org.springframework.web.server.WebSession Maven / Gradle / Ivy
/*
* Copyright 2002-2018 the original author or authors.
*
* 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.springframework.web.server;
import java.time.Duration;
import java.time.Instant;
import java.util.Map;
import reactor.core.publisher.Mono;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
/**
* Main contract for using a server-side session that provides access to session
* attributes across HTTP requests.
*
* The creation of a {@code WebSession} instance does not automatically start
* a session thus causing the session id to be sent to the client (typically via
* a cookie). A session starts implicitly when session attributes are added.
* A session may also be created explicitly via {@link #start()}.
*
* @author Rossen Stoyanchev
* @since 5.0
*/
public interface WebSession {
/**
* Return a unique session identifier.
*/
String getId();
/**
* Return a map that holds session attributes.
*/
Map getAttributes();
/**
* Return the session attribute value if present.
* @param name the attribute name
* @param the attribute type
* @return the attribute value
*/
@SuppressWarnings("unchecked")
@Nullable
default T getAttribute(String name) {
return (T) getAttributes().get(name);
}
/**
* Return the session attribute value or if not present raise an
* {@link IllegalArgumentException}.
* @param name the attribute name
* @param the attribute type
* @return the attribute value
*/
@SuppressWarnings("unchecked")
default T getRequiredAttribute(String name) {
T value = getAttribute(name);
Assert.notNull(value, () -> "Required attribute '" + name + "' is missing.");
return value;
}
/**
* Return the session attribute value, or a default, fallback value.
* @param name the attribute name
* @param defaultValue a default value to return instead
* @param the attribute type
* @return the attribute value
*/
@SuppressWarnings("unchecked")
default T getAttributeOrDefault(String name, T defaultValue) {
return (T) getAttributes().getOrDefault(name, defaultValue);
}
/**
* Force the creation of a session causing the session id to be sent when
* {@link #save()} is called.
*/
void start();
/**
* Whether a session with the client has been started explicitly via
* {@link #start()} or implicitly by adding session attributes.
* If "false" then the session id is not sent to the client and the
* {@link #save()} method is essentially a no-op.
*/
boolean isStarted();
/**
* Generate a new id for the session and update the underlying session
* storage to reflect the new id. After a successful call {@link #getId()}
* reflects the new session id.
* @return completion notification (success or error)
*/
Mono changeSessionId();
/**
* Invalidate the current session and clear session storage.
* @return completion notification (success or error)
*/
Mono invalidate();
/**
* Save the session through the {@code WebSessionStore} as follows:
*
* - If the session is new (i.e. created but never persisted), it must have
* been started explicitly via {@link #start()} or implicitly by adding
* attributes, or otherwise this method should have no effect.
*
- If the session was retrieved through the {@code WebSessionStore},
* the implementation for this method must check whether the session was
* {@link #invalidate() invalidated} and if so return an error.
*
* Note that this method is not intended for direct use by applications.
* Instead it is automatically invoked just before the response is
* committed.
* @return {@code Mono} to indicate completion with success or error
*/
Mono save();
/**
* Return {@code true} if the session expired after {@link #getMaxIdleTime()
* maxIdleTime} elapsed.
* Typically expiration checks should be automatically made when a session
* is accessed, a new {@code WebSession} instance created if necessary, at
* the start of request processing so that applications don't have to worry
* about expired session by default.
*/
boolean isExpired();
/**
* Return the time when the session was created.
*/
Instant getCreationTime();
/**
* Return the last time of session access as a result of user activity such
* as an HTTP request. Together with {@link #getMaxIdleTime()
* maxIdleTimeInSeconds} this helps to determine when a session is
* {@link #isExpired() expired}.
*/
Instant getLastAccessTime();
/**
* Configure the max amount of time that may elapse after the
* {@link #getLastAccessTime() lastAccessTime} before a session is considered
* expired. A negative value indicates the session should not expire.
*/
void setMaxIdleTime(Duration maxIdleTime);
/**
* Return the maximum time after the {@link #getLastAccessTime()
* lastAccessTime} before a session expires. A negative time indicates the
* session doesn't expire.
*/
Duration getMaxIdleTime();
}