examples/NumberCruncherClient.java

/*
 * Copyright (C) The Apache Software Foundation. All rights reserved.
 *
 * This software is published under the terms of the Apache Software
 * License version 1.1, a copy of which has been included with this
 * distribution in the LICENSE.APL file.  */

package org.apache.log4j.examples;

import java.rmi.Remote;
import java.rmi.server.UnicastRemoteObject;
import java.rmi.RemoteException;
import java.rmi.Naming;
import java.util.Vector;
import java.io.*;

/**
   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.

   <p>See <a href=doc-files/NumberCruncherClient.java>source</a> code of 
   <code>NumberCruncherClient</code> for more details.

   <pre>
   <b>Usage:</b> java  org.apache.log4j.examples.NumberCruncherClient HOST
    &nbsp;&nbsp;&nbsp;&nbsp;where HOST is the machine where the NumberCruncherServer is running
   </pre>
   
   <p>Note that class files for the example code is not included in
   any of the distributed log4j jar files. You will have to add the
   directory <code>/dir-where-you-unpacked-log4j/classes</code> to
   your classpath before trying out the examples.

   @author Ceki G&uuml;lc&uuml;
   
 */
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 org.apache.log4j.examples.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();
	}
      }
    }
  }
}