Are you running in a Servlet container that supports JSR-356?

java.lang.IllegalArgumentException: No 'javax.websocket.server.ServerContainer' ServletContext attribute. Are you running in a Servlet container that supports JSR-356?

将websocket的demo拉入自己的项目报错，其实显示的是web容器不包括这个JSR-356，
springboot自带的有tomcat,所以需要看下你更换的web容器，我换的是undertow容器，所以我的springboot启动类需要修改一下

<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-websocket</artifactId>
 </dependency>

 <dependency>
     <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-starter-undertow</artifactId>
 </dependency>

这个问题我也是一脸懵逼，也找不到相同的，所以还是仔细观察才能解决bug。要仔细查看启动代码