org.apache.jserv
Class JServSession

java.lang.Object
  |
  +--org.apache.jserv.JServSession
public class JServSession
extends java.lang.Object
implements javax.servlet.http.HttpSession, JServLogChannels, java.io.Serializable

This is the object that encapsulates a session.

Version:
$Revision: 1.15 $ $Date: 2000/05/24 22:41:28 $
See Also:
Serialized Form

Field Summary
private  JServServletManager context
          The session context
protected  long creationTime
          The time at which this session has been created
protected  java.lang.String id
          The session id
private  boolean isNew
          Is this session new
protected  long lastAccessTime
          The last time the session was accessed.
private  java.util.Hashtable sessionData
          The session data
private  boolean valid
          Is this session valid
 
Constructor Summary
JServSession(java.lang.String id, JServServletManager context)
          Creates a new session.
 
Method Summary
 void access()
          Tells the session that it has been accessed
private  void checkState()
          Throws an IllegalStateException when the session is no longer valid.
 long getCreationTime()
          Returns the time at which this session representation was created, in milliseconds since midnight, January 1, 1970 UTC.
 java.lang.String getId()
          Returns the identifier assigned to this session.
 long getLastAccessedTime()
          Returns the last time the client sent a request carrying the identifier assigned to the session.
 javax.servlet.http.HttpSessionContext getSessionContext()
          Returns the context in which this session is bound.
 java.lang.Object getValue(java.lang.String name)
          Returns the object bound to the given name in the session's application layer data.
 java.lang.String[] getValueNames()
          Returns an array of the names of all the application layer data objects bound into the session.
 void invalidate()
          Causes this representation of the session to be invalidated and removed from its context.
 boolean isNew()
          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.
 boolean isValid()
          Has the session been invalidated.
private  void log(java.lang.String channel, java.lang.String msg, java.lang.Throwable t)
          Logs an exception report to the servlet log file.
 void putValue(java.lang.String name, java.lang.Object value)
          Binds the specified object into the session's application layer data with the given name.
private  void readObject(java.io.ObjectInputStream stream)
          Read the instance variables for this object from the specified object input stream.
 void removeValue(java.lang.String name)
          Removes the object bound to the given name in the session's application layer data.
(package private)  void setSessionContext(JServServletManager context)
          Sets the context in which this session is bound.
private  void writeObject(java.io.ObjectOutputStream stream)
          Write the instance variables for this object to the specified object output stream.
 
Methods inherited from class java.lang.Object
, clone, equals, finalize, getClass, hashCode, notify, notifyAll, registerNatives, toString, wait, wait, wait
 

Field Detail

id

protected java.lang.String id
The session id

creationTime

protected long creationTime
The time at which this session has been created

lastAccessTime

protected long lastAccessTime
The last time the session was accessed.

sessionData

private java.util.Hashtable sessionData
The session data

context

private JServServletManager context
The session context

valid

private boolean valid
Is this session valid

isNew

private boolean isNew
Is this session new
Constructor Detail

JServSession

public JServSession(java.lang.String id,
                    JServServletManager context)
Creates a new session.
Parameters:
id - The id of the session.
context - The context of the session.
Method Detail

getId

public java.lang.String getId()
Returns the identifier assigned to this session. An HttpSession's identifier is a unique string that is created and maintained by HttpSessionContext.
Specified by:
getId in interface javax.servlet.http.HttpSession
Returns:
the identifier assigned to this session
Throws:
IllegalStateException - if an attempt is made to access session data after the session has been invalidated

getSessionContext

public javax.servlet.http.HttpSessionContext getSessionContext()
Returns the context in which this session is bound.
Specified by:
getSessionContext in interface javax.servlet.http.HttpSession
Returns:
the name of the context in which this session is bound
Throws:
IllegalStateException - if an attempt is made to access session data after the session has been invalidated

setSessionContext

void setSessionContext(JServServletManager context)
Sets the context in which this session is bound.

This is used by JServServletManager.init() to restore the contexts to the sessions after they have been serialized out.

getCreationTime

public long getCreationTime()
Returns the time at which this session representation was created, in milliseconds since midnight, January 1, 1970 UTC.
Specified by:
getCreationTime in interface javax.servlet.http.HttpSession
Returns:
the time when the session was created.
Throws:
IllegalStateException - if an attempt is made to access session data after the session has been invalidated

getLastAccessedTime

public long getLastAccessedTime()
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.

This information is particularly useful in session management policies. For example,

Specified by:
getLastAccessedTime in interface javax.servlet.http.HttpSession
Returns:
the last time the client sent a request carrying the identifier assigned to the session.
Throws:
IllegalStateException - if an attempt is made to access session data after the session has been invalidated

invalidate

public void invalidate()
Causes this representation of the session to be invalidated and removed from its context.
Specified by:
invalidate in interface javax.servlet.http.HttpSession
Throws:
IllegalStateException - if an attempt is made to access session data after the session has been invalidated

putValue

public void putValue(java.lang.String name,
                     java.lang.Object value)
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.
Specified by:
putValue in interface javax.servlet.http.HttpSession
Parameters:
name - the name to which the data object will be bound. This parameter cannot be null.
value - the data object to be bound. This parameter cannot be null.
Throws:
IllegalStateException - if an attempt is made to access session data after the session has been invalidated

getValue

public java.lang.Object getValue(java.lang.String name)
Returns the object bound to the given name in the session's application layer data. Returns null if there is no such binding.
Specified by:
getValue in interface javax.servlet.http.HttpSession
Parameters:
name - the name of the binding to find
Returns:
the value bound to that name, or null if the binding does not exist.
Throws:
IllegalStateException - if an attempt is made to access session data after the session has been invalidated

removeValue

public void removeValue(java.lang.String 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.
Specified by:
removeValue in interface javax.servlet.http.HttpSession
Parameters:
name - the name of the object to remove
Throws:
IllegalStateException - if an attempt is made to access session data after the session has been invalidated

getValueNames

public java.lang.String[] getValueNames()
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.
Specified by:
getValueNames in interface javax.servlet.http.HttpSession
Returns:
an array containing the names of all of the application layer data objects bound into the session
Throws:
IllegalStateException - if an attempt is made to access session data after the session has been invalidated

isNew

public boolean isNew()
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.
Specified by:
isNew in interface javax.servlet.http.HttpSession
Returns:
true if the session has been created by the server but the client has not yet acknowledged joining the session; false otherwise

isValid

public boolean isValid()
Has the session been invalidated.

access

public void access()
Tells the session that it has been accessed

checkState

private void checkState()
Throws an IllegalStateException when the session is no longer valid.

log

private void log(java.lang.String channel,
                 java.lang.String msg,
                 java.lang.Throwable t)
Logs an exception report to the servlet log file.
Parameters:
msg - The message to be written
t - The exception to be written

readObject

private void readObject(java.io.ObjectInputStream stream)
                 throws java.lang.ClassNotFoundException,
                        java.io.IOException
Read the instance variables for this object from the specified object input stream.
Parameters:
stream - The stream from which to read
Throws:
java.lang.ClassNotFoundException - if a required class cannot be found while deserializing
java.io.IOException - if an input error occurs while reading

writeObject

private void writeObject(java.io.ObjectOutputStream stream)
                  throws java.io.IOException
Write the instance variables for this object to the specified object output stream.
Parameters:
stream - The stream on which to write
Throws:
java.io.IOException - if an output error occurs while writing