chapters.mdc.NumberCruncherClient Maven / Gradle / Ivy

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/**
 * Logback: the reliable, generic, fast and flexible logging framework.
 * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
 *
 * This program and the accompanying materials are dual-licensed under
 * either the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation
 *
 *   or (per the licensee's choosing)
 *
 * under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation.
 */
package chapters.mdc;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.rmi.Naming;
import java.rmi.RemoteException;

/**
 * NumberCruncherClient is a simple client for factoring integers. A
 * remote NumberCruncher is contacted and asked to factor an
 * integer. The factors returned by the {@link NumberCruncherServer}
 * are displayed on the screen.
 * */
public class NumberCruncherClient {
    public static void main(String[] args) {
        if (args.length == 1) {
            try {
                String url = "rmi://" + args[0] + "/Factor";
                NumberCruncher nc = (NumberCruncher) Naming.lookup(url);
                loop(nc);
            } catch (Exception e) {
                e.printStackTrace();
            }
        } else {
            usage("Wrong number of arguments.");
        }
    }

    static void usage(String msg) {
        System.err.println(msg);
        System.err.println("Usage: java chapters.mdc.NumberCruncherClient HOST\n" + "   where HOST is the machine where the NumberCruncherServer is running.");
        System.exit(1);
    }

    static void loop(NumberCruncher nc) {
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        int i = 0;

        while (true) {
            System.out.print("Enter a number to factor, '-1' to quit: ");

            try {
                i = Integer.parseInt(in.readLine());
            } catch (Exception e) {
                e.printStackTrace();
            }

            if (i == -1) {
                System.out.print("Exiting loop.");

                return;
            } else {
                try {
                    System.out.println("Will attempt to factor " + i);

                    int[] factors = nc.factor(i);
                    System.out.print("The factors of " + i + " are");

                    for (int k = 0; k < factors.length; k++) {
                        System.out.print(" " + factors[k]);
                    }

                    System.out.println(".");
                } catch (RemoteException e) {
                    System.err.println("Could not factor " + i);
                    e.printStackTrace();
                }
            }
        }
    }
}