public final class NetworkInterface extends Object
- Since:
- 1.4
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Method Summary
Modifier and Type Method 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()
Get 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 theInterfaceAddresses
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 anEnumeration
of all the interfaces on this machine.NetworkInterface
getParent()
Returns the parent NetworkInterface of this interface if this is a subinterface, ornull
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.Stream<InetAddress>
inetAddresses()
Get a Stream of all or a subset of the InetAddresses bound to this network interface.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).static Stream<NetworkInterface>
networkInterfaces()
Returns aStream
of all the interfaces on this machine.Stream<NetworkInterface>
subInterfaces()
Get a Stream of all subinterfaces (also known as virtual interfaces) attached to this network interface.boolean
supportsMulticast()
Returns whether a network interface supports multicasting or not.
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Method Details
-
getName
Get the name of this network interface.- Returns:
- the name of this network interface
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getInetAddresses
Get an Enumeration with all or a subset of the InetAddresses bound to this network interface.If there is a security manager, its
checkConnect
method is called for each InetAddress. Only InetAddresses where thecheckConnect
doesn't throw a SecurityException will be returned in the Enumeration. However, if the caller has theNetPermission
("getNetworkInformation") permission, then all InetAddresses are returned.- Returns:
- an Enumeration object with all or a subset of the InetAddresses bound to this network interface
- See Also:
inetAddresses()
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inetAddresses
Get a Stream of all or a subset of the InetAddresses bound to this network interface.If there is a security manager, its
checkConnect
method is called for each InetAddress. Only InetAddresses where thecheckConnect
doesn't throw a SecurityException will be returned in the Stream. However, if the caller has theNetPermission
("getNetworkInformation") permission, then all InetAddresses are returned.- Returns:
- a Stream object with all or a subset of the InetAddresses bound to this network interface
- Since:
- 9
-
getInterfaceAddresses
Get a List of all or a subset of theInterfaceAddresses
of this network interface.If there is a security manager, its
checkConnect
method is called with the InetAddress for each InterfaceAddress. Only InterfaceAddresses where thecheckConnect
doesn't throw a SecurityException will be returned in the List.- Returns:
- a
List
object with all or a subset of the InterfaceAddress of this network interface - Since:
- 1.6
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getSubInterfaces
Get an Enumeration with all the subinterfaces (also known as virtual interfaces) attached to this network interface.For instance eth0:1 will be a subinterface to eth0.
- Returns:
- an Enumeration object with all of the subinterfaces of this network interface
- Since:
- 1.6
- See Also:
subInterfaces()
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subInterfaces
Get a Stream of all subinterfaces (also known as virtual interfaces) attached to this network interface.- Returns:
- a Stream object with all of the subinterfaces of this network interface
- Since:
- 9
-
getParent
Returns the parent NetworkInterface of this interface if this is a subinterface, ornull
if it is a physical (non virtual) interface or has no parent.- Returns:
- The
NetworkInterface
this interface is attached to. - Since:
- 1.6
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getIndex
public int getIndex()Returns the index of this network interface. The index is an integer greater or equal to zero, or-1
for unknown. This is a system specific value and interfaces with the same name can have different indexes on different machines.- Returns:
- the index of this network interface or
-1
if the index is unknown - Since:
- 1.7
- See Also:
getByIndex(int)
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getDisplayName
Get the display name of this network interface. A display name is a human readable String describing the network device.- Returns:
- a non-empty string representing the display name of this network interface, or null if no display name is available.
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getByName
Searches for the network interface with the specified name.- Parameters:
name
- The name of the network interface.- Returns:
- A
NetworkInterface
with the specified name, ornull
if there is no network interface with the specified name. - Throws:
SocketException
- If an I/O error occurs.NullPointerException
- If the specified name isnull
.
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getByIndex
Get a network interface given its index.- Parameters:
index
- an integer, the index of the interface- Returns:
- the NetworkInterface obtained from its index, or
null
if there is no interface with such an index on the system - Throws:
SocketException
- if an I/O error occurs.IllegalArgumentException
- if index has a negative value- Since:
- 1.7
- See Also:
getIndex()
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getByInetAddress
Convenience method to search for a network interface that has the specified Internet Protocol (IP) address bound to it.If the specified IP address is bound to multiple network interfaces it is not defined which network interface is returned.
- Parameters:
addr
- TheInetAddress
to search with.- Returns:
- A
NetworkInterface
ornull
if there is no network interface with the specified IP address. - Throws:
SocketException
- If an I/O error occurs.NullPointerException
- If the specified address isnull
.
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getNetworkInterfaces
Returns anEnumeration
of all the interfaces on this machine. TheEnumeration
contains at least one element, possibly representing a loopback interface that only supports communication between entities on this machine.- API Note:
- this method can be used in combination with
getInetAddresses()
to obtain all IP addresses for this node - Returns:
- an Enumeration of NetworkInterfaces found on this machine
- Throws:
SocketException
- if an I/O error occurs, or if the platform does not have at least one configured network interface.- See Also:
networkInterfaces()
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networkInterfaces
Returns aStream
of all the interfaces on this machine. TheStream
contains at least one interface, possibly representing a loopback interface that only supports communication between entities on this machine.- API Note:
- this method can be used in combination with
inetAddresses()
} to obtain a stream of all IP addresses for this node, for example:Stream<InetAddress> addrs = NetworkInterface.networkInterfaces() .flatMap(NetworkInterface::inetAddresses);
- Returns:
- a Stream of NetworkInterfaces found on this machine
- Throws:
SocketException
- if an I/O error occurs, or if the platform does not have at least one configured network interface.- Since:
- 9
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isUp
Returns whether a network interface is up and running.- Returns:
true
if the interface is up and running.- Throws:
SocketException
- if an I/O error occurs.- Since:
- 1.6
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isLoopback
Returns whether a network interface is a loopback interface.- Returns:
true
if the interface is a loopback interface.- Throws:
SocketException
- if an I/O error occurs.- Since:
- 1.6
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isPointToPoint
Returns whether a network interface is a point to point interface. A typical point to point interface would be a PPP connection through a modem.- Returns:
true
if the interface is a point to point interface.- Throws:
SocketException
- if an I/O error occurs.- Since:
- 1.6
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supportsMulticast
Returns whether a network interface supports multicasting or not.- Returns:
true
if the interface supports Multicasting.- Throws:
SocketException
- if an I/O error occurs.- Since:
- 1.6
-
getHardwareAddress
Returns the hardware address (usually MAC) of the interface if it has one and if it can be accessed given the current privileges. If a security manager is set, then the caller must have the permissionNetPermission
("getNetworkInformation").- Returns:
- a byte array containing the address, or
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") - Throws:
SocketException
- if an I/O error occurs.- Since:
- 1.6
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getMTU
Returns the Maximum Transmission Unit (MTU) of this interface.- Returns:
- the value of the MTU for that interface.
- Throws:
SocketException
- if an I/O error occurs.- Since:
- 1.6
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isVirtual
public boolean isVirtual()Returns whether this interface is a virtual interface (also called subinterface). Virtual interfaces are, on some systems, interfaces created as a child of a physical interface and given different settings (like address or MTU). Usually the name of the interface will the name of the parent followed by a colon (:) and a number identifying the child since there can be several virtual interfaces attached to a single physical interface.- Returns:
true
if this interface is a virtual interface.- Since:
- 1.6
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equals
Compares this object against the specified object. The result istrue
if and only if the argument is notnull
and it represents the same NetworkInterface as this object.Two instances of
NetworkInterface
represent the same NetworkInterface if both the name and the set ofInetAddress
es bound to the interfaces are equal.- Overrides:
equals
in classObject
- API Note:
- two
NetworkInterface
objects referring to the same underlying interface may not compare equal if the addresses of the underlying interface are being dynamically updated by the system. - Parameters:
obj
- the object to compare against.- Returns:
true
if the objects are the same;false
otherwise.- See Also:
InetAddress.getAddress()
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