java.lang.Object
- org.drasyl.util.NetworkUtil

public final class NetworkUtil
extends Object

Utility class for network-related operations.

Field Summary

Fields
Modifier and Type	Field	Description
`static Duration`	`EXTERNAL_IP_ADDRESS_TIMEOUT`
`static Duration`	`LOCAL_ADDRESS_FOR_REMOTE_TIMEOUT`
`static int`	`MAX_PORT_NUMBER`	The maximum server port number.
`static int`	`MIN_PORT_NUMBER`	The minimum server port number.

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static boolean`	`alive(String host, int port)`	Checks to see if a specific host:port is available.
`static boolean`	`available(int port)`	Checks to see if a specific port is available.
`static byte[]`	`cidr2Netmask(short cidr, int byteLength)`	Converts a given CIDR mask to valid IPv4 or IPv6 network mask.
`static InetAddress`	`createInetAddress(String str)`	Creates a `InetAddress` by parsing the given string.
`static Set<InetAddress>`	`getAddresses()`	Returns a list of the IP addresses of all network interfaces of the local computer.
`static InetAddress`	`getDefaultGateway()`
`static Inet4Address`	`getExternalIPv4Address()`	Determines the external IPv4 address.
`static Inet6Address`	`getExternalIPv6Address()`	Determines the external IPv6 address.
`static byte[]`	`getIpv4MappedIPv6AddressBytes(InetAddress address)`
`static InetAddress`	`getLocalAddressForRemoteAddress(InetSocketAddress remoteAddress)`	Establishes a connection to `remoteAddress` and returns the local address used for it.If an error occurs, `null` is returned.
`static String`	`getLocalHostName()`	Returns the local host name.
`static short`	`getNetworkPrefixLength(InetAddress address)`	Returns the network prefix length for given address.
`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.
`static boolean`	`isValidPort(int port)`	Checks if a port is valid or not.
`static boolean`	`sameNetwork(byte[] x, byte[] y, short cidr)`	Checks if two given addresses are in the same network.
`static boolean`	`sameNetwork(InetAddress a, InetAddress b, short mask)`	Checks if two given addresses are in the same network.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - MIN_PORT_NUMBER
```
public static final int MIN_PORT_NUMBER
```
    The minimum server port number.
    
    See Also:
    
    Constant Field Values
  - MAX_PORT_NUMBER
```
public static final int MAX_PORT_NUMBER
```
    The maximum server port number.
    
    See Also:
    
    Constant Field Values
  - LOCAL_ADDRESS_FOR_REMOTE_TIMEOUT
```
public static final Duration LOCAL_ADDRESS_FOR_REMOTE_TIMEOUT
```
  - EXTERNAL_IP_ADDRESS_TIMEOUT
```
public static final Duration EXTERNAL_IP_ADDRESS_TIMEOUT
```
- Method Detail
  - getExternalIPv4Address
```
public static Inet4Address getExternalIPv4Address()
```
    Determines the external IPv4 address.
    Note: This is a blocking method, because it connects to external server that may react slowly or not at all.
    
    Returns:
    
    the external IPv4 address or null in case of error
  - getExternalIPv6Address
```
public static Inet6Address getExternalIPv6Address()
```
    Determines the external IPv6 address.
    Note: This is a blocking method, because it connects to external server that may react slowly or not at all.
    
    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
  - getDefaultGateway
```
public static InetAddress getDefaultGateway()
```
  - getIpv4MappedIPv6AddressBytes
```
public static byte[] getIpv4MappedIPv6AddressBytes(InetAddress address)
```
  - getLocalAddressForRemoteAddress
```
public static InetAddress getLocalAddressForRemoteAddress(InetSocketAddress remoteAddress)
```
    Establishes a connection to remoteAddress and returns the local address used for it.If an error occurs, null is returned.
    
    Parameters:
    
    remoteAddress - The remote address
    
    Returns:
    
    local address used to connect to remoteAddress, or null in case of error

Class NetworkUtil

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

MIN_PORT_NUMBER

MAX_PORT_NUMBER

LOCAL_ADDRESS_FOR_REMOTE_TIMEOUT

EXTERNAL_IP_ADDRESS_TIMEOUT

Method Detail

getExternalIPv4Address

getExternalIPv6Address

available

isValidPort

alive

getAddresses

isValidNonSpecialIPAddress

getLocalHostName

createInetAddress

getNetworkPrefixLength

sameNetwork

sameNetwork

cidr2Netmask

getDefaultGateway

getIpv4MappedIPv6AddressBytes

getLocalAddressForRemoteAddress