DaapSession.java

/*
 * Digital Audio Access Protocol (DAAP) Library
 * Copyright (C) 2004-2010 Roger Kapsi
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.ardverk.daap;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

/**
 * A session object where session related information can be stored. It's
 * currently a bit overdesigned but we need the features maybe in the future.
 * 
 * @author Roger Kapsi
 */
public class DaapSession {

    private final long creationTime = System.currentTimeMillis();
    private final Map<String, Object> attributes = new HashMap<String, Object>();

    private final SessionId sessionId;
    private boolean valid;
    private long lastAccesedTime;
    private int maxInactiveTime;

    /**
     * Creates a new DaapSession
     * 
     * @param sessionId
     */
    public DaapSession(SessionId sessionId) {
        this.sessionId = sessionId;
        this.valid = true;
        this.lastAccesedTime = creationTime;
        this.maxInactiveTime = 1800;
    }

    /**
     * Returns the unique session id
     * 
     * @return the sessionId of this DaapSession
     */
    public SessionId getSessionId() {
        return sessionId;
    }

    /**
     * Returns the time when this session was accessed last time.
     * <p>
     * NOTE: currently unused!
     * </p>
     * 
     * @return
     */
    public synchronized long getLastAccessedTime() {
        return lastAccesedTime;
    }

    /**
     * Returns the creation time of this Session.
     * 
     * @return creation time
     */
    public long getCreationTime() {
        return creationTime;
    }

    /**
     * Returns the maximum inactive time.
     * <p>
     * NOTE: currently unused!
     * </p>
     * 
     * @return maximum inactive time
     */
    public synchronized int getMaxInactiveTime() {
        return maxInactiveTime;
    }

    /**
     * Sets the maximum inactive time.
     * <p>
     * NOTE: currently unused!
     * </p>
     * 
     * @param maxInactiveTime
     *            the maximum inactive time
     */
    public synchronized void setMaxInactiveTime(int maxInactiveTime) {
        this.maxInactiveTime = maxInactiveTime;
    }

    /**
     * Retruns <code>true</code> if this session object is valid and
     * <code>false</code> otherwise.
     * 
     * @return <code>true</code> if sesssion is valid
     */
    public synchronized boolean isValid() {
        return valid;
    }

    /**
     * Invalidates this session object
     */
    public synchronized void invalidate() {
        valid = false;
        attributes.clear();
    }

    /**
     * Returns an object that is associated with the key or <code>null</code> if
     * nothing is associated with the key
     * 
     * @param key
     *            a key
     * @return an object that is associated with the key or <code>null</code>
     */
    public synchronized Object getAttribute(String key) {
        return attributes.get(key);
    }

    /**
     * Attachs key/object to this Session
     * 
     * @param key
     *            a key
     * @param value
     *            an arbitrary object
     * @return <code>null</code> or the previous object that was associated with
     *         the key
     */
    public synchronized Object setAttribute(String key, Object value) {
        return attributes.put(key, value);
    }

    /**
     * Removes and returns an attribute that is associated with the key or
     * <code>null</code> if key is unknown.
     * 
     * @param key
     *            a key
     * @return the associated object or <code>null</code>
     */
    public synchronized Object removeAttribute(String key) {
        return attributes.remove(key);
    }

    /**
     * Returns an Iterator of all keys
     * 
     * @return an Iterator
     */
    public synchronized Iterator<String> getAttributeNames() {
        return attributes.keySet().iterator();
    }

    /**
     * Returs <code>true</code> if this Session object has a attribute
     * associated with the key
     * 
     * @param key
     *            a key
     * @return <code>true</code> if this Session has a such attribute
     */
    public synchronized boolean hasAttribute(String key) {
        return attributes.containsKey(key);
    }

    /**
     * Sets lastAccesedTime to 'now'
     * 
     */
    synchronized void update() {
        lastAccesedTime = System.currentTimeMillis();
    }

    @Override
    public String toString() {
        StringBuffer buffer = new StringBuffer();

        buffer.append("class: ").append(getClass().getName()).append("\n");
        buffer.append(" sessionId: ").append(sessionId).append("\n");
        buffer.append(" maxInactiveTime: ").append(maxInactiveTime)
                .append("\n");
        buffer.append(" creationTime: ").append(creationTime).append("\n");
        buffer.append(" lastAccesedTime: ").append(lastAccesedTime)
                .append("\n");
        buffer.append(" valid: ").append(valid).append("\n");
        buffer.append(" attributes: ").append(attributes).append("\n");

        return buffer.toString();
    }
}