org.apache.tomcat/tomcat-servlet-api/10.0.0 : jakarta/servlet/http/HttpSession.java

HttpSession
https://tomcat.apache.org/: jakarta.servlet package
Apache License, Version 2.0 and Common Development And Distribution License (CDDL) Version 1.0 and Eclipse Public License - v 2.0
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 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 jakarta.servlet.http;

import java.util.Enumeration;

import jakarta.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 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 invalidated or expired. 
 When container migrates a session between VMs in a distributed container setting, all session attributes implementing the 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 Also: HttpSessionBindingListener/**
 * 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.
 * <p>
 * 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.
 * <p>
 * This interface allows servlets to
 * <ul>
 * <li>View and manipulate information about a session, such as the session
 * identifier, creation time, and last accessed time
 * <li>Bind objects to sessions, allowing user information to persist across
 * multiple user connections
 * </ul>
 * <p>
 * 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 invalidated or
 * expired.
 * <p>
 * When container migrates a session between VMs in a distributed container
 * setting, all session attributes implementing the
 * {@link HttpSessionActivationListener} interface are notified.
 * <p>
 * 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, <code>isNew</code> returns <code>true</code>.
 * If the client chooses not to join the session, <code>getSession</code> will
 * return a different session on each request, and <code>isNew</code> will
 * always return <code>true</code>.
 * <p>
 * Session information is scoped only to the current web application (
 * <code>ServletContext</code>), so information stored in one context will not
 * be directly visible in another.
 *
 * @see HttpSessionBindingListener
 */
public interface HttpSession {

    Returns the time when this session was created, measured in milliseconds
since midnight January 1, 1970 GMT.
Throws: IllegalStateException – 
               if this method is called on an invalidated session
Returns: a long specifying when this session was created,
        expressed in milliseconds since 1/1/1970 GMT/**
     * Returns the time when this session was created, measured in milliseconds
     * since midnight January 1, 1970 GMT.
     *
     * @return a <code>long</code> 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.
Throws: IllegalStateException – 
               if this method is called on an invalidated session
Returns: a string specifying the identifier assigned to this session/**
     * 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.
Throws: IllegalStateException – 
               if this method is called on an invalidated session
Returns: a long representing the last time the client sent a
        request associated with this session, expressed in milliseconds
        since 1/1/1970 GMT/**
     * 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.
     * <p>
     * Actions that your application takes, such as getting or setting a value
     * associated with the session, do not affect the access time.
     *
     * @return a <code>long</code> 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.
Returns: The ServletContext object for the web application
Since: 2.3/**
     * Returns the ServletContext to which this session belongs.
     *
     * @return The ServletContext object for the web application
     * @since 2.3
     */
    public ServletContext getServletContext();

    Specifies the time, in seconds, between client requests before the
servlet container will invalidate this session. A zero or negative time
indicates that the session should never timeout.
Params: interval – 
           An integer specifying the number of seconds/**
     * Specifies the time, in seconds, between client requests before the
     * servlet container will invalidate this session. A zero or negative time
     * indicates that 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 zero or negative time indicates that the session should never timeout.
See Also: setMaxInactiveInterval
Returns: an integer specifying the number of seconds this session remains
        open between client requests/**
     * 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 <code>setMaxInactiveInterval</code> method.
     * A zero or negative time indicates that 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();

    Do not use.
Returns: A dummy implementation of HttpSessionContext
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./**
     * Do not use.
     * @return A dummy implementation of HttpSessionContext
     * @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.
     */
    @Deprecated
    public HttpSessionContext getSessionContext();

    Returns the object bound with the specified name in this session, or
null if no object is bound under the name.
Params: name – 
           a string specifying the name of the object
Throws: IllegalStateException – 
               if this method is called on an invalidated session
Returns: the object with the specified name/**
     * Returns the object bound with the specified name in this session, or
     * <code>null</code> 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);

    Params: name – 
           a string specifying the name of the object
Throws: IllegalStateException – 
               if this method is called on an invalidated session
Returns: the object with the specified name
Deprecated: As of Version 2.2, this method is replaced by 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
     * @deprecated As of Version 2.2, this method is replaced by
     *             {@link #getAttribute}.
     */
    @Deprecated
    public Object getValue(String name);

    Returns an Enumeration of String objects
containing the names of all the objects bound to this session.
Throws: IllegalStateException – 
               if this method is called on an invalidated session
Returns: an Enumeration of String objects
        specifying the names of all the objects bound to this session/**
     * Returns an <code>Enumeration</code> of <code>String</code> objects
     * containing the names of all the objects bound to this session.
     *
     * @return an <code>Enumeration</code> of <code>String</code> 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<String> getAttributeNames();

    Throws: IllegalStateException – 
               if this method is called on an invalidated session
Returns: an array of String objects specifying the names of
        all the objects bound to this session
Deprecated: As of Version 2.2, this method is replaced by getAttributeNames/**
     * @return an array of <code>String</code> objects specifying the names of
     *         all the objects bound to this session
     * @exception IllegalStateException
     *                if this method is called on an invalidated session
     * @deprecated As of Version 2.2, this method is replaced by
     *             {@link #getAttributeNames}
     */
    @Deprecated
    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().
Params: name – 
           the name to which the object is bound; cannot be null
value – 
           the object to be bound
Throws: IllegalStateException – 
               if this method is called on an invalidated session/**
     * 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.
     * <p>
     * After this method executes, and if the new object implements
     * <code>HttpSessionBindingListener</code>, the container calls
     * <code>HttpSessionBindingListener.valueBound</code>. The container then
     * notifies any <code>HttpSessionAttributeListener</code>s in the web
     * application.
     * <p>
     * If an object was already bound to this session of this name that
     * implements <code>HttpSessionBindingListener</code>, its
     * <code>HttpSessionBindingListener.valueUnbound</code> method is called.
     * <p>
     * If the value passed in is null, this has the same effect as calling
     * <code>removeAttribute()</code>.
     *
     * @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);

    Params: name – 
           the name to which the object is bound; cannot be null
value – 
           the object to be bound; cannot be null
Throws: IllegalStateException – 
               if this method is called on an invalidated session
Deprecated: As of Version 2.2, this method is replaced by 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
     * @deprecated As of Version 2.2, this method is replaced by
     *             {@link #setAttribute}
     */
    @Deprecated
    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.
Params: name – 
           the name of the object to remove from this session
Throws: IllegalStateException – 
               if this method is called on an invalidated session/**
     * 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.
     * <p>
     * After this method executes, and if the object implements
     * <code>HttpSessionBindingListener</code>, the container calls
     * <code>HttpSessionBindingListener.valueUnbound</code>. The container then
     * notifies any <code>HttpSessionAttributeListener</code>s 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);

    Params: name – 
           the name of the object to remove from this session
Throws: IllegalStateException – 
               if this method is called on an invalidated session
Deprecated: As of Version 2.2, this method is replaced by removeAttribute/**
     * @param name
     *            the name of the object to remove from this session
     * @exception IllegalStateException
     *                if this method is called on an invalidated session
     * @deprecated As of Version 2.2, this method is replaced by
     *             {@link #removeAttribute}
     */
    @Deprecated
    public void removeValue(String name);

    Invalidates this session then unbinds any objects bound to it.
Throws: IllegalStateException – 
               if this method is called on an already invalidated session/**
     * 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.
Throws: IllegalStateException – 
               if this method is called on an already invalidated session
Returns: true if the server has created a session, but the
        client has not yet joined/**
     * Returns <code>true</code> 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 <code>true</code> 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();
}
Throws:	IllegalStateException – if this method is called on an invalidated session
Returns:	a `long` specifying when this session was created, expressed in milliseconds since 1/1/1970 GMT
Returns:	The ServletContext object for the web application
Since:	2.3
See Also:	setMaxInactiveInterval
Returns:	an integer specifying the number of seconds this session remains open between client requests
Returns:	A dummy implementation of HttpSessionContext
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.
Params:	name – a string specifying the name of the object
Throws:	IllegalStateException – if this method is called on an invalidated session
Returns:	the object with the specified name
Params:	name – the name to which the object is bound; cannot be null value – the object to be bound
Throws:	IllegalStateException – if this method is called on an invalidated session
Params:	name – the name of the object to remove from this session
Throws:	IllegalStateException – if this method is called on an invalidated session
/

org.apache.tomcat/ tomcat-servlet-api/ 10.0.0/ jakarta/servlet/http/HttpSession.java
