- java.lang.Object
-
- java.net.NetworkInterface
-
public final class NetworkInterface extends Object
This class represents a Network Interface made up of a name, and a list of IP addresses assigned to this interface. It is used to identify the local interface on which a multicast group is joined. Interfaces are normally known by names such as "le0".- Since:
- 1.4
-
-
Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description booleanequals(Object obj)Compares this object against the specified object.static NetworkInterfacegetByIndex(int index)Get a network interface given its index.static NetworkInterfacegetByInetAddress(InetAddress addr)Convenience method to search for a network interface that has the specified Internet Protocol (IP) address bound to it.static NetworkInterfacegetByName(String name)Searches for the network interface with the specified name.StringgetDisplayName()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.intgetIndex()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 theInterfaceAddressesof this network interface.intgetMTU()Returns the Maximum Transmission Unit (MTU) of this interface.StringgetName()Get the name of this network interface.static Enumeration<NetworkInterface>getNetworkInterfaces()Returns anEnumerationof all the interfaces on this machine.NetworkInterfacegetParent()Returns the parent NetworkInterface of this interface if this is a subinterface, ornullif 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.booleanisLoopback()Returns whether a network interface is a loopback interface.booleanisPointToPoint()Returns whether a network interface is a point to point interface.booleanisUp()Returns whether a network interface is up and running.booleanisVirtual()Returns whether this interface is a virtual interface (also called subinterface).static Stream<NetworkInterface>networkInterfaces()Returns aStreamof 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.booleansupportsMulticast()Returns whether a network interface supports multicasting or not.
-
-
-
Method Detail
-
getName
public String getName()
Get the name of this network interface.- Returns:
- the name of this network interface
-
getInetAddresses
public Enumeration<InetAddress> getInetAddresses()
Get an Enumeration with all or a subset of the InetAddresses bound to this network interface.If there is a security manager, its
checkConnectmethod is called for each InetAddress. Only InetAddresses where thecheckConnectdoesn'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()
-
inetAddresses
public Stream<InetAddress> inetAddresses()
Get a Stream of all or a subset of the InetAddresses bound to this network interface.If there is a security manager, its
checkConnectmethod is called for each InetAddress. Only InetAddresses where thecheckConnectdoesn'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
public List<InterfaceAddress> getInterfaceAddresses()
Get a List of all or a subset of theInterfaceAddressesof this network interface.If there is a security manager, its
checkConnectmethod is called with the InetAddress for each InterfaceAddress. Only InterfaceAddresses where thecheckConnectdoesn't throw a SecurityException will be returned in the List.- Returns:
- a
Listobject with all or a subset of the InterfaceAddresss of this network interface - Since:
- 1.6
-
getSubInterfaces
public Enumeration<NetworkInterface> 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()
-
subInterfaces
public Stream<NetworkInterface> 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
public NetworkInterface getParent()
Returns the parent NetworkInterface of this interface if this is a subinterface, ornullif it is a physical (non virtual) interface or has no parent.- Returns:
- The
NetworkInterfacethis interface is attached to. - Since:
- 1.6
-
getIndex
public int getIndex()
Returns the index of this network interface. The index is an integer greater or equal to zero, or-1for 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
-1if the index is unknown - Since:
- 1.7
- See Also:
getByIndex(int)
-
getDisplayName
public String 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.
-
getByName
public static NetworkInterface getByName(String name) throws SocketException
Searches for the network interface with the specified name.- Parameters:
name- The name of the network interface.- Returns:
- A
NetworkInterfacewith the specified name, ornullif there is no network interface with the specified name. - Throws:
SocketException- If an I/O error occurs.NullPointerException- If the specified name isnull.
-
getByIndex
public static NetworkInterface getByIndex(int index) throws SocketException
Get a network interface given its index.- Parameters:
index- an integer, the index of the interface- Returns:
- the NetworkInterface obtained from its index, or
nullif 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()
-
getByInetAddress
public static NetworkInterface getByInetAddress(InetAddress addr) throws SocketException
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- TheInetAddressto search with.- Returns:
- A
NetworkInterfaceornullif there is no network interface with the specified IP address. - Throws:
SocketException- If an I/O error occurs.NullPointerException- If the specified address isnull.
-
getNetworkInterfaces
public static Enumeration<NetworkInterface> getNetworkInterfaces() throws SocketException
Returns anEnumerationof all the interfaces on this machine. TheEnumerationcontains 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()
-
networkInterfaces
public static Stream<NetworkInterface> networkInterfaces() throws SocketException
Returns aStreamof all the interfaces on this machine. TheStreamcontains 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
-
isUp
public boolean isUp() throws SocketExceptionReturns whether a network interface is up and running.- Returns:
trueif the interface is up and running.- Throws:
SocketException- if an I/O error occurs.- Since:
- 1.6
-
isLoopback
public boolean isLoopback() throws SocketExceptionReturns whether a network interface is a loopback interface.- Returns:
trueif the interface is a loopback interface.- Throws:
SocketException- if an I/O error occurs.- Since:
- 1.6
-
isPointToPoint
public boolean isPointToPoint() throws SocketExceptionReturns 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:
trueif the interface is a point to point interface.- Throws:
SocketException- if an I/O error occurs.- Since:
- 1.6
-
supportsMulticast
public boolean supportsMulticast() throws SocketExceptionReturns whether a network interface supports multicasting or not.- Returns:
trueif the interface supports Multicasting.- Throws:
SocketException- if an I/O error occurs.- Since:
- 1.6
-
getHardwareAddress
public byte[] getHardwareAddress() throws SocketExceptionReturns 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
nullif 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
-
getMTU
public int getMTU() throws SocketExceptionReturns 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
-
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:
trueif this interface is a virtual interface.- Since:
- 1.6
-
equals
public boolean equals(Object obj)
Compares this object against the specified object. The result istrueif and only if the argument is notnulland it represents the same NetworkInterface as this object.Two instances of
NetworkInterfacerepresent the same NetworkInterface if both name and addrs are the same for both.- Overrides:
equalsin classObject- Parameters:
obj- the object to compare against.- Returns:
trueif the objects are the same;falseotherwise.- See Also:
InetAddress.getAddress()
-
-