OnlineUser.java

package online_management;

import java.io.PrintWriter;
import java.net.InetAddress;
import java.util.GregorianCalendar;

/**
 * This class is used to identify an online user, that is a user connected to the server. Every user has a different
 * name from the others and, almost certainly, a different HashCode. This code is generated in the login phase, and
 * it's used to check if a message sent by a user comes really by him.
 *
 * @author Noris
 * @date 2015/03/30
 */
public class OnlineUser {

    private String username;
    private InetAddress ipAddress;
    private PrintWriter writer;
    private GregorianCalendar connectionDate;
    private volatile boolean polled;

    public OnlineUser(String username, InetAddress ipAddress) {
        this.username = username;
        this.ipAddress = ipAddress;
        connectionDate = new GregorianCalendar();
        polled = true;
    }

    public String getUsername() {
        return username;
    }

    public InetAddress getIpAddress() {
        return ipAddress;
    }

    /**
     * @return the date on which the user has logged in
     */
    public GregorianCalendar getConnectionDate() {
        return connectionDate;
    }

    /**
     * @return the connection time in milliseconds
     */
    public long getConnectionTime() {
        GregorianCalendar now = new GregorianCalendar();
        return now.getTimeInMillis() - connectionDate.getTimeInMillis();
    }

    /**
     * @return a different value for every online user
     */
    @Override
    public int hashCode() {
        return username.hashCode() * ipAddress.hashCode() * connectionDate.hashCode();
    }

    public void setOutStream(PrintWriter printWriter) {
        this.writer = printWriter;
    }

    public PrintWriter getOutStream() {
        return writer;
    }

    public boolean isPolled() {
        return polled;
    }

    public void setPolled(boolean polled) {
        this.polled = polled;
    }

}