嵌入式tomcat 8.0.21中的Spring websocket

Posted 2023-02-16

【中文标题】嵌入式tomcat 8.0.21中的Spring websocket

【英文标题】：Spring websocket in embedded tomcat 8.0.21

【发布时间】：2016-08-29 13:26:22

【问题描述】：

我想基于一个示例创建一个 WebSocket。唯一的变化是我在嵌入式 tomcat 中运行我的应用程序。

package com.test.websocket;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.socket.CloseStatus;
import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketSession;
import org.springframework.web.socket.handler.AbstractWebSocketHandler;

public class WebSocketTest extends AbstractWebSocketHandler 
    private static Logger logger = LoggerFactory.getLogger(WebSocketTest.class);

    @Override
    protected void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception 
        logger.debug("Recieved websocket message: " + message);

        session.sendMessage(new TextMessage("thanks"));
    

    @Override
    public void afterConnectionEstablished(WebSocketSession session) throws Exception 
        logger.info("WebSocket connection established!");
    

    @Override
    public void afterConnectionClosed(WebSocketSession session, CloseStatus status) throws Exception 
        logger.info("WebSocket connection closed!");
    

配置（websocket.spring.xml）：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:websocket="http://www.springframework.org/schema/websocket"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
              http://www.springframework.org/schema/beans/spring-beans.xsd
              http://www.springframework.org/schema/websocket
              http://www.springframework.org/schema/websocket/spring-websocket.xsd">

       <websocket:handlers>
              <websocket:mapping path="/socket" handler="webSocketHandler"/>
       </websocket:handlers>

       <bean id="webSocketHandler" class="com.test.websocket.WebSocketTest"/>
</beans>

Servlet 映射在 /websocket/*

从日志看来，spring-websocket 似乎已成功初始化，但是当我尝试连接到 websocket 时出现此错误。

Servlet.service() for servlet [spring-websocket] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.web.socket.server.HandshakeFailureException: Uncaught failure for request http://localhost:9876/websocket/socket; nested exception is java.lang.IllegalArgumentException: No 'javax.websocket.server.ServerContainer' ServletContext attribute. Are you running in a Servlet container that supports JSR-356?] with root cause

依赖项是：tomcat-embed-core、tomcat-embed-websocket、tomcat-juli 以及由于 (Spring websocket example - error - Are you running in a Servlet container that supports J SR-356?) javax.websocket-api 和 tomcat-websocket

我错过了什么？

提前致谢！

【参考方案1】：

也许我找到了解决您问题的方法。

您需要使用 WsSci servlet 容器初始化器来嵌入 tomcat 上下文：

context.addServletContainerInitializer(new WsSci(), null);

https://github.com/spring-projects/spring-boot/issues/439

【讨论】：

在没有 Spring Boot 的情况下似乎无法工作，例如在使用 Gradle Tomcat 插件时。