Package org.drasyl.util

Class NetworkUtil

java.lang.Object
org.drasyl.util.NetworkUtil
public final class NetworkUtil extends Object
Utility class for network-related operations.

  • Field Details

    • MIN_PORT_NUMBER

      public static final int MIN_PORT_NUMBER
      The minimum server port number.
      See Also:

    • MAX_PORT_NUMBER

      public static final int MAX_PORT_NUMBER
      The maximum server port number.
      See Also:

  • Method Details

    • getExternalIPv4Address

      public static Inet4Address getExternalIPv4Address()
      Determines the external IPv4 address.
      Returns:
      the external IPv4 address or null in case of error

    • getExternalIPv6Address

      public static Inet6Address getExternalIPv6Address()
      Determines the external IPv6 address.
      Returns:
      the external IPv6 address or null in case of error

    • available

      public static boolean available(int port)
      Checks to see if a specific port is available.

      Source: Apache camel

      Parameters:
      port - the port number to check for availability
      Returns:
      true if the port is available, or false if not
      Throws:
      IllegalArgumentException - is thrown if the port number is out of range

    • isValidPort

      public static boolean isValidPort(int port)
      Checks if a port is valid or not.
      Parameters:
      port - port that should be validated.
      Returns:
      true if valid, otherwise false

    • alive

      public static boolean alive(String host, int port)
      Checks to see if a specific host:port is available.
      Parameters:
      host - host name or IP address to check for availability
      port - the port number to check for availability
      Returns:
      true if the host:port is available, or false if not
      Throws:
      IllegalArgumentException - is thrown if the port number is out of range

    • getAddresses

      public static Set<InetAddress> getAddresses()
      Returns a list of the IP addresses of all network interfaces of the local computer. If no IP addresses can be obtained, the loopback address is returned.
      Returns:
      list of IP addresses of all network interfaces of local computer or loopback address if no address can be obtained

    • isValidNonSpecialIPAddress

      public static boolean isValidNonSpecialIPAddress(InetAddress address)
      Check if the given address is a normal IP address that is neither a loopback, link local nor multicast address.
      Parameters:
      address - the address that should be checked
      Returns:
      true if the address is a normal IP address, false otherwise

    • getLocalHostName

      public static String getLocalHostName()
      Returns the local host name. If no host name can be determined, null is returned.
      Returns:
      the local host name. If no host name can be determined, null is returned.

    • createInetAddress

      public static InetAddress createInetAddress(String str)
      Creates a InetAddress by parsing the given string.

      This convenience factory method works as if by invoking the InetAddress.getByName(java.lang.String) constructor; any UnknownHostException thrown by the constructor is caught and wrapped in a new IllegalArgumentException object, which is then thrown.

      This method is provided for use in situations where it is known that the given string is a legal InetAddress, for example for InetAddress constants declared within a program, and so it would be considered a programming error for the string not to parse as such. The constructors, which throw UnknownHostException directly, should be used in situations where a InetAddress is being constructed from user input or from some other source that may be prone to errors.

      Parameters:
      str - The string to be parsed into a InetAddress
      Returns:
      The new InetAddress
      Throws:
      IllegalArgumentException - if no IP address for the str could be found, or if a scope_id was specified for a global IPv6 address.

    • getNetworkPrefixLength

      public static short getNetworkPrefixLength(InetAddress address)
      Returns the network prefix length for given address. This is also known as the subnet mask in the context of IPv4 addresses. Typical IPv4 values would be 8 (255.0.0.0), 16 (255.255.0.0) or 24 (255.255.255.0).

      Typical IPv6 values would be 128 (::1/128) or 10 (fe80::203:baff:fe27:1243/10)

      Parameters:
      address - The InetAddress to search with.
      Returns:
      a short representing the prefix length for the subnet of that address or -1 if there is no network interface with given IP address.
      Throws:
      NullPointerException - If the specified address is null.

    • sameNetwork

      public static boolean sameNetwork(InetAddress a, InetAddress b, short mask)
      Checks if two given addresses are in the same network.
      Parameters:
      a - first address
      b - second address
      mask - the network mask in CIDR notation
      Returns:
      true if the two given addresses are in the same network, false otherwise

    • sameNetwork

      public static boolean sameNetwork(byte[] x, byte[] y, short cidr)
      Checks if two given addresses are in the same network.
      Parameters:
      x - first address
      y - second address
      cidr - the network mask in CIDR notation
      Returns:
      true if the two given addresses are in the same network, false otherwise

    • cidr2Netmask

      public static byte[] cidr2Netmask(short cidr, int byteLength)
      Converts a given CIDR mask to valid IPv4 or IPv6 network mask.
      Parameters:
      cidr - the cidr
      byteLength - the final mask length (IPv4 = 4 bytes, IPv6 = 16 bytes)
      Returns:
      the CIDR as network mask byte array
      Throws:
      IllegalArgumentException - if the byteLength argument is invalid