javax.naming.NameNotFoundException: Name [aa.bb.cc/xx] is not bound in this Context. Unable to find [aa.bb.cc]

今天尝试把一个SpringBoot项目由jdk11转移为jdk8，在IDEA里运行一切正常。打包，部署到tomcat启动后，在客户端调用WebSocket出现如下异常：

java.lang.IllegalArgumentException: javax.websocket.DeploymentException: Endpoint instance creation failed
        at org.apache.tomcat.websocket.server.WsHttpUpgradeHandler.init(WsHttpUpgradeHandler.java:139)
        at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:942)
        at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1732)
        at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
        at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)
        at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
        at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
        at java.lang.Thread.run(Thread.java:748)
    Caused by: javax.websocket.DeploymentException: Endpoint instance creation failed
        at org.apache.tomcat.websocket.WsSession.<init>(WsSession.java:278)
        at org.apache.tomcat.websocket.server.WsHttpUpgradeHandler.init(WsHttpUpgradeHandler.java:127)
        ... 7 more
    Caused by: javax.naming.NameNotFoundException: Name [cn.aa.bb.cc/userService] is not bound in this Context. Unable to find [cn.aa.bb.cc].
        at org.apache.naming.NamingContext.lookup(NamingContext.java:840)
        at org.apache.naming.NamingContext.lookup(NamingContext.java:172)
        at org.apache.catalina.core.DefaultInstanceManager.lookupFieldResource(DefaultInstanceManager.java:577)
        at org.apache.catalina.core.DefaultInstanceManager.processAnnotations(DefaultInstanceManager.java:480)
        at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:173)
        at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:142)
        at org.apache.tomcat.websocket.WsSession.<init>(WsSession.java:275)
        ... 8 more

在网上搜索了一阵也没有找到解决办法。回看异常本身，cn.aa.bb.cc/userService 有点问题，cn.aa.bb.cc是Controller类，userService 是类成员变量。通过 @Resource 初始化userService。从异常来看是由于初始化失败导致的。

    @Resource
    private UserService userService;

将Resource改为Autowired后，再部署运行就没问题了。

    @Autowired
    private UserService userService;

看来是找不到合适的类来初始化userService啊。