mudclient.java

java 的164个例子的源代码,包括了 很多方面,供包括了19个方面的 源代码

/*
 * Copyright (c) 2000 David Flanagan.  All rights reserved.
 * This code is from the book Java Examples in a Nutshell, 2nd Edition.
 * It is provided AS-IS, WITHOUT ANY WARRANTY either expressed or implied.
 * You may study, use, and modify it for any non-commercial purpose.
 * You may distribute it non-commercially as long as you retain this notice.
 * For a commercial use license, or to purchase the book (recommended),
 * visit http://www.davidflanagan.com/javaexamples2.
 */
package com.davidflanagan.examples.rmi;
import java.rmi.*;
import java.rmi.server.*;
import java.rmi.registry.*;
import java.io.*;
import java.util.*;
import com.davidflanagan.examples.rmi.Mud.*;

/**
 * This class is a client program for the MUD.  The main() method sets up 
 * a connection to a RemoteMudServer, gets the initial RemoteMudPlace object,
 * and creates a MudPerson object to represent the user in the MUD.  Then it 
 * calls runMud() to put the person in the place, begins processing
 * user commands.  The getLine() and getMultiLine() methods are convenience
 * methods used throughout to get input from the user.
 **/
public class MudClient {
    /**
     * The main program.  It expects two or three arguments:
     *   0) the name of the host on which the mud server is running
     *   1) the name of the MUD on that host
     *   2) the name of a place within that MUD to start at (optional).
     *
     * It uses the Naming.lookup() method to obtain a RemoteMudServer object
     * for the named MUD on the specified host.  Then it uses the getEntrance()
     * or getNamedPlace() method of RemoteMudServer to obtain the starting
     * RemoteMudPlace object.  It prompts the user for a their name and 
     * description, and creates a MudPerson object.  Finally, it passes
     * the person and the place to runMud() to begin interaction with the MUD.
     **/
    public static void main(String[] args) {
        try {
            String hostname = args[0]; // Each MUD is uniquely identified by a 
            String mudname = args[1];  //   host and a MUD name.
            String placename = null;   // Each place in a MUD has a unique name
            if (args.length > 2) placename = args[2];
	    
            // Look up the RemoteMudServer object for the named MUD using
            // the default registry on the specified host.  Note the use of
            // the Mud.mudPrefix constant to help prevent naming conflicts
            // in the registry.
            RemoteMudServer server = 
                (RemoteMudServer)Naming.lookup("rmi://" + hostname + "/" +
					       Mud.mudPrefix + mudname);

            // If the user did not specify a place in the mud, use
            // getEntrance() to get the initial place.  Otherwise, call
            // getNamedPlace() to find the initial place.
            RemoteMudPlace location = null;
            if (placename == null) location = server.getEntrance();
            else location = (RemoteMudPlace) server.getNamedPlace(placename);
	    
            // Greet the user and ask for their name and description.
            // This relies on getLine() and getMultiLine() defined below.
            System.out.println("Welcome to " + mudname);
            String name = getLine("Enter your name: ");
            String description = getMultiLine("Please describe what " +
					  "people see when they look at you:");

            // Define an output stream that the MudPerson object will use to
            // display messages sent to it to the user.  We'll use the console.
            PrintWriter myout = new PrintWriter(System.out);
	    
            // Create a MudPerson object to represent the user in the MUD.
            // Use the specified name and description, and the output stream.
            MudPerson me = new MudPerson(name, description, myout);
	    
            // Lower this thread's priority one notch so that broadcast
            // messages can appear even when we're blocking for I/O.  This is
            // necessary on the Linux platform, but may not be necessary on all
            // platforms.
            int pri = Thread.currentThread().getPriority();
            Thread.currentThread().setPriority(pri-1);
	    
            // Finally, put the MudPerson into the RemoteMudPlace, and start
            // prompting the user for commands.
            runMud(location, me);
        }
        // If anything goes wrong, print a message and exit.
        catch (Exception e) {
            System.out.println(e);
            System.out.println("Usage: java MudClient <host> <mud> [<place>]");
            System.exit(1);
        }
    }

    /**
     * This method is the main loop of the MudClient.  It places the person
     * into the place (using the enter() method of RemoteMudPlace).  Then it
     * calls the look() method to describe the place to the user, and enters a
     * command loop to prompt the user for a command and process the command
     **/
    public static void runMud(RemoteMudPlace entrance, MudPerson me) 
	throws RemoteException
    {
        RemoteMudPlace location = entrance;  // The current place
        String myname = me.getName();        // The person's name
        String placename = null;             // The name of the current place
        String mudname = null;             // The name of the mud of that place

        try { 
            // Enter the MUD
            location.enter(me, myname, myname + " has entered the MUD."); 
            // Figure out where we are (for the prompt)
            mudname = location.getServer().getMudName();
            placename = location.getPlaceName();
            // Describe the place to the user
            look(location);
        }
        catch (Exception e) {
            System.out.println(e);
            System.exit(1);
        }
	
        // Now that we've entered the MUD, begin a command loop to process
        // the user's commands.  Note that there is a huge block of catch
        // statements at the bottom of the loop to handle all the things that
        // could go wrong each time through the loop.
        for(;;) {  // Loop until the user types "quit"
            try {    // Catch any exceptions that occur in the loop
                // Pause just a bit before printing the prompt, to give output
                // generated indirectly by the last command a chance to appear.
                try { Thread.sleep(200); } catch (InterruptedException e) {}

                // Display a prompt, and get the user's input
                String line = getLine(mudname + '.' + placename + "> ");
		
                // Break the input into a command and an argument that consists
                // of the rest of the line.  Convert the command to lowercase.
                String cmd, arg;
                int i = line.indexOf(' ');
                if (i == -1) { cmd = line; arg = null; }
                else {
                    cmd = line.substring(0, i).toLowerCase();
                    arg = line.substring(i+1);
                }
                if (arg == null) arg = "";
		
                // Now go process the command.  What follows is a huge repeated
                // if/else statement covering each of the commands supported by
                // this client.  Many of these commands simply invoke one of
                // the remote methods of the current RemoteMudPlace object.
                // Some have to do a bit of additional processing.

                // LOOK: Describe the place and its things, people, and exits
                if (cmd.equals("look")) look(location);
                // EXAMINE: Describe a named thing
                else if (cmd.equals("examine")) 
                    System.out.println(location.examineThing(arg));
                // DESCRIBE: Describe a named person
                else if (cmd.equals("describe")) {
                    try { 
                        RemoteMudPerson p = location.getPerson(arg);
                        System.out.println(p.getDescription()); 
                    }
                    catch(RemoteException e) {
                        System.out.println(arg + " is having technical " +
					   "difficulties. No description " +
					   "is available.");
                    }
                }
                // GO: Go in a named direction
                else if (cmd.equals("go")) {
                    location = location.go(me, arg);
                    mudname = location.getServer().getMudName();
                    placename = location.getPlaceName();
                    look(location);
                }
                // SAY: Say something to everyone 
                else if (cmd.equals("say")) location.speak(me, arg);
                // DO: Do something that will be described to everyone
                else if (cmd.equals("do")) location.act(me, arg);
                // TALK: Say something to one named person
                else if (cmd.equals("talk")) {
                    try {
                        RemoteMudPerson p = location.getPerson(arg);
                        String msg = getLine("What do you want to say?: ");
                        p.tell(myname + " says \"" + msg + "\"");
                    }
                    catch (RemoteException e) {
                        System.out.println(arg + " is having technical " +
			   	         "difficulties. Can't talk to them.");
                    }
                }
                // CHANGE: Change my own description 
                else if (cmd.equals("change"))
                    me.setDescription(
			    getMultiLine("Describe yourself for others: "));
                // CREATE: Create a new thing in this place
                else if (cmd.equals("create")) {
                    if (arg.length() == 0)
                        throw new IllegalArgumentException("name expected");
                    String desc = getMultiLine("Please describe the " +
					       arg + ": ");
                    location.createThing(me, arg, desc);
                }
                // DESTROY: Destroy a named thing
                else if (cmd.equals("destroy")) location.destroyThing(me, arg);
                // OPEN: Create a new place and connect this place to it
                // through the exit specified in the argument.
                else if (cmd.equals("open")) {
                    if (arg.length() == 0) 
                      throw new IllegalArgumentException("direction expected");
                    String name = getLine("What is the name of place there?: ");
                    String back = getLine("What is the direction from " + 
					  "there back to here?: ");
                    String desc = getMultiLine("Please describe " +