/*
* Copyright 2002-2014 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.socket.sockjs.client;
import java.io.IOException;
import java.net.URI;
import java.security.Principal;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.http.HttpHeaders;
import org.springframework.util.Assert;
import org.springframework.util.concurrent.SettableListenableFuture;
import org.springframework.web.socket.CloseStatus;
import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.WebSocketMessage;
import org.springframework.web.socket.WebSocketSession;
import org.springframework.web.socket.sockjs.frame.SockJsFrame;
import org.springframework.web.socket.sockjs.frame.SockJsFrameType;
import org.springframework.web.socket.sockjs.frame.SockJsMessageCodec;
/**
* Base class for SockJS client implementations of {@link WebSocketSession}.
* Provides processing of incoming SockJS message frames and delegates lifecycle
* events and messages to the (application) {@link WebSocketHandler}.
* Sub-classes implement actual send as well as disconnect logic.
*
* @author Rossen Stoyanchev
* @since 4.1
*/
public abstract class AbstractClientSockJsSession implements WebSocketSession {
protected final Log logger = LogFactory.getLog(getClass());
private final TransportRequest request;
private final WebSocketHandler webSocketHandler;
private final SettableListenableFuture<WebSocketSession> connectFuture;
private final Map<String, Object> attributes = new ConcurrentHashMap<String, Object>();
private volatile State state = State.NEW;
private volatile CloseStatus closeStatus;
protected AbstractClientSockJsSession(TransportRequest request, WebSocketHandler handler,
SettableListenableFuture<WebSocketSession> connectFuture) {
Assert.notNull(request, "'request' is required");
Assert.notNull(handler, "'handler' is required");
Assert.notNull(connectFuture, "'connectFuture' is required");
this.request = request;
this.webSocketHandler = handler;
this.connectFuture = connectFuture;
}
@Override
public String getId() {
return this.request.getSockJsUrlInfo().getSessionId();
}
@Override
public URI getUri() {
return this.request.getSockJsUrlInfo().getSockJsUrl();
}
@Override
public HttpHeaders getHandshakeHeaders() {
return this.request.getHandshakeHeaders();
}
@Override
public Map<String, Object> getAttributes() {
return this.attributes;
}
@Override
public Principal getPrincipal() {
return this.request.getUser();
}
public SockJsMessageCodec getMessageCodec() {
return this.request.getMessageCodec();
}
public WebSocketHandler getWebSocketHandler() {
return this.webSocketHandler;
}
/**
* Return a timeout cleanup task to invoke if the SockJS sessions is not
* fully established within the retransmission timeout period calculated in
* {@code SockJsRequest} based on the duration of the initial SockJS "Info"
* request.
*/
Runnable getTimeoutTask() {
return new Runnable() {
@Override
public void run() {
closeInternal(new CloseStatus(2007, "Transport timed out"));
}
};
}
@Override
public boolean isOpen() {
return State.OPEN.equals(this.state);
}
public boolean isDisconnected() {
return (State.CLOSING.equals(this.state) || State.CLOSED.equals(this.state));
}
@Override
public final void sendMessage(WebSocketMessage<?> message) throws IOException {
Assert.state(State.OPEN.equals(this.state), this + " is not open, current state=" + this.state);
Assert.isInstanceOf(TextMessage.class, message, this + " supports text messages only.");
String payload = ((TextMessage) message).getPayload();
payload = getMessageCodec().encode(new String[] { payload });
payload = payload.substring(1); // the client-side doesn't need message framing (letter "a")
message = new TextMessage(payload);
if (logger.isTraceEnabled()) {
logger.trace("Sending message " + message + " in " + this);
}
sendInternal((TextMessage) message);
}
protected abstract void sendInternal(TextMessage textMessage) throws IOException;
@Override
public final void close() throws IOException {
close(CloseStatus.NORMAL);
}
@Override
public final void close(CloseStatus status) {
Assert.isTrue(status != null && isUserSetStatus(status), "Invalid close status: " + status);
if (logger.isDebugEnabled()) {
logger.debug("Closing session with " + status + " in " + this);
}
closeInternal(status);
}
private boolean isUserSetStatus(CloseStatus status) {
return (status.getCode() == 1000 || (status.getCode() >= 3000 && status.getCode() <= 4999));
}
protected void closeInternal(CloseStatus status) {
if (this.state == null) {
logger.warn("Ignoring close since connect() was never invoked");
return;
}
if (State.CLOSING.equals(this.state) || State.CLOSED.equals(this.state)) {
logger.debug("Ignoring close (already closing or closed), current state=" + this.state);
return;
}
this.state = State.CLOSING;
this.closeStatus = status;
try {
disconnect(status);
}
catch (Throwable ex) {
if (logger.isErrorEnabled()) {
logger.error("Failed to close " + this, ex);
}
}
}
protected abstract void disconnect(CloseStatus status) throws IOException;
public void handleFrame(String payload) {
SockJsFrame frame = new SockJsFrame(payload);
if (SockJsFrameType.OPEN.equals(frame.getType())) {
handleOpenFrame();
}
else if (SockJsFrameType.MESSAGE.equals(frame.getType())) {
handleMessageFrame(frame);
}
else if (SockJsFrameType.CLOSE.equals(frame.getType())) {
handleCloseFrame(frame);
}
else if (SockJsFrameType.HEARTBEAT.equals(frame.getType())) {
if (logger.isTraceEnabled()) {
logger.trace("Received heartbeat in " + this);
}
}
else {
// should never happen
throw new IllegalStateException("Unknown SockJS frame type " + frame + " in " + this);
}
}
private void handleOpenFrame() {
if (logger.isDebugEnabled()) {
logger.debug("Processing SockJS open frame in " + this);
}
if (State.NEW.equals(state)) {
this.state = State.OPEN;
try {
this.webSocketHandler.afterConnectionEstablished(this);
this.connectFuture.set(this);
}
catch (Throwable ex) {
if (logger.isErrorEnabled()) {
Class<?> type = this.webSocketHandler.getClass();
logger.error(type + ".afterConnectionEstablished threw exception in " + this, ex);
}
}
}
else {
if (logger.isDebugEnabled()) {
logger.debug("Open frame received in " + getId() + " but we're not" +
"connecting (current state=" + this.state + "). The server might " +
"have been restarted and lost track of the session.");
}
closeInternal(new CloseStatus(1006, "Server lost session"));
}
}
private void handleMessageFrame(SockJsFrame frame) {
if (!isOpen()) {
if (logger.isErrorEnabled()) {
logger.error("Ignoring received message due to state=" + this.state + " in " + this);
}
return;
}
String[] messages;
try {
messages = getMessageCodec().decode(frame.getFrameData());
}
catch (IOException ex) {
if (logger.isErrorEnabled()) {
logger.error("Failed to decode data for SockJS \"message\" frame: " + frame + " in " + this, ex);
}
closeInternal(CloseStatus.BAD_DATA);
return;
}
if (logger.isTraceEnabled()) {
logger.trace("Processing SockJS message frame " + frame.getContent() + " in " + this);
}
for (String message : messages) {
try {
if (isOpen()) {
this.webSocketHandler.handleMessage(this, new TextMessage(message));
}
}
catch (Throwable ex) {
Class<?> type = this.webSocketHandler.getClass();
logger.error(type + ".handleMessage threw an exception on " + frame + " in " + this, ex);
}
}
}
private void handleCloseFrame(SockJsFrame frame) {
CloseStatus closeStatus = CloseStatus.NO_STATUS_CODE;
try {
String[] data = getMessageCodec().decode(frame.getFrameData());
if (data.length == 2) {
closeStatus = new CloseStatus(Integer.valueOf(data[0]), data[1]);
}
if (logger.isDebugEnabled()) {
logger.debug("Processing SockJS close frame with " + closeStatus + " in " + this);
}
}
catch (IOException ex) {
if (logger.isErrorEnabled()) {
logger.error("Failed to decode data for " + frame + " in " + this, ex);
}
}
closeInternal(closeStatus);
}
public void handleTransportError(Throwable error) {
try {
if (logger.isErrorEnabled()) {
logger.error("Transport error in " + this, error);
}
this.webSocketHandler.handleTransportError(this, error);
}
catch (Exception ex) {
Class<?> type = this.webSocketHandler.getClass();
if (logger.isErrorEnabled()) {
logger.error(type + ".handleTransportError threw an exception", ex);
}
}
}
public void afterTransportClosed(CloseStatus closeStatus) {
this.closeStatus = (this.closeStatus != null ? this.closeStatus : closeStatus);
Assert.state(this.closeStatus != null, "CloseStatus not available");
if (logger.isDebugEnabled()) {
logger.debug("Transport closed with " + this.closeStatus + " in " + this);
}
this.state = State.CLOSED;
try {
this.webSocketHandler.afterConnectionClosed(this, this.closeStatus);
}
catch (Exception ex) {
if (logger.isErrorEnabled()) {
Class<?> type = this.webSocketHandler.getClass();
logger.error(type + ".afterConnectionClosed threw an exception", ex);
}
}
}
@Override
public String toString() {
return getClass().getSimpleName() + "[id='" + getId() + ", url=" + getUri() + "]";
}
private enum State { NEW, OPEN, CLOSING, CLOSED }
}