true if started, false otherwise.

Throws:

java.lang.IllegalArgumentException - if netif is null.

start

public static void start(java.net.NetworkInterface netif)
                  throws java.io.IOException

Starts a network interface (hardware side). Switch on the network interface. The network interface is not enabled, enable(NetworkInterface) has to be called after this method.

Parameters:

netif - the network interface to start.

Throws:

java.io.IOException - if an I/O error occurs.

java.lang.IllegalArgumentException - if netif is null.

stop

public static void stop(java.net.NetworkInterface netif)
                 throws java.io.IOException

Stops a network interface (hardware side). Stopping a network interface will also disable it. Current communications may be interrupted, raising IOExceptions.

Parameters:

netif - the interface to stop.

Throws:

java.io.IOException - if an I/O error occurs.

java.lang.IllegalArgumentException - if netif is null.

setDefault

public static void setDefault(java.net.NetworkInterface netif)
                       throws java.io.IOException

Set a network interface as default. This default network interface will be used for all communications which do not specified a targeted network interface.

Parameters:

netif - the network interface to use as the default one.

Throws:

java.io.IOException - if an I/O error occurs.

java.lang.IllegalArgumentException - if netif is null.