public InetSocketAddress(int port) 
{
        this(InetAddress.anyLocalAddress(), 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 - if the port parameter is outside the specified range of valid port values.

 public InetSocketAddress(InetAddress addr,
    int port) 
{
        if (port <  0 || port  > 0xFFFF) {
            throw new IllegalArgumentException("port out of range:" + port);
        }
        this.port = port;
        if (addr == null)
            this.addr = InetAddress.anyLocalAddress();
        else
            this.addr = addr;
}

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 - if the port parameter is outside the specified range of valid port values.

 public InetSocketAddress(String hostname,
    int port) 
{
        if (port <  0 || port  > 0xFFFF) {
            throw new IllegalArgumentException("port out of range:" + port);
        }
        if (hostname == null) {
            throw new IllegalArgumentException("hostname can't be null");
        }
        try {
            addr = InetAddress.getByName(hostname);
        } catch(UnknownHostException e) {
            this.hostname = hostname;
            addr = null;
        }
        this.port = 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 permissiom 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 - if the port parameter is outside the range of valid port values, or if the hostname parameter is null.

SecurityException - if a security manager is present and permission to resolve the host name is denied.

Also see:

isUnresolved()

 public static InetSocketAddress createUnresolved(String host,
    int port) 
{
        if (port <  0 || port  > 0xFFFF) {
            throw new IllegalArgumentException("port out of range:" + port);
        }
        if (host == null) {
            throw new IllegalArgumentException("hostname can't be null");
        }
        InetSocketAddress s = new InetSocketAddress();
        s.port = port;
        s.hostname = host;
        s.addr = null;
        return s;
}

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.

 public final boolean equals(Object obj) 
{
        if (obj == null || !(obj instanceof InetSocketAddress))
            return false;
        InetSocketAddress sockAddr = (InetSocketAddress) obj;
        boolean sameIP = false;
        if (this.addr != null)
            sameIP = this.addr.equals(sockAddr.addr);
        else if (this.hostname != null)
            sameIP = (sockAddr.addr == null) &&
                this.hostname.equalsIgnoreCase(sockAddr.hostname);
        else
            sameIP = (sockAddr.addr == null) && (sockAddr.hostname == null);
        return sameIP && (this.port == sockAddr.port);
}

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 & the port number are compared. Note: Hostnames are case insensitive. e.g. "FooBar" and "foobar" are considered equal.

 public final InetAddress getAddress() 
{
        return addr;
}

Gets the InetAddress.

 public final String getHostName() 
{
        if (hostname != null)
            return hostname;
        if (addr != null)
            return addr.getHostName();
        return null;
}

Gets the hostname. Note: This method may trigger a name service reverse lookup if the address was created with a literal IP address.

 public final String getHostString() 
{
        if (hostname != null)
            return hostname;
        if (addr != null) {
            if (addr.hostName != null)
                return addr.hostName;
            else
                return addr.getHostAddress();
        }
        return null;
}

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 attemptimg a reverse lookup.

 public final int getPort() 
{
        return port;
}

Gets the port number.

 public final int hashCode() 
{
        if (addr != null)
            return addr.hashCode() + port;
        if (hostname != null)
            return hostname.toLowerCase().hashCode() + port;
        return port;
}

Returns a hashcode for this socket address.

 public final boolean isUnresolved() 
{
        return addr == null;
}

Checks whether the address has been resolved or not.

 public String toString() 
{
        if (isUnresolved()) {
            return hostname + ":" + port;
        } else {
            return addr.toString() + ":" + port;
        }
}

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.