Logging thread exceptions in tomcat environment

I have wrote a piece of java code for a springboot controller:

@GetMapping("/exception")
    public void exceptionInThread() {
        Thread newThread = new Thread(new Runnable() {
                @Override
                public void run() {
                    throw new NullPointerException();
                }
        });
        log.info("daemon: {}, threadGroup: {}, defaultUncaught: {}",
                 newThread.isDaemon(),
                 newThread.getThreadGroup(),
                 Thread.getDefaultUncaughtExceptionHandler()
                 );
        newThread.start();
    }

After I compile the project, I run java -jar application.jar and call restapi (http://localhost:8080/exception). I can get a NPE trace.

But in our production environment, we compile sprintboot in to a WAR and put the WAR into Tomcat's webapps directory. Then happens the weird thing. When I triggered the restapi to run the method, there is not any NPE trace popped out. As if there is a default uncaught exception handler set underneath which consume the exception without a trace. But the application log I printed is all the same in both environments (sprintboot application & tomcat webapp):

2017-07-19 10:35:33.479  INFO 38070 --- [nio-8080-exec-1] com.ruan.restful.ThreadController  : daemon: true, threadGroup: java.lang.ThreadGroup[name=main,maxpri=10], defaultUncaught: null

That confuses me a lot. Is there something Tomcat set for me? Can you guys give me some pointers?