javax.servlet.http.HttpSession Maven / Gradle / Ivy
/**
*
* Copyright 2003-2004 The Apache Software Foundation
*
* 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.
*/
//
// This source code implements specifications defined by the Java
// Community Process. In order to remain compliant with the specification
// DO NOT add / change / or delete method signatures!
//
package javax.servlet.http;
import java.util.Enumeration;
import javax.servlet.ServletContext;
/**
* Provides a way to identify a user across more than one page
* request or visit to a Web site and to store information about that user.
*
* The servlet container uses this interface to create a session
* between an HTTP client and an HTTP server. The session persists
* for a specified time period, across more than one connection or
* page request from the user. A session usually corresponds to one
* user, who may visit a site many times. The server can maintain a
* session in many ways such as using cookies or rewriting URLs.
*
*
This interface allows servlets to
*
* - View and manipulate information about a session, such as
* the session identifier, creation time, and last accessed time
*
- Bind objects to sessions, allowing user information to persist
* across multiple user connections
*
*
* When an application stores an object in or removes an object from a
* session, the session checks whether the object implements
* {@link HttpSessionBindingListener}. If it does,
* the servlet notifies the object that it has been bound to or unbound
* from the session. Notifications are sent after the binding methods complete.
* For session that are invalidated or expire, notifications are sent after
* the session has been invalidatd or expired.
*
*
When container migrates a session between VMs in a distributed container
* setting, all session attributes implementing the {@link HttpSessionActivationListener}
* interface are notified.
*
*
A servlet should be able to handle cases in which
* the client does not choose to join a session, such as when cookies are
* intentionally turned off. Until the client joins the session,
* isNew returns true. If the client chooses
* not to join
* the session, getSession will return a different session
* on each request, and isNew will always return
* true.
*
*
Session information is scoped only to the current web application
* (ServletContext), so information stored in one context
* will not be directly visible in another.
*
* @see HttpSessionBindingListener
* @see HttpSessionContext
*
* @version $Rev: 46019 $ $Date: 2004-09-14 04:56:06 -0500 (Tue, 14 Sep 2004) $
*/
public interface HttpSession {
/**
* Returns the time when this session was created, measured
* in milliseconds since midnight January 1, 1970 GMT.
*
* @return a long specifying when this session was created,
* expressed in milliseconds since 1/1/1970 GMT
*
* @exception IllegalStateException if this method is called on an
* invalidated session
*/
public long getCreationTime();
/**
* Returns a string containing the unique identifier assigned to this
* session. The identifier is assigned by the servlet container and is
* implementation dependent.
*
* @return a string specifying the identifier assigned to this session
*
* @exception IllegalStateException if this method is called on an
* invalidated session
*/
public String getId();
/**
* Returns the last time the client sent a request associated with
* this session, as the number of milliseconds since midnight
* January 1, 1970 GMT, and marked by the time the container received the request.
*
*
Actions that your application takes, such as getting or setting
* a value associated with the session, do not affect the access
* time.
*
* @return a long representing the last time the client sent
* a request associated with this session, expressed in milliseconds since
* 1/1/1970 GMT
*
* @exception IllegalStateException if this method is called on an
* invalidated session
*/
public long getLastAccessedTime();
/**
* Returns the ServletContext to which this session belongs.
*
* @return The ServletContext object for the web application
* @since Servlet 2.3
*/
public ServletContext getServletContext();
/**
* Specifies the time, in seconds, between client requests before the
* servlet container will invalidate this session. A negative time
* indicates the session should never timeout.
*
* @param interval An integer specifying the number of seconds
*/
public void setMaxInactiveInterval(int interval);
/**
* Returns the maximum time interval, in seconds, that
* the servlet container will keep this session open between
* client accesses. After this interval, the servlet container
* will invalidate the session. The maximum time interval can be set
* with the setMaxInactiveInterval method.
* A negative time indicates the session should never timeout.
*
* @return an integer specifying the number of seconds this session
* remains open between client requests
*
* @see #setMaxInactiveInterval
*/
public int getMaxInactiveInterval();
/**
* @deprecated As of Version 2.1, this method is deprecated and has no
* replacement. It will be removed in a future version of the Java Servlet
* API.
*/
public HttpSessionContext getSessionContext();
/**
* Returns the object bound with the specified name in this session, or
* null if no object is bound under the name.
*
* @param name a string specifying the name of the object
*
* @return the object with the specified name
*
* @exception IllegalStateException if this method is called on an
* invalidated session
*/
public Object getAttribute(String name);
/**
* @deprecated As of Version 2.2, this method is replaced by
* {@link #getAttribute}.
*
* @param name a string specifying the name of the object
*
* @return the object with the specified name
*
* @exception IllegalStateException if this method is called on an
* invalidated session
*/
public Object getValue(String name);
/**
* Returns an Enumeration of String objects
* containing the names of all the objects bound to this session.
*
* @return an Enumeration of String objects
* specifying the names of all the objects bound to this session
*
* @exception IllegalStateException if this method is called on an
* invalidated session
*/
public Enumeration getAttributeNames();
/**
* @deprecated As of Version 2.2, this method is replaced by
* {@link #getAttributeNames}
*
* @return an array of String objects specifying the names of
* all the objects bound to this session
*
* @exception IllegalStateException if this method is called on an
* invalidated session
*/
public String[] getValueNames();
/**
* Binds an object to this session, using the name specified. If an object
* of the same name is already bound to the session, the object is
* replaced.
*
*
After this method executes, and if the new object implements
* HttpSessionBindingListener, the container calls
* HttpSessionBindingListener.valueBound. The container then
* notifies any HttpSessionAttributeListeners in the web
* application.
*
*
If an object was already bound to this session of this name
* that implements HttpSessionBindingListener, its
* HttpSessionBindingListener.valueUnbound method is called.
*
*
If the value passed in is null, this has the same effect as calling
* removeAttribute().
*
* @param name the name to which the object is bound; cannot be null
*
* @param value the object to be bound
*
* @exception IllegalStateException if this method is called on an
* invalidated session
*/
public void setAttribute(String name, Object value);
/**
* @deprecated As of Version 2.2, this method is replaced by
* {@link #setAttribute}
*
* @param name the name to which the object is bound; cannot be null
*
* @param value the object to be bound; cannot be null
*
* @exception IllegalStateException if this method is called on an
* invalidated session
*/
public void putValue(String name, Object value);
/**
* Removes the object bound with the specified name from this session.
* If the session does not have an object bound with the specified name,
* this method does nothing.
*
* After this method executes, and if the object implements
* HttpSessionBindingListener, the container calls
* HttpSessionBindingListener.valueUnbound. The container
* then notifies any HttpSessionAttributeListeners in the web
* application.
*
* @param name the name of the object to remove from this session
*
* @exception IllegalStateException if this method is called on an
* invalidated session
*/
public void removeAttribute(String name);
/**
* @deprecated As of Version 2.2, this method is replaced by
* {@link #removeAttribute}
*
* @param name the name of the object to remove from this session
*
* @exception IllegalStateException if this method is called on an
* invalidated session
*/
public void removeValue(String name);
/**
* Invalidates this session then unbinds any objects bound to it.
*
* @exception IllegalStateException if this method is called on an already
* invalidated session
*/
public void invalidate();
/**
* Returns true if the client does not yet know about the
* session or if the client chooses not to join the session. For
* example, if the server used only cookie-based sessions, and
* the client had disabled the use of cookies, then a session would
* be new on each request.
*
* @return true if the server has created a session, but the
* client has not yet joined
*
* @exception IllegalStateException if this method is called on an already
* invalidated session
*/
public boolean isNew();
}