# Class RMISocketFactory

java.lang.Object
java.rmi.server.RMISocketFactory

All Implemented Interfaces:
  `RMIClientSocketFactory, RMIServerSocketFactory`

public abstract class RMISocketFactory extends Object implements RMIClientSocketFactory, RMIServerSocketFactory
An `RMISocketFactory` instance is used by the RMI runtime in order to obtain client and server sockets for RMI calls. An application may use the `setSocketFactory` method to request that the RMI runtime use its socket factory instance instead of the default implementation.

The default socket factory implementation creates a direct socket connection to the remote host.

The default socket factory implementation creates server sockets that are bound to the wildcard address, which accepts requests from all network interfaces.

Implementation Note:

  You can use the `RMISocketFactory` class to create a server socket that is bound to a specific address, restricting the origin of requests. For example, the following code implements a socket factory that binds server sockets to an IPv4 loopback address. This restricts RMI to processing requests only from the local host.

          class LoopbackSocketFactory extends RMISocketFactory {
              public ServerSocket createServerSocket(int port) throws IOException {
                  return new ServerSocket(port, 5, InetAddress.getByName("127.0.0.1"));
              }

              public Socket createSocket(String host, int port) throws IOException {
                  // just call the default client socket factory
                  return RMISocketFactory.getDefaultSocketFactory()
                                         .createSocket(host, port);
              }
          }

          // ...

          RMISocketFactory.setSocketFactory(new LoopbackSocketFactory());

  Set the `java.rmi.server.hostname` system property to `127.0.0.1` to ensure that the generated stubs connect to the right network interface.
Since:
  1.1

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `RMISocketFactory()`
  Constructs an `RMISocketFactory`.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `abstract ServerSocket`
  `createServerSocket(int port)`
  Create a server socket on the specified port (port 0 indicates an anonymous port).
  `abstract Socket`
  `createSocket(String host, int port)`
  Creates a client socket connected to the specified host and port.
  `static RMISocketFactory`
  `getDefaultSocketFactory()`
  Returns a reference to the default socket factory used by this RMI implementation.
  `static RMIFailureHandler`
  `getFailureHandler()`
  Returns the handler for socket creation failure set by the `setFailureHandler` method.
  `static RMISocketFactory`
  `getSocketFactory()`
  Returns the socket factory set by the `setSocketFactory` method.
  `static void`
  `setFailureHandler(RMIFailureHandler fh)`
  Sets the failure handler to be called by the RMI runtime if server socket creation fails.
  `static void`
  `setSocketFactory(RMISocketFactory fac)`
  Set the global socket factory from which RMI gets sockets (if the remote object is not associated with a specific client and/or server socket factory).

  ### Methods declared in class Object

  `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`
  Modifier and Type
  Method
  Description
  `protected Object`
  `clone()`
  Creates and returns a copy of this object.
  `boolean`
  `equals(Object obj)`
  Indicates whether some other object is "equal to" this one.
  `protected void`
  `finalize()`
  Deprecated, for removal: This API element is subject to removal in a future version.
  Finalization is deprecated and subject to removal in a future release.
  `final Class<?>`
  `getClass()`
  Returns the runtime class of this `Object`.
  `int`
  `hashCode()`
  Returns a hash code value for this object.
  `final void`
  `notify()`
  Wakes up a single thread that is waiting on this object's monitor.
  `final void`
  `notifyAll()`
  Wakes up all threads that are waiting on this object's monitor.
  `String`
  `toString()`
  Returns a string representation of the object.
  `final void`
  `wait()`
  Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
  `final void`
  `wait(long timeoutMillis)`
  Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
  `final void`
  `wait(long timeoutMillis, int nanos)`
  Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

- ## Constructor Details

  - ### RMISocketFactory

    public RMISocketFactory()
    Constructs an `RMISocketFactory`.
    Since:
      1.1

- ## Method Details

  - ### createSocket

    public abstract Socket createSocket(String host, int port) throws IOException
    Creates a client socket connected to the specified host and port.
    Specified by:
      `createSocket` in interface `RMIClientSocketFactory`
    Parameters:
      `host` - the host name
      `port` - the port number
    Returns:
      a socket connected to the specified host and port.
    Throws:
      `IOException` - if an I/O error occurs during socket creation
    Since:
      1.1

  - ### createServerSocket

    public abstract ServerSocket createServerSocket(int port) throws IOException
    Create a server socket on the specified port (port 0 indicates an anonymous port).
    Specified by:
      `createServerSocket` in interface `RMIServerSocketFactory`
    Parameters:
      `port` - the port number
    Returns:
      the server socket on the specified port
    Throws:
      `IOException` - if an I/O error occurs during server socket creation
    Since:
      1.1

  - ### setSocketFactory

    public static void setSocketFactory(RMISocketFactory fac) throws IOException
    Set the global socket factory from which RMI gets sockets (if the remote object is not associated with a specific client and/or server socket factory). The RMI socket factory can only be set once.
    Parameters:
      `fac` - the socket factory
    Throws:
      `IOException` - if the RMI socket factory is already set
    Since:
      1.1
    See Also:
      - `getSocketFactory()`

  - ### getSocketFactory

    public static RMISocketFactory getSocketFactory()
    Returns the socket factory set by the `setSocketFactory` method. Returns `null` if no socket factory has been set.
    Returns:
      the socket factory
    Since:
      1.1
    See Also:
      - `setSocketFactory(RMISocketFactory)`

  - ### getDefaultSocketFactory

    public static RMISocketFactory getDefaultSocketFactory()
    Returns a reference to the default socket factory used by this RMI implementation. This will be the factory used by the RMI runtime when `getSocketFactory` returns `null`.
    Returns:
      the default RMI socket factory
    Since:
      1.1

  - ### setFailureHandler

    public static void setFailureHandler(RMIFailureHandler fh)
    Sets the failure handler to be called by the RMI runtime if server socket creation fails. By default, if no failure handler is installed and server socket creation fails, the RMI runtime does attempt to recreate the server socket.
    Parameters:
      `fh` - the failure handler.
    Since:
      1.1
    See Also:
      - `getFailureHandler()`
      - `RMIFailureHandler.failure(Exception)`

  - ### getFailureHandler

    public static RMIFailureHandler getFailureHandler()
    Returns the handler for socket creation failure set by the `setFailureHandler` method.
    Returns:
      the failure handler
    Since:
      1.1
    See Also:
      - `setFailureHandler(RMIFailureHandler)`