user.java

WAP Push实现源码！

package push;

import members.Members;
import java.io.*;
import java.util.Hashtable;
import java.util.Vector;
import java.util.Enumeration;
import javax.servlet.http.*;

/**
 * Class User is a used to store push information for users logged in, i.e having an active session
 *
 * @version 1.0
 * @since 1.0
 * @see HttpSessionBindingListener
 */
public final class User implements HttpSessionBindingListener {

    /* vector of users who have currently a valid session (with push enabled WAP device). 
       Whenever the session becomes invalidated, the user object is removed from the vector. */
    private static final Vector usersOnline = new Vector();

    private HttpSession session = null;

    private final String name;

    private final String address;

    private final Hashtable properties; 

    /**
     * Creates a new <code>User</code> instance.
     *
     * @param name a <code>String</code> value
     * @param address a <code>String</code> value
     */
    public User(String name, String address) {
	this.name = name;
	this.address = address;
	properties = new Hashtable();
    }

    /**
     * Returns user name
     *
     * @return a <code>String</code> value
     */
    public String getName() {
	return (String)session.getAttribute("name");
    }

    /**
     * Returns date of birth 
     *
     * @return a <code>String</code> value
     */
    public String getDob() {
	return (String)session.getAttribute("dob");
    }

    /**
     * Returns user selected push services
     *
     * @return a <code>String</code> value
     */
    public String getPushServices() {
	return (String)session.getAttribute("pushservices");
    }

    /**
     * Returns the user's (client) address
     *
     * @return a <code>String</code> value
     */
    public String getAddress() {
	return address;
    }

    /**
     * Returns the user's (client) address. The address is of given type.
     *
     * @param addressType a <code>String</code> value (IPv4 or PLMN)
     * @return a <code>String</code> value
     */
    public String getAddress(String addressType) {
	if(addressType.equals("IPv4"))
	    return address;
	else if(addressType.equals("PLMN")) 
	    return Members.getPhoneNumber(getName());
	return null;
    }

    /**
     * Set a property with the user object
     *
     * @param name a <code>String</code> value
     * @param value a <code>String</code> value
     */
    public void setProperty(String name, Object value) {
	properties.put(name, value);
    }

    /**
     * Finds property object by given property name
     *
     * @param name a <code>String</code> value
     * @return an <code>Object</code> value
     */
    public Object getProperty(String name) {
	return properties.get(name);
    }

    /**
     * Returns users currently logged in
     *
     * @return a <code>Vector</code> value
     */
    public static Vector getUsersOnline() {
	return usersOnline;
    }

    /**
     * Finds user on the basis of given name
     *
     * @param name a <code>String</code> value
     * @return an <code>User</code> value
     * @exception Exception if an error occurs
     */
    public static User findUser(String name) throws Exception {
	synchronized(usersOnline) {
	    for(Enumeration e = usersOnline.elements(); e.hasMoreElements();) {
		User user = (User)e.nextElement();
		if(user.getName().equals(name)) return user;
	    }
	}
	return null;
    }

    /**
     * Notifies the User object that it is being bound to a session and 
     * identifies the session.
     *
     * @param event a <code>HttpSessionBindingEvent</code> value
     * @see HttpSessionBindingListener
     */
    public void valueBound(HttpSessionBindingEvent event) {
	session = event.getSession();
	synchronized(usersOnline) {
	    usersOnline.add(this);
	}
    }

    /**
     * Notifies the User object that it is being unbound from a session and 
     * identifies the session.
     *
     * @param event a <code>HttpSessionBindingEvent</code> value
     * @see HttpSessionBindingListener
     */
    public void valueUnbound(HttpSessionBindingEvent event) {
	synchronized(usersOnline) {
	    usersOnline.remove(this);
	    System.out.println("Session invalidated (max inactive time): user = " + name);
	}
    }

}