java/jakarta/websocket/Session.java

/*
 * 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.websocket;

import java.io.Closeable;
import java.io.IOException;
import java.net.URI;
import java.security.Principal;
import java.util.List;
import java.util.Map;
import java.util.Set;

/**
 * Represents a WebSocket session, which is the WebSocket connection between a client and a server.
 * A session is created when a WebSocket connection is established and is used to send and receive
 * messages.
 */
public interface Session extends Closeable {

    /**
     * Get the container that created this session.
     *
     * @return the container that created this session.
     */
    WebSocketContainer getContainer();

    /**
     * Registers a {@link MessageHandler} for incoming messages. Only one {@link MessageHandler} may be registered for
     * each message type (text, binary, pong). The message type will be derived at runtime from the provided
     * {@link MessageHandler} instance. It is not always possible to do this so it is better to use
     * {@link #addMessageHandler(Class, jakarta.websocket.MessageHandler.Partial)} or
     * {@link #addMessageHandler(Class, jakarta.websocket.MessageHandler.Whole)}.
     *
     * @param handler The message handler for an incoming message
     *
     * @throws IllegalStateException If a message handler has already been registered for the associated message type
     */
    void addMessageHandler(MessageHandler handler) throws IllegalStateException;

    /**
     * Returns the set of message handlers currently registered on this session.
     *
     * @return The set of registered message handlers
     */
    Set<MessageHandler> getMessageHandlers();

    /**
     * Removes the specified message handler from this session.
     *
     * @param listener The message handler to remove
     */
    void removeMessageHandler(MessageHandler listener);

    /**
     * Returns the version of the WebSocket protocol in use for this session.
     *
     * @return The protocol version
     */
    String getProtocolVersion();

    /**
     * Returns the sub-protocol negotiated for this session, or {@code null} if no sub-protocol
     * was negotiated.
     *
     * @return The negotiated sub-protocol
     */
    String getNegotiatedSubprotocol();

    /**
     * Returns the list of extensions negotiated for this session.
     *
     * @return The list of negotiated extensions
     */
    List<Extension> getNegotiatedExtensions();

    /**
     * Returns whether this session is using a secure connection (wss://).
     *
     * @return {@code true} if the connection is secure
     */
    boolean isSecure();

    /**
     * Returns whether this session is currently open.
     *
     * @return {@code true} if the session is open
     */
    boolean isOpen();

    /**
     * Get the idle timeout for this session.
     *
     * @return The current idle timeout for this session in milliseconds. Zero or negative values indicate an infinite
     *             timeout.
     */
    long getMaxIdleTimeout();

    /**
     * Set the idle timeout for this session.
     *
     * @param timeout The new idle timeout for this session in milliseconds. Zero or negative values indicate an
     *                    infinite timeout.
     */
    void setMaxIdleTimeout(long timeout);

    /**
     * Set the current maximum buffer size for binary messages.
     *
     * @param max The new maximum buffer size in bytes
     */
    void setMaxBinaryMessageBufferSize(int max);

    /**
     * Get the current maximum buffer size for binary messages.
     *
     * @return The current maximum buffer size in bytes
     */
    int getMaxBinaryMessageBufferSize();

    /**
     * Set the maximum buffer size for text messages.
     *
     * @param max The new maximum buffer size in characters.
     */
    void setMaxTextMessageBufferSize(int max);

    /**
     * Get the maximum buffer size for text messages.
     *
     * @return The maximum buffer size in characters.
     */
    int getMaxTextMessageBufferSize();

    /**
     * Returns the asynchronous remote endpoint for this session, used for non-blocking message
     * sending.
     *
     * @return The asynchronous remote endpoint
     */
    RemoteEndpoint.Async getAsyncRemote();

    /**
     * Returns the synchronous remote endpoint for this session, used for blocking message sending.
     *
     * @return The synchronous remote endpoint
     */
    RemoteEndpoint.Basic getBasicRemote();

    /**
     * Provides a unique identifier for the session. This identifier should not be relied upon to be generated from a
     * secure random source.
     *
     * @return A unique identifier for the session.
     */
    String getId();

    /**
     * Close the connection to the remote end point using the code
     * {@link jakarta.websocket.CloseReason.CloseCodes#NORMAL_CLOSURE} and an empty reason phrase.
     *
     * @throws IOException if an I/O error occurs while the WebSocket session is being closed.
     */
    @Override
    void close() throws IOException;


    /**
     * Close the connection to the remote end point using the specified code and reason phrase.
     *
     * @param closeReason The reason the WebSocket session is being closed.
     *
     * @throws IOException if an I/O error occurs while the WebSocket session is being closed.
     */
    void close(CloseReason closeReason) throws IOException;

    /**
     * Returns the URI of the request that initiated this WebSocket session.
     *
     * @return The request URI
     */
    URI getRequestURI();

    /**
     * Returns the query parameters from the request that initiated this WebSocket session.
     *
     * @return The query parameter map
     */
    Map<String,List<String>> getRequestParameterMap();

    /**
     * Returns the query string from the request that initiated this WebSocket session.
     *
     * @return The query string
     */
    String getQueryString();

    /**
     * Returns the path parameters extracted from the request URI using the endpoint's URI template.
     *
     * @return The path parameter map
     */
    Map<String,String> getPathParameters();

    /**
     * Returns a map of user properties associated with this session.
     *
     * @return The user properties map
     */
    Map<String,Object> getUserProperties();

    /**
     * Returns the principal of the user associated with this session, or {@code null} if the
     * user is not authenticated.
     *
     * @return The user principal
     */
    Principal getUserPrincipal();

    /**
     * Obtain the set of open sessions associated with the same local endpoint as this session.
     *
     * @return The set of currently open sessions for the local endpoint that this session is associated with.
     */
    Set<Session> getOpenSessions();

    /**
     * Registers a {@link MessageHandler} for partial incoming messages. Only one {@link MessageHandler} may be
     * registered for each message type (text or binary, pong messages are never presented as partial messages).
     *
     * @param <T>     The type of message that the given handler is intended for
     * @param clazz   The Class that implements T
     * @param handler The message handler for an incoming message
     *
     * @throws IllegalStateException If a message handler has already been registered for the associated message type
     *
     * @since WebSocket 1.1
     */
    <T> void addMessageHandler(Class<T> clazz, MessageHandler.Partial<T> handler) throws IllegalStateException;

    /**
     * Registers a {@link MessageHandler} for whole incoming messages. Only one {@link MessageHandler} may be registered
     * for each message type (text, binary, pong).
     *
     * @param <T>     The type of message that the given handler is intended for
     * @param clazz   The Class that implements T
     * @param handler The message handler for an incoming message
     *
     * @throws IllegalStateException If a message handler has already been registered for the associated message type
     *
     * @since WebSocket 1.1
     */
    <T> void addMessageHandler(Class<T> clazz, MessageHandler.Whole<T> handler) throws IllegalStateException;
}