最近项目中需要使用WebSocket实现实时传递消息功能，网上大多数都是 Socket 实现，而 使用Spring 的WebSocket 的也有不少，但是大多数都只写了一种方法：@ServerEndpoint() 这个方法 ，其实还有另一种方法 WebSocketConfigurer 。这里将会把两种方法介绍下。
@ServerEndpoint() 方法
服务端配置
- WebSocket 配置类
@Configuration
public class WebSocketConfig {
@Bean
public ServerEndpointExporter serverEndpointExporter(){
return new ServerEndpointExporter();
}
}
- 服务端类
@Component
@ServerEndpoint(value ="/websocket/server1")
public class WebSocketServer {
private Logger logger = LoggerFactory.getLogger(WebSocketServer.class);
@OnOpen
public void onOpen(Session session) {
logger.info("-----server open");
}
@OnMessage
public void onMessage(Session session, String message) throws IOException {
logger.info("-----server message:{}", message);
if ("ABC".equals(message)){
session.getBasicRemote().sendText("DEF");
}
}
@OnMessage
public void onBinaryMessage(ByteBuffer buffer, Session session){
logger.info("-----server binary message:{}", buffer);
}
@OnClose
public void onClose(Session session, CloseReason closeReason){
logger.info("-----server close");
}
@OnError
public void onError(Session session, Throwable throwable){
logger.error("-----server error", throwable);
}
}
客户端
public class WebSocketClient extends Endpoint {
private Logger logger = LoggerFactory.getLogger(WebSocketClient.class);
@Override
public void onClose(Session session, CloseReason closeReason) {
super.onClose(session, closeReason);
logger.info("-----client close");
}
@Override
public void onError(Session session, Throwable throwable) {
super.onError(session, throwable);
logger.error("-----client error", throwable);
}
@Override
public void onOpen(final Session session, EndpointConfig endpointConfig) {
logger.info("-----client open");
session.addMessageHandler(new MessageHandler.Whole<String>() {
public void onMessage(String s) {
logger.info("-----client message:{}", s);
try {
onHandleMessage(session, s);
} catch (IOException e) {
e.printStackTrace();
}
}
});
try {
session.getBasicRemote().sendText("ABC");
} catch (IOException e) {
e.printStackTrace();
}
}
private void onHandleMessage(Session session, String message) throws IOException {
if ("DEF".equals(message)){
session.close();
}
}
}
连接方法
WebSocketContainer container = ContainerProvider.getWebSocketContainer();
ClientEndpointConfig clientEndpointConfig = ClientEndpointConfig.Builder
.create().configurator(new ClientEndpointConfig.Configurator(){
@Override
public void beforeRequest(Map<String, List<String>> headers) {
super.beforeRequest(headers);
List<String> values = new ArrayList<String>();
values.add("v"); // header value
headers.put("k",values);// header
}
}).build();
Session session = container.connectToServer(WebSocketClient.class, clientEndpointConfig, URI.create("ws://localhost:8181/websocket/server1"));
- 要想忽略ssl认证，则需要添加SSLContext
SSLContext sslContext = SSLContext.getInstance("SSL");
sslContext.init(null, new X509ExtendedTrustManager[]{x509ExtendedTrustManager},new SecureRandom());
WebSocketContainer container = ContainerProvider.getWebSocketContainer();
ClientEndpointConfig clientEndpointConfig = ClientEndpointConfig.Builder
.create().configurator(new ClientEndpointConfig.Configurator(){
@Override
public void beforeRequest(Map<String, List<String>> headers) {
super.beforeRequest(headers);
List<String> values = new ArrayList<String>();
values.add("v");
headers.put("k",values);
}
}).build();
clientEndpointConfig.getUserProperties().put(SSL_CONTEXT_PROPERTY, sslContext);
x509ExtendedTrustManager 必须是
javax.net.ssl.X509ExtendedTrustManager下的包。
连接后Log 信息
2021-10-30 11:17:44.515 INFO 15808 --- [nio-8181-exec-1] c.e.websocket.spring1.WebSocketClient : -----client open
2021-10-30 11:17:44.518 INFO 15808 --- [nio-8181-exec-2] c.e.websocket.spring1.WebSocketServer : -----server open
2021-10-30 11:17:44.532 INFO 15808 --- [nio-8181-exec-3] c.e.websocket.spring1.WebSocketServer : -----server message:ABC
2021-10-30 11:17:44.537 INFO 15808 --- [lient-AsyncIO-1] c.e.websocket.spring1.WebSocketClient : -----client message:DEF
2021-10-30 11:17:44.538 INFO 15808 --- [lient-AsyncIO-1] c.e.websocket.spring1.WebSocketClient : -----client close
2021-10-30 11:17:44.538 INFO 15808 --- [nio-8181-exec-4] c.e.websocket.spring1.WebSocketServer : -----server close
WebSocketConfigurer 方法
服务端配置
- AbstractWebSocketHandler 实现，主要是接收消息
@Component
public class WebSocketServerHandler extends AbstractWebSocketHandler {
private Logger logger = LoggerFactory.getLogger(WebSocketServerHandler.class);
@Override
public void afterConnectionEstablished(WebSocketSession session) throws Exception {
super.afterConnectionEstablished(session);
logger.info("-----server open");
}
@Override
public void afterConnectionClosed(WebSocketSession session, CloseStatus status) throws Exception {
super.afterConnectionClosed(session, status);
logger.info("-----server close");
}
@Override
public void handleTransportError(WebSocketSession session, Throwable exception) throws Exception {
super.handleTransportError(session, exception);
logger.error("-----server error", exception);
}
@Override
protected void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception {
super.handleTextMessage(session, message);
logger.info("-----server text message:{}", message.getPayload());
if ("ABC".equals(message.getPayload())){
session.sendMessage(new TextMessage("DEF"));
}
}
@Override
protected void handleBinaryMessage(WebSocketSession session, BinaryMessage message) throws Exception {
super.handleBinaryMessage(session, message);
logger.info("-----server binary message:{}", message.getPayload());
}
@Override
protected void handlePongMessage(WebSocketSession session, PongMessage message) throws Exception {
super.handlePongMessage(session, message);
logger.info("-----server pong message:{}", message.getPayload());
}
@Override
public void handleMessage(WebSocketSession session, WebSocketMessage<?> message) throws Exception {
super.handleMessage(session, message);
logger.info("-----server message:{}", message.getPayload());
}
}
- HandshakeInterceptor 实现，主要作用是对请求的拦截
@Component
public class WebSocketServerInterceptor implements HandshakeInterceptor {
private Logger logger = LoggerFactory.getLogger(WebSocketServerInterceptor.class);
public boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler, Map<String, Object> attributes) {
logger.info("-----server beforeHandshake");
logger.info("-----server beforeHandshake request Headers :{}",request.getHeaders());
logger.info("-----server beforeHandshake: attributes{}",attributes);
return true; // 默认 false ，会报 DeploymentException: The HTTP response from the server [200] did not permit the HTTP upgrade to WebSocket 错误
}
public void afterHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler, Exception exception) {
logger.info("-----server afterHandshake");
}
}
- WebSocket 配置，主要是配置跨域、请求路径等
@EnableWebSocket
@Configuration
public class WebSocketServerConfig implements WebSocketConfigurer {
@Autowired
private WebSocketServerHandler webSocketServerHandler;
@Autowired
private WebSocketServerInterceptor webSocketServerInterceptor;
public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
registry.addHandler(webSocketServerHandler, "websocket/server2")
.addInterceptors(webSocketServerInterceptor)
.setAllowedOrigins("*");
}
}
客户端
- AbstractWebSocketHandler实现，主要作用是接收数据，连接监听等。
@Component
public class WebSocketClientHandler extends AbstractWebSocketHandler {
private Logger logger = LoggerFactory.getLogger(WebSocketClientHandler.class);
@Override
public void afterConnectionEstablished(WebSocketSession session) throws Exception {
super.afterConnectionEstablished(session);
logger.info("-----client open");
session.sendMessage(new TextMessage("ABC"));
}
@Override
public void afterConnectionClosed(WebSocketSession session, CloseStatus status) throws Exception {
super.afterConnectionClosed(session, status);
logger.info("-----client close");
}
@Override
public void handleTransportError(WebSocketSession session, Throwable exception) throws Exception {
super.handleTransportError(session, exception);
logger.error("-----client error", exception);
}
@Override
protected void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception {
super.handleTextMessage(session, message);
logger.info("-----client text message:{}", message.getPayload());
if ("DEF".equals(message.getPayload())){
session.close();
}
}
@Override
protected void handleBinaryMessage(WebSocketSession session, BinaryMessage message) throws Exception {
super.handleBinaryMessage(session, message);
logger.info("-----client binary message:{}", message.getPayload());
}
@Override
protected void handlePongMessage(WebSocketSession session, PongMessage message) throws Exception {
super.handlePongMessage(session, message);
logger.info("-----client pong message:{}", message.getPayload());
}
@Override
public void handleMessage(WebSocketSession session, WebSocketMessage<?> message) throws Exception {
super.handleMessage(session, message);
logger.info("-----client message:{}", message.getPayload());
// 所有message 都会运行到这里，一般情况不重写。
}
}
连接方法
StandardWebSocketClient standardWebSocketClient = new StandardWebSocketClient();
WebSocketConnectionManager webSocketConnectionManager = new WebSocketConnectionManager(standardWebSocketClient, webSocketClientHandler, "ws://localhost:8181/websocket/server2");
webSocketConnectionManager.setOrigin("*");
HttpHeaders headers = new HttpHeaders();
headers.set("k", "v");
webSocketConnectionManager.setHeaders(headers);
webSocketConnectionManager.start();
连接后Log信息
2021-10-30 11:12:20.997 INFO 15779 --- [nio-8181-exec-1] o.s.w.s.c.WebSocketConnectionManager : Starting WebSocketConnectionManager
2021-10-30 11:12:20.997 INFO 15779 --- [nio-8181-exec-1] o.s.w.s.c.WebSocketConnectionManager : Connecting to WebSocket at ws://localhost:8181/websocket/server2
2021-10-30 11:12:26.049 INFO 15779 --- [nio-8181-exec-2] c.e.w.s.WebSocketServerInterceptor : -----server beforeHandshake
2021-10-30 11:12:26.050 INFO 15779 --- [nio-8181-exec-2] c.e.w.s.WebSocketServerInterceptor : -----server beforeHandshake request Headers :[sec-websocket-key:"C4QJYOfTt266k/88DfM6Lg==", connection:"upgrade", sec-websocket-version:"13", host:"localhost:8181", k:"v", upgrade:"websocket"]
2021-10-30 11:12:26.052 INFO 15779 --- [nio-8181-exec-2] c.e.w.s.WebSocketServerInterceptor : -----server beforeHandshake: attributes{}
2021-10-30 11:12:26.067 INFO 15779 --- [nio-8181-exec-2] c.e.w.s.WebSocketServerInterceptor : -----server afterHandshake
2021-10-30 11:12:26.091 INFO 15779 --- [nio-8181-exec-2] c.e.w.spring2.WebSocketServerHandler : -----server open
2021-10-30 11:12:26.091 INFO 15779 --- [cTaskExecutor-1] c.e.w.spring2.WebSocketClientHandler : -----client open
2021-10-30 11:12:26.109 INFO 15779 --- [cTaskExecutor-1] o.s.w.s.c.WebSocketConnectionManager : Successfully connected
2021-10-30 11:12:26.110 INFO 15779 --- [nio-8181-exec-3] c.e.w.spring2.WebSocketServerHandler : -----server text message:ABC
2021-10-30 11:12:26.114 INFO 15779 --- [lient-AsyncIO-2] c.e.w.spring2.WebSocketClientHandler : -----client text message:DEF
2021-10-30 11:12:26.114 INFO 15779 --- [nio-8181-exec-3] c.e.w.spring2.WebSocketServerHandler : -----server message:ABC
2021-10-30 11:12:26.114 INFO 15779 --- [lient-AsyncIO-2] c.e.w.spring2.WebSocketClientHandler : -----client close
2021-10-30 11:12:26.114 INFO 15779 --- [lient-AsyncIO-2] c.e.w.spring2.WebSocketClientHandler : -----client message:DEF
2021-10-30 11:12:26.115 INFO 15779 --- [nio-8181-exec-4] c.e.w.spring2.WebSocketServerHandler : -----server close
总结
@ServerEndpoint() 这种方式的，操作简单，方法封装的很好，但是不能拦截 WebSocket 的请求，也就不能活去header 值，加入需要校验，那么就会不知所措。
WebSocketConfigurer 这种方法，操作起来稍微复杂一些，但是可以自己设置拦截器，拦截请求，能获取到请求中的所有的内容。
他们都各有利弊，根据自己项目的实际情况来选择使用哪种方式。
最后demo地址：https://github.com/wdmxzf/java-example/tree/webSocket
