ServletContextImpl.java 文件源码

@Override
public void addListener(final Class<? extends EventListener> listenerClass) {
    ensureNotInitialized();
    ensureNotProgramaticListener();
    if (ApplicationListeners.listenerState() != NO_LISTENER &&
            ServletContextListener.class.isAssignableFrom(listenerClass)) {
        throw UndertowServletMessages.MESSAGES.cannotAddServletContextListener();
    }
    InstanceFactory<? extends EventListener> factory = null;
    try {
        factory = deploymentInfo.getClassIntrospecter().createInstanceFactory(listenerClass);
    } catch (Exception e) {
        throw new IllegalArgumentException(e);
    }
    final ListenerInfo listener = new ListenerInfo(listenerClass, factory);
    deploymentInfo.addListener(listener);
    deployment.getApplicationListeners().addListener(new ManagedListener(listener, true));
}