Australian Personal Computer 2000 November/APCD25112k.iso/feature/webserv/SAMBAR43.ZIP/_SETUP.1/javaeng.jar/com/sambar/javaeng/SambarSession.java

Java Source | 2000-04-03 | 7.0 KB | 252 lines

/*
**         Sambar Server JAVA Engine Session Implementation
**
**        Confidential Property of Tod Sambar
**        (c) Copyright Tod Sambar 1999
**        All rights reserved.
*/
package com.sambar.javaeng;

import java.util.*;
import javax.servlet.http.*;

public class SambarSession implements HttpSession
{
    protected long             creationTime;
    protected long             lastAccessTime;
    protected int            inactiveInterval;
    protected String         id;
    private boolean         isNew;
    private boolean         valid;
    private Hashtable         sessionData;
    private SambarContext     scontext;

    public SambarSession(String id, SambarContext scontext, int sessionTimeout)
    {
        this.valid = true;
        this.id = id;
        this.scontext = scontext;
        this.sessionData = new Hashtable();
        this.creationTime = System.currentTimeMillis();
        this.lastAccessTime = creationTime;
        this.isNew = true;
        this.inactiveInterval = sessionTimeout;
    }

    /*
    ** Returns the identifier assigned to this session. An HttpSession's
    ** identifier is a unique string that is created and maintained by
    ** HttpSessionContext.
    */
    public synchronized String getId()
    {
        checkState();
        return id;
    }

    public int getMaxInactiveInterval()
    {
        return inactiveInterval;
    }

    public void setMaxInactiveInterval(int inactiveInterval)
    {
        this.inactiveInterval = inactiveInterval;
    }

    /*
    ** Returns the context in which this session is bound.
    */
    public synchronized HttpSessionContext getSessionContext()
    {
        checkState();
        return scontext;
    }

    /*
    ** Returns the time at which this session representation was created,
    ** in milliseconds since midnight, January 1, 1970 UTC.
    */
    public synchronized long getCreationTime()
    {
        checkState();
        return creationTime;
    }

    /*
    ** Returns the last time the client sent a request carrying the identifier
    ** assigned to the session. Time is expressed
    ** as milliseconds since midnight, January 1,
    ** 1970 UTC.
    ** Application level operations, such as getting or setting a value
    ** associated with the session, does not affect the access time.
    */
    public synchronized long getLastAccessedTime()
    {
        checkState();
        return lastAccessTime;
    }

    /*
    ** Causes this representation of the session to be invalidated and removed
    ** from its context.
    */
    public synchronized void invalidate()
    {
        checkState();
        valid = false;

        // deliver HttpSessionBindingEvent to all values that want it
        Enumeration namesEnum;
        Object name, value;

        namesEnum = sessionData.keys();
        while (namesEnum.hasMoreElements())
        {
            name = namesEnum.nextElement();
            value = sessionData.get(name);
            if (value instanceof HttpSessionBindingListener)
            {
                HttpSessionBindingListener listener =
                    (HttpSessionBindingListener)value;
                listener.valueUnbound(new HttpSessionBindingEvent(this,
                    (String) name));
            }
        }

        scontext.removeSession(this);
    }

    /*
    ** Binds the specified object into the session's application layer data
    ** with the given name.  Any existing binding with the same name is
    ** replaced.  New (or existing) values that implement the
    ** HttpSessionBindingListener interface will call its
    ** valueBound() method.
    */
    public synchronized void putValue(String name, Object value)
    {
        checkState();
        removeValue(name);
        sessionData.put(name, value);
        if (value instanceof HttpSessionBindingListener)
        {
            HttpSessionBindingListener listener =
                (HttpSessionBindingListener)value;
            listener.valueBound(new HttpSessionBindingEvent(this, name));
        }
    }

    /*
    ** Returns the object bound to the given name in the session's
    ** application layer data.  Returns null if there is no such binding.
    */
    public synchronized Object getValue(String name)
    {
        checkState();
        return sessionData.get(name);
    }

    /*
    ** Removes the object bound to the given name in the session's
    ** application layer data.  Does nothing if there is no object
    ** bound to the given name.  The value that implements the
    ** HttpSessionBindingListener interface will call its
    ** valueUnbound() method.
    */
    public synchronized void removeValue(String name)
    {
        checkState();
        Object value = sessionData.remove(name);
        if (value instanceof HttpSessionBindingListener)
        {
            HttpSessionBindingListener listener =
                (HttpSessionBindingListener)value;
            listener.valueUnbound(new HttpSessionBindingEvent(this, name));
        }
    }

    /*
    ** Returns an array of the names of all the application layer
    ** data objects bound into the session. For example, if you want to delete
    ** all of the data objects bound into the session, use this method to
    ** obtain their names.
    */
    public synchronized String[] getValueNames()
    {
        checkState();
        Vector buf = new Vector();
        Enumeration namesEnum = sessionData.keys();
        while (namesEnum.hasMoreElements())
            buf.addElement(namesEnum.nextElement());

        String[] names = new String[buf.size()];
        buf.copyInto(names);
        return names;
    }

    /*
    ** A session is considered to be "new" if it has been created by the server,
    ** but the client has not yet acknowledged joining the session. For example,
    ** if the server supported only cookie-based sessions and the client had
    ** completely disabled the use of cookies, then calls to
    ** HttpServletRequest.getSession() would
    ** always return "new" sessions.
    */
    public synchronized boolean isNew()
    {
        checkState();
        return isNew;
    }

    /*
    ** Has the session been invalidated.
    */
    public boolean isValid()
    {
        return valid;
    }

    /*
    ** Tells the session that it has been accessed
    */
    public synchronized void access()
    {
        lastAccessTime = System.currentTimeMillis();
        isNew = false;
    }

    /*
    ** Throws an IllegalStateException when the session is no longer valid.
    */
    private void checkState()
    {
        if (!valid)
        {
            throw new IllegalStateException("Session " + id +
                " has been invalidated.");
        }
    }

    public Object getAttribute(String name)
    {
        return getValue(name);
    }

    public Enumeration getAttributeNames()
    {
        checkState();
        return sessionData.keys();
    }

    public void setAttribute(String name, Object object)
    {
        putValue(name, object);
    }

    public void removeAttribute(String name)
    {
        removeValue(name);
    }
}