de.tudarmstadt.lt.lm.app.StartRMI.java Source code

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Here is the source code for de.tudarmstadt.lt.lm.app.StartRMI.java

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/*
 *   Copyright 2013
 *
 *   Licensed 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 de.tudarmstadt.lt.lm.app;

import java.rmi.NoSuchObjectException;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
import java.rmi.server.UnicastRemoteObject;
import java.util.Arrays;
import java.util.Scanner;

import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.OptionBuilder;
import org.apache.commons.cli.Options;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import de.tudarmstadt.lt.utilities.cli.CliUtils;
import de.tudarmstadt.lt.utilities.cli.ExtendedGnuParser;

/**
 *
 * @author Steffen Remus
 */
public class StartRMI implements Runnable {

    private final static Logger LOG = LoggerFactory.getLogger(StartRMI.class);
    private final static String USAGE_HEADER = "Options:";

    public static void main(String[] args) {
        new StartRMI(args).run();
    }

    /**
     * default constructor
     * 
     * set necessary variables by using <code>new StartRMI(){{ _variable = value; ... }} </code>
     * 
     */
    public StartRMI() {
        /* NOTHING TO DO */ }

    @SuppressWarnings("static-access")
    public StartRMI(String[] args) {
        LOG.warn("This main is only for convencience and might be deprectated soon. Consider using {}.",
                StartLM.class.getName());
        Options opts = new Options();
        opts.addOption(OptionBuilder.withLongOpt("help").withDescription("Display help message.").create("?"));
        opts.addOption(OptionBuilder.withLongOpt("port").withArgName("port-number").hasArg().withDescription(String
                .format("specifies the port on which rmi registry listens (default: %d)", Registry.REGISTRY_PORT))
                .create("p"));

        try {
            CommandLine cmd = new ExtendedGnuParser(true).parse(opts, args);
            if (cmd.hasOption("help"))
                CliUtils.print_usage_quit(System.err, StartLM.class.getSimpleName(), opts, USAGE_HEADER, null, 0);
            _port = Integer.parseInt(cmd.getOptionValue("port", String.valueOf(Registry.REGISTRY_PORT)));

        } catch (Exception e) {
            LOG.error("{}: {}", e.getClass().getSimpleName(), e.getMessage());
            CliUtils.print_usage_quit(System.err, StartLM.class.getSimpleName(), opts, USAGE_HEADER,
                    String.format("%s: %s%n", e.getClass().getSimpleName(), e.getMessage()), 1);
        }
    }

    String readInput(String message) {
        String r = null;
        System.out.print(message);
        if (_stdin_scan.hasNextLine()) { // block thread
            r = _stdin_scan.nextLine();
            return r;
        }
        return null;
    }

    int _port;
    Scanner _stdin_scan;
    Registry _registry;

    /* (non-Javadoc)
     * @see java.lang.Runnable#run()
     */
    @Override
    public void run() {

        try {
            // create own registry, alternative: use 'rmiregistry' command in class output folder
            _registry = LocateRegistry.createRegistry(_port);
        } catch (Exception e) {
            LOG.error("Could not create regisry. ", e);
            return;
        }

        _stdin_scan = new Scanner(System.in);
        for (String input_line = null; (input_line = readInput(String.format(
                "+++%nRMI Registry running. What do you want to do?%n" + "Type ':l' to list connected services, %n"
                        + "Type ':q' to quit program. %n" + "$> "))) != null;) {

            if (input_line.isEmpty())
                continue;
            if (":q".equalsIgnoreCase(input_line))
                exit();
            if (":l".equalsIgnoreCase(input_line))
                try {
                    System.out.format("%s%n", Arrays.toString(_registry.list()));
                } catch (Exception e) {
                    /* */}
        }
    }

    void exit() {
        LOG.info("Exiting.");

        String[] rmi_bounded_apps = new String[0];
        try {
            rmi_bounded_apps = _registry.list();
            if (rmi_bounded_apps.length == 0) {
                UnicastRemoteObject.unexportObject(_registry, true);
                LOG.info("Stopped RMI server.");
                System.exit(0);
            }
        } catch (Exception e) {
            /* */}

        String input_line = null;
        while ((input_line = readInput(String.format(
                "App serves as RMI server for the following apps: %s.%nType 'y' if you really want to quit serving RMI, else type 'n': %n$> ",
                Arrays.toString(rmi_bounded_apps)))) == null)
            ;
        if ("y".equals(input_line.toLowerCase())) {
            try {
                UnicastRemoteObject.unexportObject(_registry, true);
            } catch (NoSuchObjectException e) {
                /* handle silently */ }
            LOG.info("Stopped RMI server.");
            System.exit(0);
        } else
            return;

        System.exit(0);
    }

}