[网络协议]springboot+websocket采坑记录

问题描述：

项目中因为用rtsp向前端推送图片时，引入了websocket报如下错误：?java.lang.IllegalStateException: javax.websocket.server.ServerContainer not available

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'serverEndpointExporter' defined in class path resource [org/xxx/modules/xxx/config/WebSocketConfig.class]: Invocation of init method failed; nested exception is java.lang.IllegalStateException: javax.websocket.server.ServerContainer not available
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1794)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:594)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:516)
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:324)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:322)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:897)
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:879)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:551)
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141)
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:747)
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:405)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:315)
	at org.springframework.boot.builder.SpringApplicationBuilder.run(SpringApplicationBuilder.java:140)
	at org.springblade.core.launch.BladeApplication.run(BladeApplication.java:50)
	at org.springblade.Application.main(Application.java:36)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at com.intellij.rt.execution.CommandLineWrapper.main(CommandLineWrapper.java:67)
Caused by: java.lang.IllegalStateException: javax.websocket.server.ServerContainer not available
	at org.springframework.util.Assert.state(Assert.java:76)
	at org.springframework.web.socket.server.standard.ServerEndpointExporter.afterPropertiesSet(ServerEndpointExporter.java:107)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1853)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1790)
	... 21 common frames omitted

代码配置

@Configuration
public class WebSocketConfig {
	@Bean
	public ServerEndpointExporter serverEndpointExporter(){
		return new ServerEndpointExporter();
	}
}

心历路程

遇见问题首先是百度一下，总结可能出现该问题的是两种情况：

1项目中含有websocket的@ServerEndpoint注解的时候,如果项目是springboot项目,去除内置tomcat的时候会把websocket的包也给删除掉,所以需要手动加上.加上这个包

2在SpringBootTest后加上：webEnvironment =SpringBootTest.WebEnvironment.RANDOM_PORT，意思是创建Web应用程序上下文（基于响应或基于servlet），原因:websocket是需要依赖tomcat等容器的启动。所以在测试过程中我们要真正的启动一个tomcat作为容器。

问题解决

上述两种情况都不能解决我的问题，启动还是报错；突然搜一篇关于undertwo不支持websocket的文章；专程去搜索了下undertwo的文章；文章写的好好的别人undertwo是支持websocke的；

不过最后从这儿得到了启示：因为springboot内嵌的tomcat,tomcat中的websocket会有冲突，只需要我们排除就好，自此困扰我半天的问题终于解决，与underttwo没有关系；

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
    <exclusions>
        <exclusion>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
        </exclusion>
    </exclusions>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-undertow</artifactId>
</dependency>

最后希望能解决你们的问题，解决了希望大家关注下，留言区评论下,谢谢

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