InetSocketAddress (Java Platform SE 8 ) (original) (raw)

• java.lang.Object

• • java.net.SocketAddress
  • • java.net.InetSocketAddress

• All Implemented Interfaces:
  Serializable

public class InetSocketAddress
extends SocketAddress
This class implements an IP Socket Address (IP address + port number) It can also be a pair (hostname + port number), in which case an attempt will be made to resolve the hostname. If resolution fails then the address is said to be unresolved but can still be used on some circumstances like connecting through a proxy.
It provides an immutable object used by sockets for binding, connecting, or as returned values.
The wildcard is a special local IP address. It usually means "any" and can only be used for bind operations.
Since:
1.4
See Also:
Socket, ServerSocket, Serialized Form

• • Constructor Summary

  Constructors

  Constructor	Description
  InetSocketAddress(InetAddress addr, int port)	Creates a socket address from an IP address and a port number.
  InetSocketAddress(int port)	Creates a socket address where the IP address is the wildcard address and the port number a specified value.
  InetSocketAddress(String hostname, int port)	Creates a socket address from a hostname and a port number.

  • Method Summary

  All Methods Static Methods Instance Methods Concrete Methods

  Modifier and Type	Method	Description
  static InetSocketAddress	createUnresolved(String host, int port)	Creates an unresolved socket address from a hostname and a port number.
  boolean	equals(Object obj)	Compares this object against the specified object.
  InetAddress	getAddress()	Gets the InetAddress.
  String	getHostName()	Gets the hostname.
  String	getHostString()	Returns the hostname, or the String form of the address if it doesn't have a hostname (it was created using a literal).
  int	getPort()	Gets the port number.
  int	hashCode()	Returns a hashcode for this socket address.
  boolean	isUnresolved()	Checks whether the address has been resolved or not.
  String	toString()	Constructs a string representation of this InetSocketAddress.

     * ### Methods inherited from class java.lang.[Object](../../java/lang/Object.html "class in java.lang")  
     `[clone](../../java/lang/Object.html#clone--), [finalize](../../java/lang/Object.html#finalize--), [getClass](../../java/lang/Object.html#getClass--), [notify](../../java/lang/Object.html#notify--), [notifyAll](../../java/lang/Object.html#notifyAll--), [wait](../../java/lang/Object.html#wait--), [wait](../../java/lang/Object.html#wait-long-), [wait](../../java/lang/Object.html#wait-long-int-)`

• • Constructor Detail

     * #### InetSocketAddress  
     public InetSocketAddress(int port)  
     Creates a socket address where the IP address is the wildcard address and the port number a specified value.  
      A valid port value is between 0 and 65535\. A port number of `zero` will let the system pick up an ephemeral port in a `bind` operation.  
     Parameters:  
     `port` \- The port number  
     Throws:  
     `[IllegalArgumentException](../../java/lang/IllegalArgumentException.html "class in java.lang")` \- if the port parameter is outside the specified range of valid port values.  
     * #### InetSocketAddress  
     public InetSocketAddress([InetAddress](../../java/net/InetAddress.html "class in java.net") addr,  
                              int port)  
     Creates a socket address from an IP address and a port number.  
      A valid port value is between 0 and 65535\. A port number of `zero` will let the system pick up an ephemeral port in a `bind` operation.  
      A `null` address will assign the _wildcard_ address.  
     Parameters:  
     `addr` \- The IP address  
     `port` \- The port number  
     Throws:  
     `[IllegalArgumentException](../../java/lang/IllegalArgumentException.html "class in java.lang")` \- if the port parameter is outside the specified range of valid port values.  
     * #### InetSocketAddress  
     public InetSocketAddress([String](../../java/lang/String.html "class in java.lang") hostname,  
                              int port)  
     Creates a socket address from a hostname and a port number.  
      An attempt will be made to resolve the hostname into an InetAddress. If that attempt fails, the address will be flagged as _unresolved_.  
      If there is a security manager, its `checkConnect` method is called with the host name as its argument to check the permission to resolve it. This could result in a SecurityException.  
      A valid port value is between 0 and 65535\. A port number of `zero` will let the system pick up an ephemeral port in a `bind` operation.  
     Parameters:  
     `hostname` \- the Host name  
     `port` \- The port number  
     Throws:  
     `[IllegalArgumentException](../../java/lang/IllegalArgumentException.html "class in java.lang")` \- if the port parameter is outside the range of valid port values, or if the hostname parameter is null.  
     `[SecurityException](../../java/lang/SecurityException.html "class in java.lang")` \- if a security manager is present and permission to resolve the host name is denied.  
     See Also:  
     [isUnresolved()](../../java/net/InetSocketAddress.html#isUnresolved--)  

  • Method Detail

    * #### createUnresolved  
    public static [InetSocketAddress](../../java/net/InetSocketAddress.html "class in java.net") createUnresolved([String](../../java/lang/String.html "class in java.lang") host,  
                                                     int port)  
    Creates an unresolved socket address from a hostname and a port number.  
     No attempt will be made to resolve the hostname into an InetAddress. The address will be flagged as _unresolved_.  
     A valid port value is between 0 and 65535\. A port number of `zero` will let the system pick up an ephemeral port in a `bind` operation.  
    Parameters:  
    `host` \- the Host name  
    `port` \- The port number  
    Returns:  
    a `InetSocketAddress` representing the unresolved socket address  
    Throws:  
    `[IllegalArgumentException](../../java/lang/IllegalArgumentException.html "class in java.lang")` \- if the port parameter is outside the range of valid port values, or if the hostname parameter is null.  
    Since:  
    1.5  
    See Also:  
    [isUnresolved()](../../java/net/InetSocketAddress.html#isUnresolved--)  
    * #### getPort  
    public final int getPort()  
    Gets the port number.  
    Returns:  
    the port number.  
    * #### getAddress  
    public final [InetAddress](../../java/net/InetAddress.html "class in java.net") getAddress()  
    Gets the `InetAddress`.  
    Returns:  
    the InetAdress or `null` if it is unresolved.  
    * #### getHostName  
    public final [String](../../java/lang/String.html "class in java.lang") getHostName()  
    Gets the `hostname`. Note: This method may trigger a name service reverse lookup if the address was created with a literal IP address.  
    Returns:  
    the hostname part of the address.  
    * #### getHostString  
    public final [String](../../java/lang/String.html "class in java.lang") getHostString()  
    Returns the hostname, or the String form of the address if it doesn't have a hostname (it was created using a literal). This has the benefit of **not** attempting a reverse lookup.  
    Returns:  
    the hostname, or String representation of the address.  
    Since:  
    1.7  
    * #### isUnresolved  
    public final boolean isUnresolved()  
    Checks whether the address has been resolved or not.  
    Returns:  
    `true` if the hostname couldn't be resolved into an `InetAddress`.  
    * #### toString  
    public [String](../../java/lang/String.html "class in java.lang") toString()  
    Constructs a string representation of this InetSocketAddress. This String is constructed by calling toString() on the InetAddress and concatenating the port number (with a colon). If the address is unresolved then the part before the colon will only contain the hostname.  
    Overrides:  
    `[toString](../../java/lang/Object.html#toString--)` in class `[Object](../../java/lang/Object.html "class in java.lang")`  
    Returns:  
    a string representation of this object.  
    * #### equals  
    public final boolean equals([Object](../../java/lang/Object.html "class in java.lang") 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 address as this object.  
     Two instances of `InetSocketAddress` represent the same address if both the InetAddresses (or hostnames if it is unresolved) and port numbers are equal. If both addresses are unresolved, then the hostname and the port number are compared. Note: Hostnames are case insensitive. e.g. "FooBar" and "foobar" are considered equal.  
    Overrides:  
    `[equals](../../java/lang/Object.html#equals-java.lang.Object-)` in class `[Object](../../java/lang/Object.html "class in java.lang")`  
    Parameters:  
    `obj` \- the object to compare against.  
    Returns:  
    `true` if the objects are the same;`false` otherwise.  
    See Also:  
    [InetAddress.equals(java.lang.Object)](../../java/net/InetAddress.html#equals-java.lang.Object-)  
    * #### hashCode  
    public final int hashCode()  
    Returns a hashcode for this socket address.  
    Overrides:  
    `[hashCode](../../java/lang/Object.html#hashCode--)` in class `[Object](../../java/lang/Object.html "class in java.lang")`  
    Returns:  
    a hash code value for this socket address.  
    See Also:  
    [Object.equals(java.lang.Object)](../../java/lang/Object.html#equals-java.lang.Object-), [System.identityHashCode(java.lang.Object)](../../java/lang/System.html#identityHashCode-java.lang.Object-)

Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
Copyright © 1993, 2025, Oracle and/or its affiliates. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.