* 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 {@code bind} operations.
*
* @see java.net.Socket
* @see java.net.ServerSocket
* @since 1.4
*/
public class InetSocketAddress
extends SocketAddress
{
// Private implementation class pointed to by all public methods.
private static class InetSocketAddressHolder {
// The hostname of the Socket Address
private String hostname;
// The IP address of the Socket Address
private InetAddress addr;
// The port number of the Socket Address
private int port;
private InetSocketAddressHolder(String hostname, InetAddress addr, int port) {
this.hostname = hostname;
this.addr = addr;
this.port = port;
}
private int getPort() {
return port;
}
private InetAddress getAddress() {
return addr;
}
private String getHostName() {
if (hostname != null)
return hostname;
if (addr != null)
return addr.getHostName();
return null;
}
private String getHostString() {
if (hostname != null)
return hostname;
if (addr != null) {
if (addr.holder().getHostName() != null)
return addr.holder().getHostName();
else
return addr.getHostAddress();
}
return null;
}
private boolean isUnresolved() {
return addr == null;
}
@Override
public String toString() {
String formatted;
if (isUnresolved()) {
formatted = hostname + "/
* A valid port value is between 0 and 65535.
* A port number of {@code zero} will let the system pick up an
* ephemeral port in a {@code bind} operation.
*
* @param port The port number
* @throws IllegalArgumentException if the port parameter is outside the specified
* range of valid port values.
*/
public InetSocketAddress(int port) {
// Android-changed: Defaults to IPv6.
// this(InetAddress.anyLocalAddress(), port);
this((InetAddress)null, 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 {@code zero} will let the system pick up an
* ephemeral port in a {@code bind} operation.
*
* A {@code null} address will assign the wildcard address.
*
* @param addr The IP address
* @param 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) {
holder = new InetSocketAddressHolder(
null,
// Android-changed: Defaults to IPv6 if addr is null.
// addr == null ? InetAddress.anyLocalAddress() : addr,
addr == null ? Inet6Address.ANY : addr,
checkPort(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 {@code 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 {@code zero} will let the system pick up an
* ephemeral port in a {@code bind} operation.
*
* @param hostname the Host name
* @param port The port number
* @throws IllegalArgumentException if the port parameter is outside the range
* of valid port values, or if the hostname parameter is {@code null}.
* @throws SecurityException if a security manager is present and
* permission to resolve the host name is
* denied.
* @see #isUnresolved()
*/
public InetSocketAddress(String hostname, int port) {
checkHost(hostname);
InetAddress addr = null;
String host = null;
try {
addr = InetAddress.getByName(hostname);
} catch(UnknownHostException e) {
host = hostname;
}
holder = new InetSocketAddressHolder(host, addr, checkPort(port));
}
// private constructor for creating unresolved instances
private InetSocketAddress(int port, String hostname) {
holder = new InetSocketAddressHolder(hostname, null, 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 {@code zero} will let the system pick up an
* ephemeral port in a {@code bind} operation.
*
* @param host the Host name
* @param port The port number
* @throws IllegalArgumentException if the port parameter is outside
* the range of valid port values, or if the hostname
* parameter is {@code null}.
* @see #isUnresolved()
* @return an {@code InetSocketAddress} representing the unresolved
* socket address
* @since 1.5
*/
public static InetSocketAddress createUnresolved(String host, int port) {
return new InetSocketAddress(checkPort(port), checkHost(host));
}
/**
* @serialField hostname String the hostname of the Socket Address
* @serialField addr InetAddress the IP address of the Socket Address
* @serialField port int the port number of the Socket Address
*/
@java.io.Serial
private static final ObjectStreamField[] serialPersistentFields = {
new ObjectStreamField("hostname", String.class),
new ObjectStreamField("addr", InetAddress.class),
new ObjectStreamField("port", int.class)};
/**
* Writes the state of this object to the stream.
*
* @param out the {@code ObjectOutputStream} to which data is written
* @throws IOException if an I/O error occurs
*/
@java.io.Serial
private void writeObject(ObjectOutputStream out)
throws IOException
{
// Don't call defaultWriteObject()
ObjectOutputStream.PutField pfields = out.putFields();
pfields.put("hostname", holder.hostname);
pfields.put("addr", holder.addr);
pfields.put("port", holder.port);
out.writeFields();
}
/**
* Restores the state of this object from the stream.
*
* @param in the {@code ObjectInputStream} from which data is read
* @throws IOException if an I/O error occurs
* @throws ClassNotFoundException if a serialized class cannot be loaded
*/
@java.io.Serial
private void readObject(ObjectInputStream in)
throws IOException, ClassNotFoundException
{
// Don't call defaultReadObject()
ObjectInputStream.GetField oisFields = in.readFields();
final String oisHostname = (String)oisFields.get("hostname", null);
final InetAddress oisAddr = (InetAddress)oisFields.get("addr", null);
final int oisPort = oisFields.get("port", -1);
// Check that our invariants are satisfied
checkPort(oisPort);
if (oisHostname == null && oisAddr == null)
throw new InvalidObjectException("hostname and addr " +
"can't both be null");
InetSocketAddressHolder h = new InetSocketAddressHolder(oisHostname,
oisAddr,
oisPort);
UNSAFE.putReference(this, FIELDS_OFFSET, h);
}
/**
* Throws {@code InvalidObjectException}, always.
* @throws ObjectStreamException always
*/
@java.io.Serial
private void readObjectNoData()
throws ObjectStreamException
{
throw new InvalidObjectException("Stream data required");
}
private static final jdk.internal.misc.Unsafe UNSAFE
= jdk.internal.misc.Unsafe.getUnsafe();
private static final long FIELDS_OFFSET
= UNSAFE.objectFieldOffset(InetSocketAddress.class, "holder");
/**
* Gets the port number.
*
* @return the port number.
*/
public final int getPort() {
return holder.getPort();
}
/**
* Gets the {@code InetAddress}.
*
* @return the InetAddress or {@code null} if it is unresolved.
*/
public final InetAddress getAddress() {
return holder.getAddress();
}
/**
* Gets the {@code hostname}.
* Note: This method may trigger a name service reverse lookup if the
* address was created with a literal IP address.
*
* @return the hostname part of the address.
*/
public final String getHostName() {
return holder.getHostName();
}
/**
* 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.
*
* @return the hostname, or String representation of the address.
* @since 1.7
*/
public final String getHostString() {
return holder.getHostString();
}
/**
* Checks whether the address has been resolved or not.
*
* @return {@code true} if the hostname couldn't be resolved into
* an {@code InetAddress}.
*/
public final boolean isUnresolved() {
return holder.isUnresolved();
}
/**
* Constructs a string representation of this InetSocketAddress.
* This string is constructed by calling {@link InetAddress#toString()}
* on the InetAddress and concatenating the port number (with a colon).
*
* If the address is an IPv6 address, the IPv6 literal is enclosed in
* square brackets, for example: {@code "localhost/[0:0:0:0:0:0:0:1]:80"}.
* If the address is {@linkplain #isUnresolved() unresolved},
* {@code
* To retrieve a string representation of the hostname or the address, use
* {@link #getHostString()}, rather than parsing the string returned by this
* {@link #toString()} method.
*
* @return a string representation of this object.
*/
@Override
public String toString() {
return holder.toString();
}
/**
* Compares this object against the specified object.
* The result is {@code true} if and only if the argument is
* not {@code null} and it represents the same address as
* this object.
*
* Two instances of {@code 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.
*
* @param obj the object to compare against.
* @return {@code true} if the objects are the same;
* {@code false} otherwise.
* @see java.net.InetAddress#equals(java.lang.Object)
*/
@Override
public final boolean equals(Object obj) {
if (obj == null || !(obj instanceof InetSocketAddress))
return false;
return holder.equals(((InetSocketAddress) obj).holder);
}
/**
* Returns a hashcode for this socket address.
*
* @return a hash code value for this socket address.
*/
@Override
public final int hashCode() {
return holder.hashCode();
}
}