ChatClient.java ChatServer.java Connection.java Hosts.txt

[Canito07]

ChatServer.java

Código:

import java.io.*;
import java.net.*;
import java.util.*;
import java.applet.*;

public class ChatServer {

  public static void main(String[] args) {
    ChatServer cs = new ChatServer();
    cs.go();
  }

  public final static int DEFAULT_PORT = 2000;
  public final static int DEFAULT_MAX_BACKLOG = 5;
  public final static int DEFAULT_MAX_CONNECTIONS = 20;
  public final static String DEFAULT_HOST_FILE = "hosts.txt";
  public final static String DEFAULT_SOUND_FILE = "file:gong.au";
  public final static String MAGIC = "Yippy Skippy";

  private String magic = MAGIC;

  private int port = DEFAULT_PORT;
  private int backlog = DEFAULT_MAX_BACKLOG;
  private int numConnections = 0;
  private int maxConnections = DEFAULT_MAX_CONNECTIONS;
  private String hostfile = DEFAULT_HOST_FILE;
  private String soundfile = DEFAULT_SOUND_FILE;
  private List<Connection> connections = null;
  private AudioClip connectSound = null;
  private Map<String,String> hostToStudentMap = null;

  //
  // Methods for the Connection class
  //

  String getMagicPassphrase() {
    return magic;
  }

  String getStudentName(String host) {
    return hostToStudentMap.get(host);
  }

  void sendToAllClients(String message) {
    for ( Connection c : connections ) {
      c.sendMessage(message);
    }
  }

  void playMagicSound() {
    if ( connectSound != null ) {
      connectSound.play();
    }
  }

  synchronized void closeConnection(Connection connection) {
    connections.remove(connection);
    numConnections--;
    notify();
  }

  //
  // Private methods
  //

  private void go() {
    String portString = System.getProperty("port");
    if (portString != null) port = Integer.parseInt(portString);
    this.port = port;

    String backlogString = System.getProperty("backlog");
    if (backlogString != null) backlog = Integer.parseInt(backlogString);

    String hostFileString = System.getProperty("hostfile");
    if (hostFileString != null) hostfile = hostFileString;

    String soundFileString = System.getProperty("soundfile");
    if (soundFileString != null) soundfile = soundFileString;

    String magicString = System.getProperty("magic");
    if (magicString != null) magic = magicString;

    String connections = System.getProperty("connections");
    if (connections != null) maxConnections = Integer.parseInt(connections);

    this.connections = new ArrayList<Connection>(maxConnections);
    this.hostToStudentMap = new HashMap<String,String>(15);

    System.out.println("Server settings:\n\tPort="+port+"\n\tMax Backlog="+
                       backlog+"\n\tMax Connections="+maxConnections+
		       "\n\tHost File="+hostfile+"\n\tSound File="+soundfile);

    createHostList();

    try {
      URL sound = new URL(soundfile);
      connectSound = Applet.newAudioClip(sound);
    } catch(Exception e) {
      e.printStackTrace();
    }

    // Begin the processing cycle
    processRequests();
  }

  private void createHostList() {
    File hostFile = new File(hostfile);
    try {
      System.out.println("Attempting to read hostfile hosts.txt: ");
      FileInputStream fis = new FileInputStream(hostFile);
      InputStreamReader isr = new InputStreamReader(fis);
      BufferedReader br = new BufferedReader(isr);
      String aLine = null;
      while((aLine = br.readLine()) != null) {
	int spaceIndex = aLine.indexOf(' ');
	if (spaceIndex == -1) {
	  System.out.println("Invalid line in host file: "+aLine);
	  continue;
	}
	String host = aLine.substring(0,spaceIndex);
	String student = aLine.substring(spaceIndex+1);
	System.out.println("Read: "+student+"@"+host);
	hostToStudentMap.put(host,student);
      }
    } catch(Exception e) {
      e.printStackTrace();
    }
  }          

  private void processRequests() {
    ServerSocket serverSocket = null;
    Socket communicationSocket;    

    try {
      System.out.println("Attempting to start server...");
      serverSocket = new ServerSocket(port,backlog);
    } catch (IOException e) { 
      System.out.println("Error starting server: Could not open port "+port);
      e.printStackTrace();
      System.exit(-1);
    }
    System.out.println ("Started server on port "+port);

    // Run the listen/accept loop forever
    while (true) {
      try {
        // Wait here and listen for a connection
        communicationSocket = serverSocket.accept();
        handleConnection(communicationSocket);
      } catch (Exception e) { 
        System.out.println("Unable to spawn child socket.");
        e.printStackTrace();
      }
    }
  }

  private synchronized void handleConnection(Socket connection) {
    while (numConnections == maxConnections) {
      try {
	wait();
      } catch(Exception e) { 
	e.printStackTrace();
      }
    }
    numConnections++;
    Connection con = new Connection(this, connection);
    Thread t = new Thread(con);
    t.start();
    connections.add(con);
  }
}

Connection.java

Código:

import java.io.*;
import java.net.*;

class Connection implements Runnable {

  ChatServer server = null;
  private Socket communicationSocket = null;
  private OutputStreamWriter out = null;
  private BufferedReader in = null;

  public Connection(ChatServer server, Socket s) {
    this.server = server;
    this.communicationSocket = s;
  }       

  public void sendMessage(String message) {
    try {
      out.write(message);
      out.flush();
    } catch(Exception e) {
      e.printStackTrace();
    }
  }

  public void run() {
    OutputStream socketOutput = null;
    InputStream socketInput = null;
    String magic = server.getMagicPassphrase();

    try {
      socketOutput = communicationSocket.getOutputStream();
      out = new OutputStreamWriter(socketOutput);
      socketInput = communicationSocket.getInputStream();
      in = new BufferedReader(new InputStreamReader(socketInput));

        
      InetAddress address = communicationSocket.getInetAddress();
      String hostname = address.getHostName();

      String welcome = 
	"Connection made from host: "+hostname+"\nEverybody say hello";
      String student = server.getStudentName(hostname);
      if (student != null) welcome += " to "+student;
      welcome+="!\n";
      server.sendToAllClients(welcome);
      System.out.println("Connection made "+student+"@"+hostname);
      sendMessage("Welcome "+student+" the passphrase is "+magic+"\n");
      String input = null;

      while ((input = in.readLine()) != null) {
	if (input.indexOf(magic) != -1) {
	  server.playMagicSound();
	  sendMessage("Congratulations "+student+" you sent the passphrase!\n");
	  System.out.println(student+" sent the passphrase!");
	} else {
	  server.sendToAllClients(input+"\n");
	}
      }
    } catch(Exception e) {
      e.printStackTrace(System.err);
    } finally {
      try {
	if (in != null) in.close();
	if (out != null) out.close();
	communicationSocket.close();
      }  catch(Exception e) {
	e.printStackTrace();
      }
      server.closeConnection(this);
    }
  }
}

hosts.txt

Código:

localhost Frank
192.168.1.100 Frank
192.168.1.102 Emily

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