Java tutorial
/* * 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 * * https://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.socket.adapter.standard; import java.io.IOException; import java.net.InetSocketAddress; import java.net.URI; import java.security.Principal; import java.util.ArrayList; import java.util.Collections; import java.util.List; import java.util.Map; import javax.websocket.CloseReason; import javax.websocket.CloseReason.CloseCodes; import javax.websocket.Extension; import javax.websocket.Session; import org.springframework.http.HttpHeaders; import org.springframework.lang.Nullable; import org.springframework.util.Assert; import org.springframework.util.CollectionUtils; import org.springframework.web.socket.BinaryMessage; import org.springframework.web.socket.CloseStatus; import org.springframework.web.socket.PingMessage; import org.springframework.web.socket.PongMessage; import org.springframework.web.socket.TextMessage; import org.springframework.web.socket.WebSocketExtension; import org.springframework.web.socket.WebSocketSession; import org.springframework.web.socket.adapter.AbstractWebSocketSession; /** * A {@link WebSocketSession} for use with the standard WebSocket for Java API. * * @author Rossen Stoyanchev * @since 4.0 */ public class StandardWebSocketSession extends AbstractWebSocketSession<Session> { private final String id; @Nullable private URI uri; private final HttpHeaders handshakeHeaders; @Nullable private String acceptedProtocol; @Nullable private List<WebSocketExtension> extensions; @Nullable private Principal user; @Nullable private final InetSocketAddress localAddress; @Nullable private final InetSocketAddress remoteAddress; /** * Constructor for a standard WebSocket session. * @param headers the headers of the handshake request * @param attributes attributes from the HTTP handshake to associate with the WebSocket * session; the provided attributes are copied, the original map is not used. * @param localAddress the address on which the request was received * @param remoteAddress the address of the remote client */ public StandardWebSocketSession(@Nullable HttpHeaders headers, @Nullable Map<String, Object> attributes, @Nullable InetSocketAddress localAddress, @Nullable InetSocketAddress remoteAddress) { this(headers, attributes, localAddress, remoteAddress, null); } /** * Constructor that associates a user with the WebSocket session. * @param headers the headers of the handshake request * @param attributes attributes from the HTTP handshake to associate with the WebSocket session * @param localAddress the address on which the request was received * @param remoteAddress the address of the remote client * @param user the user associated with the session; if {@code null} we'll * fallback on the user available in the underlying WebSocket session */ public StandardWebSocketSession(@Nullable HttpHeaders headers, @Nullable Map<String, Object> attributes, @Nullable InetSocketAddress localAddress, @Nullable InetSocketAddress remoteAddress, @Nullable Principal user) { super(attributes); this.id = idGenerator.generateId().toString(); headers = (headers != null ? headers : new HttpHeaders()); this.handshakeHeaders = HttpHeaders.readOnlyHttpHeaders(headers); this.user = user; this.localAddress = localAddress; this.remoteAddress = remoteAddress; } @Override public String getId() { return this.id; } @Override @Nullable public URI getUri() { checkNativeSessionInitialized(); return this.uri; } @Override public HttpHeaders getHandshakeHeaders() { return this.handshakeHeaders; } @Override public String getAcceptedProtocol() { checkNativeSessionInitialized(); return this.acceptedProtocol; } @Override public List<WebSocketExtension> getExtensions() { Assert.state(this.extensions != null, "WebSocket session is not yet initialized"); return this.extensions; } public Principal getPrincipal() { return this.user; } @Override @Nullable public InetSocketAddress getLocalAddress() { return this.localAddress; } @Override @Nullable public InetSocketAddress getRemoteAddress() { return this.remoteAddress; } @Override public void setTextMessageSizeLimit(int messageSizeLimit) { checkNativeSessionInitialized(); getNativeSession().setMaxTextMessageBufferSize(messageSizeLimit); } @Override public int getTextMessageSizeLimit() { checkNativeSessionInitialized(); return getNativeSession().getMaxTextMessageBufferSize(); } @Override public void setBinaryMessageSizeLimit(int messageSizeLimit) { checkNativeSessionInitialized(); getNativeSession().setMaxBinaryMessageBufferSize(messageSizeLimit); } @Override public int getBinaryMessageSizeLimit() { checkNativeSessionInitialized(); return getNativeSession().getMaxBinaryMessageBufferSize(); } @Override public boolean isOpen() { return getNativeSession().isOpen(); } @Override public void initializeNativeSession(Session session) { super.initializeNativeSession(session); this.uri = session.getRequestURI(); this.acceptedProtocol = session.getNegotiatedSubprotocol(); List<Extension> standardExtensions = getNativeSession().getNegotiatedExtensions(); if (!CollectionUtils.isEmpty(standardExtensions)) { this.extensions = new ArrayList<>(standardExtensions.size()); for (Extension standardExtension : standardExtensions) { this.extensions.add(new StandardToWebSocketExtensionAdapter(standardExtension)); } this.extensions = Collections.unmodifiableList(this.extensions); } else { this.extensions = Collections.emptyList(); } if (this.user == null) { this.user = session.getUserPrincipal(); } } @Override protected void sendTextMessage(TextMessage message) throws IOException { getNativeSession().getBasicRemote().sendText(message.getPayload(), message.isLast()); } @Override protected void sendBinaryMessage(BinaryMessage message) throws IOException { getNativeSession().getBasicRemote().sendBinary(message.getPayload(), message.isLast()); } @Override protected void sendPingMessage(PingMessage message) throws IOException { getNativeSession().getBasicRemote().sendPing(message.getPayload()); } @Override protected void sendPongMessage(PongMessage message) throws IOException { getNativeSession().getBasicRemote().sendPong(message.getPayload()); } @Override protected void closeInternal(CloseStatus status) throws IOException { getNativeSession().close(new CloseReason(CloseCodes.getCloseCode(status.getCode()), status.getReason())); } }