问题：

为了分析问题，我不得不编写一个简单的Java Web套接字客户端站点代码，并使用基于stomp的Web套接字代理连接到服务器端基于Spring的应用程序。

解决方案：

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>com.rnd</groupId><artifactId>SockWebsocketClient</artifactId><version>1.0-SNAPSHOT</version><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.0.3.RELEASE</version></parent><dependencies><dependency><groupId>org.springframework</groupId><artifactId>spring-messaging</artifactId><version>5.0.7.RELEASE</version></dependency><dependency><groupId>com.fasterxml.jackson.core</groupId><artifactId>jackson-databind</artifactId><version>2.9.5</version></dependency><dependency><groupId>org.apache.tomcat.embed</groupId><artifactId>tomcat-embed-websocket</artifactId><version>9.0.8</version></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-dependencies</artifactId><version>2.0.2.RELEASE</version><type>pom</type></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-context</artifactId><version>5.0.7.RELEASE</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-websocket</artifactId><version>5.0.7.RELEASE</version></dependency></dependencies>
</project>

Sock JS客户端

它是主要的班级，是做基础工作的简单班级。 由于当今大多数Web套接字都打算使用SSL，因此尝试通过创建虚拟TrustManager来传递信任管理器问题。

此代码的输入是您要订阅的主题字符串。

另外，不要在运行前更改代码中的<URL>字符串，指向您的Web套接字url。

package com.client;import org.springframework.messaging.Message;
import org.springframework.messaging.MessageHeaders;
import org.springframework.messaging.converter.MessageConverter;
import org.springframework.messaging.converter.SimpleMessageConverter;
import org.springframework.messaging.converter.StringMessageConverter;
import org.springframework.messaging.simp.stomp.StompHeaders;
import org.springframework.web.socket.WebSocketHttpHeaders;
import org.springframework.web.socket.client.standard.StandardWebSocketClient;
import org.springframework.web.socket.messaging.WebSocketStompClient;
import org.springframework.web.socket.sockjs.client.Transport;
import org.springframework.web.socket.sockjs.client.WebSocketTransport;
import org.springframework.web.socket.sockjs.frame.Jackson2SockJsMessageCodec;import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.SSLContext;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;
import java.net.URI;
import java.security.KeyManagementException;
import java.security.NoSuchAlgorithmException;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;public class SockJsClient {public static void main(String[] args) {try {StandardWebSocketClient simpleWebSocketClient = new StandardWebSocketClient();TrustManager[] trustAllCerts = new TrustManager[] {new X509TrustManager() {public X509Certificate[] getAcceptedIssuers() {return null;}public void checkClientTrusted(X509Certificate[] certs, String authType) {}public void checkServerTrusted(X509Certificate[] certs, String authType) {}}};SSLContext sc = SSLContext.getInstance("SSL");sc.init(null, trustAllCerts, new java.security.SecureRandom());HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());Map<String, Object> properties = new HashMap<>();properties.put("org.apache.tomcat.websocket.SSL_CONTEXT", sc);simpleWebSocketClient.setUserProperties(properties);List<Transport> transports = new ArrayList();transports.add(new WebSocketTransport(simpleWebSocketClient));org.springframework.web.socket.sockjs.client.SockJsClient sockJsClient = new org.springframework.web.socket.sockjs.client.SockJsClient(transports);sockJsClient.setMessageCodec(new Jackson2SockJsMessageCodec());WebSocketStompClient stompClient = new WebSocketStompClient(sockJsClient);stompClient.setMessageConverter(new MessageConverter() {@Overridepublic Object fromMessage(Message<?> message, Class<?> aClass) {return new String((byte[])message.getPayload());}@Overridepublic Message<?> toMessage(Object o, MessageHeaders messageHeaders) {return null;}});// url : pointing to websocket as sockJs first tries to get info by sending a HTTP request// and then sends an upgrade request to ws or wss. So your url should be some thing like htttp://URI stompUrlEndpoint = new URI("<url>");WebSocketHttpHeaders handshakeHeaders = new WebSocketHttpHeaders();StompHeaders connectHeaders = new StompHeaders();/*Can set connection header like login , passcode in connectHeaders  */stompClient.connect(stompUrlEndpoint.toString(), handshakeHeaders, connectHeaders, new SessionHandler(args[0]), new Object[0]);Thread.sleep(30000);stompClient.stop();} catch (Exception e) {e.printStackTrace();}}
}

会话处理程序

每个套接字连接都需要一个会话处理程序，这里是一个用于处理连接设置和传入消息的会话处理程序。

package com.client;import org.springframework.messaging.simp.stomp.StompCommand;
import org.springframework.messaging.simp.stomp.StompFrameHandler;
import org.springframework.messaging.simp.stomp.StompHeaders;
import org.springframework.messaging.simp.stomp.StompSession;
import org.springframework.messaging.simp.stomp.StompSessionHandlerAdapter;import java.lang.reflect.Type;public class SessionHandler extends StompSessionHandlerAdapter {private final String topicName ;public SessionHandler(String topicName) {this.topicName = topicName;}@Overridepublic void afterConnected(StompSession session, StompHeaders connectedHeaders) {this.subscribeTo(session);}@Overridepublic void handleException(StompSession session,StompCommand command,StompHeaders headers,byte[] payload,Throwable exception ) {exception.printStackTrace();}public void handleFrame(StompHeaders headers, Object payload) {System.out.println(payload.toString());}@Overridepublic void handleTransportError(StompSession session, Throwable exception) {exception.printStackTrace();}private void subscribeTo(StompSession session) {StompHeaders headers = new StompHeaders();headers.add("id","websocket-session-standalone-0");headers.add("destination",topicName);session.subscribe(headers, new StompFrameHandler() {@Overridepublic Type getPayloadType(StompHeaders stompHeaders) {return String.class;}@Overridepublic void handleFrame(StompHeaders stompHeaders, Object o) {System.out.println( " Message is " +o.toString());}});}
}

翻译自: https://www.javacodegeeks.com/2019/08/web-socket-java-client-stomp-spring-server-side.html