Server

package dslab.test;

import java.io.BufferedReader;
import java.io.Closeable;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.rmi.NoSuchObjectException;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
import java.rmi.server.UnicastRemoteObject;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * NOTE: DO *NOT* CHANGE THIS FILE!
 */
public class Server implements Runnable, Closeable, IServerRemote {

    private int tcpPort;
    private ServerSocket serverSocket;
    private Socket clientSocket;

    private int registryPort;
    private String bindingName;
    private Registry registry;

    private List<String> solvedStages = new ArrayList<String>();

    public Server(int tcpPort, int registryPort, String bindingName) {
        this.tcpPort = tcpPort;
        this.registryPort = registryPort;
        this.bindingName = bindingName;
    }

    public void init() {
        try {
            registry = LocateRegistry.createRegistry(registryPort);

            IServerRemote remote = (IServerRemote) UnicastRemoteObject
                    .exportObject(this, 0);

            registry.bind(bindingName, remote);

            serverSocket = new ServerSocket(tcpPort);
        } catch (Exception e) {
            try {
                close();
            } catch (IOException e1) {
            }
        }
    }

    @Override
    public String bye() {
        solvedStages.add(BYE[0]);
        return "!see_you";
    }

    @Override
    public void run() {

        try {
            clientSocket = serverSocket.accept();

            solvedStages.add(HELLO[0]);

            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    clientSocket.getInputStream()));
            PrintWriter writer = new PrintWriter(
                    clientSocket.getOutputStream(), true);

            String request;
            while ((request = reader.readLine()) != null) {
                if (request.equals("!hello")) {
                    solvedStages.add(HELLO[1]);
                    writer.println("!welcome");
                } else
                    writer.println("!wrongRequest");
            }
            solvedStages.add(HELLO[2]);

        } catch (IOException e) {
            try {
                close();
            } catch (IOException e1) {
            }
        }
    }

    @Override
    public void close() throws IOException {

        if (serverSocket != null && !serverSocket.isClosed())
            serverSocket.close();

        if (clientSocket != null && !clientSocket.isClosed())
            clientSocket.close();

        try {
            UnicastRemoteObject.unexportObject(this, true);
        } catch (NoSuchObjectException e) {
        }

        if (registry != null) {
            try {
                // unbind remote object
                registry.unbind(bindingName);

                // stop registry
                UnicastRemoteObject.unexportObject(registry, true);
            } catch (Exception e) {
            }
        }
    }

    public Result getResult(String id) {
        boolean succeeded = true;
        String message = "\nYou didn't pass the following stages: \n";
        String[] stages = idMap.get(id);
        for (String stage : stages) {
            if (!solvedStages.contains(stage)) {
                succeeded = false;
                message += "* " + stageMap.get(stage) + "\n";
            }
        }

        return new Result(succeeded, message);
    }

    private static Map<String, String> stageMap = new HashMap<String, String>();
    private static Map<String, String[]> idMap = new HashMap<String, String[]>();
    private final static String[] HELLO = { "hello_01", "hello_02", "hello_03"};
    private final static String[] BYE = { "bye_01" };

    static {
        idMap.put("hello", HELLO);
        idMap.put("bye", BYE);

        stageMap.put(HELLO[0], "connect to server");
        stageMap.put(HELLO[1], "send !hello to server");
        stageMap.put(HELLO[2], "close connection");

        stageMap.put(BYE[0], "invoke bye() on ServerRemote");
    }

}