Class 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 performs a three-tiered approach to creating client sockets. First, a direct socket connection to the remote VM is attempted. If that fails (due to a firewall), the runtime uses HTTP with the explicit port number of the server. If the firewall does not allow this type of communication, then HTTP to a cgi-bin script on the server is used to POST the RMI call. The HTTP tunneling mechanisms are disabled by default. This behavior is controlled by the java.rmi.server.disableHttp property, whose default value is true. Setting this property's value to false will enable the HTTP tunneling mechanisms.

Deprecated: HTTP Tunneling. The HTTP tunneling mechanisms described above, specifically HTTP with an explicit port and HTTP to a cgi-bin script, are deprecated. These HTTP tunneling mechanisms are subject to removal in a future release of the platform.

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:
JDK1.1

Constructors

Constructor and Description
RMISocketFactory()

Constructs an RMISocketFactory.

Methods

Modifier and Type Method and 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 inherited from class java.lang.Object

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

Constructors

RMISocketFactory

public RMISocketFactory()

Constructs an RMISocketFactory.

Since:
JDK1.1

Methods

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:
JDK1.1

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:
JDK1.1

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. Note: The RMISocketFactory may only be set if the current security manager allows setting a socket factory; if disallowed, a SecurityException will be thrown.

Parameters:
fac - the socket factory
Throws:
IOException - if the RMI socket factory is already set
SecurityException - if a security manager exists and its checkSetFactory method doesn't allow the operation.
Since:
JDK1.1
See Also:
getSocketFactory(), SecurityManager.checkSetFactory()

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:
JDK1.1
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:
JDK1.1

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.

If there is a security manager, this method first calls the security manager's checkSetFactory method to ensure the operation is allowed. This could result in a SecurityException.

Parameters:
fh - the failure handler
Throws:
SecurityException - if a security manager exists and its checkSetFactory method doesn't allow the operation.
Since:
JDK1.1
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:
JDK1.1
See Also:
setFailureHandler(RMIFailureHandler)

© 1993, 2020, Oracle and/or its affiliates. All rights reserved.
Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.
https://docs.oracle.com/javase/8/docs/api/java/rmi/server/RMISocketFactory.html