org.apache.flink.util

Class NetUtils

java.lang.Object

org.apache.flink.util.NetUtils

@Internal
public class NetUtils
extends Object

Utility for various network related tasks (such as finding free ports).

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	NetUtils.SocketFactory A factory for a local socket from port number.

Constructor Summary

Constructors

Constructor and Description
NetUtils()

Method Summary

Modifier and Type	Method and Description
static Socket	acceptWithoutTimeout(ServerSocket serverSocket) Calls ServerSocket.accept() on the provided server socket, suppressing any thrown SocketTimeoutExceptions.
static ServerSocket	createSocketFromPorts(Iterator<Integer> portsIterator, NetUtils.SocketFactory factory) Tries to allocate a socket from the given sets of ports.
static int	getAvailablePort() Find a non-occupied port.
static URL	getCorrectHostnamePort(String hostPort) Converts a string of the form "host:port" into an URL.
static String	getHostnameFromFQDN(String fqdn) Turn a fully qualified domain name (fqdn) into a hostname.
static Iterator<Integer>	getPortRangeFromString(String rangeDefinition) Returns an iterator over available ports defined by the range definition.
static String	getWildcardIPAddress() Returns the wildcard address to listen on all interfaces.
static String	hostAndPortToUrlString(String host, int port) Normalizes and encodes a hostname and port to be included in URL.
static String	ipAddressAndPortToUrlString(InetAddress address, int port) Encodes an IP address and port to be included in URL.
static String	ipAddressToUrlString(InetAddress address) Encodes an IP address properly as a URL string.
static boolean	isValidClientPort(int port) Check whether the given port is in right range when connecting to somewhere.
static boolean	isValidHostPort(int port) check whether the given port is in right range when getting port from local system.
static InetSocketAddress	parseHostPortAddress(String hostPort) Converts a string of the form "host:port" into an InetSocketAddress.
static String	socketAddressToUrlString(InetSocketAddress address) Encodes an IP address and port to be included in URL.
static String	unresolvedHostAndPortToNormalizedString(String host, int port) Returns a valid address for Akka.
static String	unresolvedHostToNormalizedString(String host) Returns an address in a normalized format for Akka.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

NetUtils

public NetUtils()

Method Detail

getHostnameFromFQDN

public static String getHostnameFromFQDN(String fqdn)

Turn a fully qualified domain name (fqdn) into a hostname. If the fqdn has multiple subparts (separated by a period '.'), it will take the first part. Otherwise it takes the entire fqdn.

Parameters:

fqdn - The fully qualified domain name.

Returns:

The hostname.

getCorrectHostnamePort

public static URL getCorrectHostnamePort(String hostPort)

Converts a string of the form "host:port" into an URL.

Parameters:

hostPort - The "host:port" string.

Returns:

The converted URL.

parseHostPortAddress

public static InetSocketAddress parseHostPortAddress(String hostPort)

Converts a string of the form "host:port" into an InetSocketAddress.

Parameters:

hostPort - The "host:port" string.

Returns:

The converted InetSocketAddress.

acceptWithoutTimeout

public static Socket acceptWithoutTimeout(ServerSocket serverSocket)
                                   throws IOException

Calls ServerSocket.accept() on the provided server socket, suppressing any thrown SocketTimeoutExceptions. This is a workaround for the underlying JDK-8237858 bug in JDK 11 that can cause errant SocketTimeoutExceptions to be thrown at unexpected times.

This method expects the provided ServerSocket has no timeout set (SO_TIMEOUT of 0), indicating an infinite timeout. It will suppress all SocketTimeoutExceptions, even if a ServerSocket with a non-zero timeout is passed in.

Parameters:

serverSocket - a ServerSocket with SO_TIMEOUT set to 0; if SO_TIMEOUT is greater than 0, then this method will suppress SocketTimeoutException; must not be null; SO_TIMEOUT option must be set to 0

Returns:

the new Socket

Throws:

IOException - see ServerSocket.accept()

See Also:

JDK-8237858

getAvailablePort

public static int getAvailablePort()

Find a non-occupied port.

Returns:

A non-occupied port.

unresolvedHostToNormalizedString

public static String unresolvedHostToNormalizedString(String host)

Returns an address in a normalized format for Akka. When an IPv6 address is specified, it normalizes the IPv6 address to avoid complications with the exact URL match policy of Akka.

Parameters:

host - The hostname, IPv4 or IPv6 address

Returns:

host which will be normalized if it is an IPv6 address

unresolvedHostAndPortToNormalizedString

public static String unresolvedHostAndPortToNormalizedString(String host,
                                                             int port)

Returns a valid address for Akka. It returns a String of format 'host:port'. When an IPv6 address is specified, it normalizes the IPv6 address to avoid complications with the exact URL match policy of Akka.

Parameters:

host - The hostname, IPv4 or IPv6 address

port - The port

Returns:

host:port where host will be normalized if it is an IPv6 address

ipAddressToUrlString

public static String ipAddressToUrlString(InetAddress address)

Encodes an IP address properly as a URL string. This method makes sure that IPv6 addresses have the proper formatting to be included in URLs.

Parameters:

address - The IP address to encode.

Returns:

The proper URL string encoded IP address.

ipAddressAndPortToUrlString

public static String ipAddressAndPortToUrlString(InetAddress address,
                                                 int port)

Encodes an IP address and port to be included in URL. in particular, this method makes sure that IPv6 addresses have the proper formatting to be included in URLs.

Parameters:

address - The address to be included in the URL.

port - The port for the URL address.

Returns:

The proper URL string encoded IP address and port.

socketAddressToUrlString

public static String socketAddressToUrlString(InetSocketAddress address)

Encodes an IP address and port to be included in URL. in particular, this method makes sure that IPv6 addresses have the proper formatting to be included in URLs.

Parameters:

address - The socket address with the IP address and port.

Returns:

The proper URL string encoded IP address and port.

hostAndPortToUrlString

public static String hostAndPortToUrlString(String host,
                                            int port)
                                     throws UnknownHostException

Normalizes and encodes a hostname and port to be included in URL. In particular, this method makes sure that IPv6 address literals have the proper formatting to be included in URLs.

Parameters:

host - The address to be included in the URL.

port - The port for the URL address.

Returns:

The proper URL string encoded IP address and port.

Throws:

UnknownHostException - Thrown, if the hostname cannot be translated into a URL.

getPortRangeFromString

public static Iterator<Integer> getPortRangeFromString(String rangeDefinition)
                                                throws NumberFormatException

Returns an iterator over available ports defined by the range definition.

Parameters:

rangeDefinition - String describing a single port, a range of ports or multiple ranges.

Returns:

Set of ports from the range definition

Throws:

NumberFormatException - If an invalid string is passed.

createSocketFromPorts

public static ServerSocket createSocketFromPorts(Iterator<Integer> portsIterator,
                                                 NetUtils.SocketFactory factory)

Tries to allocate a socket from the given sets of ports.

Parameters:

portsIterator - A set of ports to choose from.

factory - A factory for creating the SocketServer

Returns:

null if no port was available or an allocated socket.

getWildcardIPAddress

public static String getWildcardIPAddress()

Returns the wildcard address to listen on all interfaces.

Returns:

Either 0.0.0.0 or :: depending on the IP setup.

isValidClientPort

public static boolean isValidClientPort(int port)

Check whether the given port is in right range when connecting to somewhere.

Parameters:

port - the port to check

Returns:

true if the number in the range 1 to 65535

isValidHostPort

public static boolean isValidHostPort(int port)

check whether the given port is in right range when getting port from local system.

Parameters:

port - the port to check

Returns:

true if the number in the range 0 to 65535