UnsatisfiedLinkError running nio example code NBTimeServer

[Michael E Mercer]

Hello,

 > uname -a
FreeBSD 4.8-STABLE FreeBSD 4.8-STABLE #1: Sat May 31 21:15:33 EDT 2003  i386

 > java -version
java version "1.4.1-p3"
Java(TM) 2 Runtime Environment, Standard Edition (build
1.4.1-p3-mmercer_13_may_2003_19_57)
Java HotSpot(TM) Client VM (build 1.4.1-p3-mmercer_13_may_2003_19_57, mixed
mode)


When I compiled the example code below and tried to run it, I get the following
error...

 > java NBTimeServer
Exception in thread "main" java.lang.UnsatisfiedLinkError: init
        at sun.nio.ch.DevPollArrayWrapper.init(Native Method)
        at sun.nio.ch.DevPollArrayWrapper.<init>(DevPollArrayWrapper.java:59)
        at sun.nio.ch.DevPollSelectorImpl.<init>(DevPollSelectorImpl.java:54)
        at
sun.nio.ch.DevPollSelectorProvider.openSelector(DevPollSelectorProvider.java:18)

        at NBTimeServer.acceptConnections(NBTimeServer.java:67)
        at NBTimeServer.<init>(NBTimeServer.java:56)
        at NBTimeServer.main(NBTimeServer.java:120)

 > cat NBTimeServer.java
/*
 * @(#)NBTimeServer.java        1.4 01/12/13
 * A non blocking Internet time server implemented using
 * the New I/O (NIO) facilities added to J2SE v 1.4.
 *
 * Copyright 2001-2002 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met:
 *
 * -Redistributions of source code must retain the above copyright
 * notice, this  list of conditions and the following disclaimer.
 *
 * -Redistribution in binary form must reproduct the above copyright
 * notice, this list of conditions and the following disclaimer in
 * the documentation and/or other materials provided with the
 * distribution.
 *
 * Neither the name of Sun Microsystems, Inc. or the names of
 * contributors may be used to endorse or promote products derived
 * from this software without specific prior written permission.
 *
 * This software is provided "AS IS," without a warranty of any
 * kind. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND
 * WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY
 * EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY
 * DAMAGES OR LIABILITIES  SUFFERED BY LICENSEE AS A RESULT OF  OR
 * RELATING TO USE, MODIFICATION OR DISTRIBUTION OF THE SOFTWARE OR
 * ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE
 * FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT,
 * SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF
 * THE USE OF OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 *
 * You acknowledge that Software is not designed, licensed or
 * intended for use in the design, construction, operation or
 * maintenance of any nuclear facility.
 */

import java.io.*;
import java.nio.*;
import java.nio.channels.*;
import java.nio.channels.spi.*;
import java.net.*;
import java.util.*;

// Listen on a port for connections and write back the current time.
public class NBTimeServer {
    private static final int DEFAULT_TIME_PORT = 8900;

    // Constructor with no arguments creates a time server on default port.
    public NBTimeServer() throws Exception {
        acceptConnections(this.DEFAULT_TIME_PORT);
    }

    // Constructor with port argument creates a time server on specified port.
    public NBTimeServer(int port) throws Exception {
        acceptConnections(port);
    }

    // Accept connections for current time. Lazy Exception thrown.
    private static void acceptConnections(int port) throws Exception {
        // Selector for incoming time requests
        Selector acceptSelector = SelectorProvider.provider().openSelector();

        // Create a new server socket and set to non blocking mode
        ServerSocketChannel ssc = ServerSocketChannel.open();
        ssc.configureBlocking(false);

        // Bind the server socket to the local host and port

        InetAddress lh = InetAddress.getLocalHost();
        InetSocketAddress isa = new InetSocketAddress(lh, port);
        ssc.socket().bind(isa);

        // Register accepts on the server socket with the selector. This
        // step tells the selector that the socket wants to be put on the
        // ready list when accept operations occur, so allowing multiplexed
        // non-blocking I/O to take place.
        SelectionKey acceptKey = ssc.register(acceptSelector,
                                              SelectionKey.OP_ACCEPT);

        int keysAdded = 0;

        // Here's where everything happens. The select method will
        // return when any operations registered above have occurred, the
        // thread has been interrupted, etc.
        while ((keysAdded = acceptSelector.select()) > 0) {
            // Someone is ready for I/O, get the ready keys
            Set readyKeys = acceptSelector.selectedKeys();
            Iterator i = readyKeys.iterator();

            // Walk through the ready keys collection and process date requests.

            while (i.hasNext()) {
                SelectionKey sk = (SelectionKey)i.next();
                i.remove();
                // The key indexes into the selector so you
                // can retrieve the socket that's ready for I/O
                ServerSocketChannel nextReady =
                    (ServerSocketChannel)sk.channel();
                // Accept the date request and send back the date string
                Socket s = nextReady.accept().socket();
                // Write the current time to the socket
                PrintWriter out = new PrintWriter(s.getOutputStream(), true);
                Date now = new Date();
                out.println(now);
                out.close();
            }
        }
    }

    // Entry point.
    public static void main(String[] args) {
        // Parse command line arguments and
        // create a new time server (no arguments yet)
        try {
                NBTimeServer nbt = new NBTimeServer();
        } catch(Exception e) {
                e.printStackTrace();
        }
    }
}