* Not 100% sure of resulting delay... it may be multiplied by 3 in the end, since RMI may try three * ways: 1) socket 2) html 3) cgi (per Sun javadoc) *
* To use, just instantiate once within your JVM, prerably before any RMI code. (Additional attempts will throw exceptions.) *
* A map of proxy redirects, and/or a single default proxy is supported. * See setProxies() and setProxy() for more info. */ public class ASIRmiSocketFactory extends RMISocketFactory { private static final boolean debug = true; private static int timeoutMillis; private static InetAddress server; private static Map proxies; private static String proxy; /** * Creates a new instance of ASIRmiSocketFactory with a default 10-sec timeout, * and installs itself as the new default; can only happen once, else an * exception is thrown. */ public ASIRmiSocketFactory() throws IOException { this(null, 10000); } /** * Creates a new instance of ASIRmiSocketFactory, and installs itself as the new default; * can only happen once, else an exception is thrown. * * @param server The InetAddress of the network interface on which to bind server * sockets; if null, will bind to all interfaces. */ public ASIRmiSocketFactory(InetAddress server, int timeoutMillis) throws IOException { this.timeoutMillis = timeoutMillis; this.server = server; RMISocketFactory.setSocketFactory(this); } /** Implements RMISocketFactory by just creating a normal ServerSocket; same as default impl? */ public ServerSocket createServerSocket(int port) throws IOException { ServerSocket ss = new ServerSocket(port, 50, server); return ss; } /** * Implements RMISocketFactory by creating a Socket, but connecting with a short timeout; * 5-sec(may act like 15-sec... see class javadoc) or as defined in the constructor. *
* May replace the given host with a proxy if configured; first the proxies * map is checked; if no match there then the default proxy is used if configured; * otherwise no host replacement is made. */ public Socket createSocket(String host, int port) throws IOException { // Replace host with proxy, if defined via lookup map or default proxy... if (proxies != null) { String p = proxies.get(host).toString(); if (p != null) { host = p; } else if (proxy != null) host = proxy; } else if (proxy != null) { host = proxy; } Socket s = new Socket(); SocketAddress sa = new InetSocketAddress(host, port); try { s.connect(sa, timeoutMillis); } catch (IOException ioe) // timeout { throw ioe; } return s; } /** * Set an optional lookup map for defining hosts that should be routed * through a proxy. For example, when a server is protected behind a NAT * router, an external client may be able to connect to the server's RMI * registry through the router, but any stub addresses returned by the RMI * registry will reference the server's real address (not reachable directly * by the client). So a proxy map can replace the server's address with the * NAT address. *
* Note that traditionally, the java.rmi.server.hostname property could be * set to advertise the NAT address instead of the protected address on the * server's RMI Registry JVM, but if that same Registry is used * by other servers on the same protected network, then their stub connections * would be routed through the external NAT address, which is not efficient * or secure. Note that this is only an issue in a client-server system * where there are multiple networked servers. A stand-alone system is fine just * using the java.rmi.server.hostname property. *
* This method may be called anytime after construction; subsequent calls * overwrite any previous setting. Note that this RMISocketFactory is * essentially static in the JVM, so any proxy changes affect all users. * * @param proxies A Map, possibly null, whose keys are the String IP addresses * of the protected servers; the values are the associated public NAT addresses. * The proxy map will be used whenever the createSocket() method is called. * The proxies do not affect the createServerSocket() method. */ public void setProxies(Map proxies) { this.proxies = proxies; } /** * Optional: Set a default proxy for all calls to createSocket(), replacing any * host passed to that call; may be overridden if * a proxies Map contains a proxy for the given host. * See the javadoc for setProxies() for more background info. *
* This method may be called anytime after construction; subsequent calls * overwrite any previous setting. Note that this RMISocketFactory is * essentially static in the JVM, so any proxy changes affect all users. */ public void setProxy(String proxy) { this.proxy = proxy; } }