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Commons Net example source code file (finger.java)

This example Commons Net source code file (finger.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Commons Net tags/keywords

fingerclient, fingerclient, inetaddress, io, ioexception, ioexception, net, network, string, string, unknownhostexception, unknownhostexception

The Commons Net finger.java source code

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package examples.unix;

import java.io.IOException;
import java.net.InetAddress;
import java.net.UnknownHostException;

import org.apache.commons.net.finger.FingerClient;

/***
 * This is an example of how you would implement the finger command
 * in Java using NetComponents.  The Java version is much shorter.
 * But keep in mind that the Unix finger command reads all sorts of
 * local files to output local finger information.  This program only
 * queries the finger daemon.
 * <p>
 * The -l flag is used to request long output from the server.
 * <p>
 ***/
public final class finger
{

    public static final void main(String[] args)
    {
        boolean longOutput = false;
        int arg = 0, index;
        String handle, host;
        FingerClient finger;
        InetAddress address = null;

        // Get flags.  If an invalid flag is present, exit with usage message.
        while (arg < args.length && args[arg].startsWith("-"))
        {
            if (args[arg].equals("-l"))
                longOutput = true;
            else
            {
                System.err.println("usage: finger [-l] [[[handle][@<server>]] ...]");
                System.exit(1);
            }
            ++arg;
        }


        finger = new FingerClient();
        // We want to timeout if a response takes longer than 60 seconds
        finger.setDefaultTimeout(60000);

        if (arg >= args.length)
        {
            // Finger local host

            try
            {
                address = InetAddress.getLocalHost();
            }
            catch (UnknownHostException e)
            {
                System.err.println("Error unknown host: " + e.getMessage());
                System.exit(1);
            }

            try
            {
                finger.connect(address);
                System.out.print(finger.query(longOutput));
                finger.disconnect();
            }
            catch (IOException e)
            {
                System.err.println("Error I/O exception: " + e.getMessage());
                System.exit(1);
            }

            return ;
        }

        // Finger each argument
        while (arg < args.length)
        {

            index = args[arg].lastIndexOf("@");

            if (index == -1)
            {
                handle = args[arg];
                try
                {
                    address = InetAddress.getLocalHost();
                }
                catch (UnknownHostException e)
                {
                    System.err.println("Error unknown host: " + e.getMessage());
                    System.exit(1);
                }
            }
            else
            {
                handle = args[arg].substring(0, index);
                host = args[arg].substring(index + 1);

                try
                {
                    address = InetAddress.getByName(host);
                    System.out.println("[" + address.getHostName() + "]");
                }
                catch (UnknownHostException e)
                {
                    System.err.println("Error unknown host: " + e.getMessage());
                    System.exit(1);
                }
            }

            try
            {
                finger.connect(address);
                System.out.print(finger.query(longOutput, handle));
                finger.disconnect();
            }
            catch (IOException e)
            {
                System.err.println("Error I/O exception: " + e.getMessage());
                System.exit(1);
            }

            ++arg;
            if (arg != args.length)
                System.out.print("\n");
        }
    }
}

Other Commons Net examples (source code examples)

Here is a short list of links related to this Commons Net finger.java source code file:

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