public final class NetworkInterface extends Object
Modifier and Type | Method and Description |
---|---|
boolean |
equals(Object obj)
Compares this object against the specified object.
|
static NetworkInterface |
getByIndex(int index)
Get a network interface given its index.
|
static NetworkInterface |
getByInetAddress(InetAddress addr)
Convenience method to search for a network interface that
has the specified Internet Protocol (IP) address bound to
it.
|
static NetworkInterface |
getByName(String name)
Searches for the network interface with the specified name.
|
String |
getDisplayName()
Get the display name of this network interface.
|
byte[] |
getHardwareAddress()
Returns the hardware address (usually MAC) of the interface if it
has one and if it can be accessed given the current privileges.
|
int |
getIndex()
Returns the index of this network interface.
|
Enumeration<InetAddress> |
getInetAddresses()
Convenience method to return an Enumeration with all or a
subset of the InetAddresses bound to this network interface.
|
List<InterfaceAddress> |
getInterfaceAddresses()
Get a List of all or a subset of the
InterfaceAddresses
of this network interface. |
int |
getMTU()
Returns the Maximum Transmission Unit (MTU) of this interface.
|
String |
getName()
Get the name of this network interface.
|
static Enumeration<NetworkInterface> |
getNetworkInterfaces()
Returns all the interfaces on this machine.
|
NetworkInterface |
getParent()
Returns the parent NetworkInterface of this interface if this is
a subinterface, or
null if it is a physical
(non virtual) interface or has no parent. |
Enumeration<NetworkInterface> |
getSubInterfaces()
Get an Enumeration with all the subinterfaces (also known as virtual
interfaces) attached to this network interface.
|
int |
hashCode()
Returns a hash code value for the object.
|
boolean |
isLoopback()
Returns whether a network interface is a loopback interface.
|
boolean |
isPointToPoint()
Returns whether a network interface is a point to point interface.
|
boolean |
isUp()
Returns whether a network interface is up and running.
|
boolean |
isVirtual()
Returns whether this interface is a virtual interface (also called
subinterface).
|
boolean |
supportsMulticast()
Returns whether a network interface supports multicasting or not.
|
String |
toString()
Returns a string representation of the object.
|
public String getName()
public Enumeration<InetAddress> getInetAddresses()
If there is a security manager, its checkConnect
method is called for each InetAddress. Only InetAddresses where
the checkConnect
doesn't throw a SecurityException
will be returned in the Enumeration. However, if the caller has the
NetPermission
("getNetworkInformation") permission, then all
InetAddresses are returned.
public List<InterfaceAddress> getInterfaceAddresses()
InterfaceAddresses
of this network interface.
If there is a security manager, its checkConnect
method is called with the InetAddress for each InterfaceAddress.
Only InterfaceAddresses where the checkConnect
doesn't throw
a SecurityException will be returned in the List.
List
object with all or a subset of the
InterfaceAddresss of this network interfacepublic Enumeration<NetworkInterface> getSubInterfaces()
For instance eth0:1 will be a subinterface to eth0.
public NetworkInterface getParent()
null
if it is a physical
(non virtual) interface or has no parent.NetworkInterface
this interface is attached to.public int getIndex()
-1
for unknown. This is a system specific value
and interfaces with the same name can have different indexes on different
machines.-1
if the index is
unknowngetByIndex(int)
public String getDisplayName()
public static NetworkInterface getByName(String name) throws SocketException
name
- The name of the network interface.NetworkInterface
with the specified name,
or null
if there is no network interface
with the specified name.SocketException
- If an I/O error occurs.NullPointerException
- If the specified name is null
.public static NetworkInterface getByIndex(int index) throws SocketException
index
- an integer, the index of the interfacenull
if
there is no interface with such an index on the systemSocketException
- if an I/O error occurs.IllegalArgumentException
- if index has a negative valuegetIndex()
public static NetworkInterface getByInetAddress(InetAddress addr) throws SocketException
If the specified IP address is bound to multiple network interfaces it is not defined which network interface is returned.
addr
- The InetAddress
to search with.NetworkInterface
or null
if there is no network interface
with the specified IP address.SocketException
- If an I/O error occurs.NullPointerException
- If the specified address is null
.public static Enumeration<NetworkInterface> getNetworkInterfaces() throws SocketException
Enumeration
contains at least one element, possibly representing a loopback
interface that only supports communication between entities on
this machine.
NOTE: can use getNetworkInterfaces()+getInetAddresses()
to obtain all IP addresses for this nodeSocketException
- if an I/O error occurs.public boolean isUp() throws SocketException
true
if the interface is up and running.SocketException
- if an I/O error occurs.public boolean isLoopback() throws SocketException
true
if the interface is a loopback interface.SocketException
- if an I/O error occurs.public boolean isPointToPoint() throws SocketException
true
if the interface is a point to point
interface.SocketException
- if an I/O error occurs.public boolean supportsMulticast() throws SocketException
true
if the interface supports Multicasting.SocketException
- if an I/O error occurs.public byte[] getHardwareAddress() throws SocketException
NetPermission
("getNetworkInformation").null
if
the address doesn't exist, is not accessible or a security
manager is set and the caller does not have the permission
NetPermission("getNetworkInformation")SocketException
- if an I/O error occurs.public int getMTU() throws SocketException
SocketException
- if an I/O error occurs.public boolean isVirtual()
true
if this interface is a virtual interface.public boolean equals(Object obj)
true
if and only if the argument is
not null
and it represents the same NetworkInterface
as this object.
Two instances of NetworkInterface
represent the same
NetworkInterface if both name and addrs are the same for both.
equals
in class Object
obj
- the object to compare against.true
if the objects are the same;
false
otherwise.InetAddress.getAddress()
public int hashCode()
Object
HashMap
.
The general contract of hashCode
is:
hashCode
method
must consistently return the same integer, provided no information
used in equals
comparisons on the object is modified.
This integer need not remain consistent from one execution of an
application to another execution of the same application.
equals(Object)
method, then calling the hashCode
method on each of
the two objects must produce the same integer result.
Object.equals(java.lang.Object)
method, then calling the hashCode
method on each of the
two objects must produce distinct integer results. However, the
programmer should be aware that producing distinct integer results
for unequal objects may improve the performance of hash tables.
As much as is reasonably practical, the hashCode method defined by
class Object
does return distinct integers for distinct
objects. (This is typically implemented by converting the internal
address of the object into an integer, but this implementation
technique is not required by the
Java™ programming language.)
hashCode
in class Object
Object.equals(java.lang.Object)
,
System.identityHashCode(java.lang.Object)
public String toString()
Object
toString
method returns a string that
"textually represents" this object. The result should
be a concise but informative representation that is easy for a
person to read.
It is recommended that all subclasses override this method.
The toString
method for class Object
returns a string consisting of the name of the class of which the
object is an instance, the at-sign character `@
', and
the unsigned hexadecimal representation of the hash code of the
object. In other words, this method returns a string equal to the
value of:
getClass().getName() + '@' + Integer.toHexString(hashCode())
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