NetworkInterface

equals

public boolean equals (Object obj)

Compares this object against the specified object. The result is 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.

getByIndex

public static NetworkInterface getByIndex (int index)

Get a network interface given its index.

getByInetAddress

public static NetworkInterface getByInetAddress (InetAddress addr)

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.

getByName

public static NetworkInterface getByName (String name)

Searches for the network interface with the specified name.

getDisplayName

public String getDisplayName ()

Get the display name of this network interface. A display name is a human readable String describing the network device.

getHardwareAddress

public 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. If a security manager is set, then the caller must have the permission NetPermission("getNetworkInformation").

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.

getInetAddresses

public Enumeration<InetAddress> getInetAddresses ()

Convenience method to return 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 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.

getInterfaceAddresses

public List<InterfaceAddress> getInterfaceAddresses ()

Get a List of all or a subset of the 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.

getMTU

public int getMTU ()

Returns the Maximum Transmission Unit (MTU) of this interface.

getName

public String getName ()

Get the name of this network interface.

getNetworkInterfaces

public static Enumeration<NetworkInterface> getNetworkInterfaces ()

Returns all the interfaces on this machine. The 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 node

For non-system apps, this method will only return information for NetworkInterfaces associated with an InetAddress.

ANDROID NOTE: On Android versions before S (API level 31), this method may throw a NullPointerException if called in an environment where there is a virtual interface without a parent interface present.

getParent

public 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.

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.

hashCode

public int hashCode ()

Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by HashMap.

The general contract of hashCode is:

• Whenever it is invoked on the same object more than once during an execution of a Java application, the 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.
• If two objects are equal according to the equals method, then calling the hashCode method on each of the two objects must produce the same integer result.
• It is not required that if two objects are unequal according to the equals 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.

isLoopback

public boolean isLoopback ()

Returns whether a network interface is a loopback interface.

isPointToPoint

public boolean 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.

isUp

public boolean isUp ()

Returns whether a network interface is up and running.

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.

supportsMulticast

public boolean supportsMulticast ()

Returns whether a network interface supports multicasting or not.

toString

public String toString ()

Returns a string representation of the object.