import javax.servlet.http.HttpSessionIdListener; //导入依赖的package包/类
/**
 * This method is used by injected code to register listeners for
 * {@link ServletContext}. If object argument is a {@link ServletContext} and
 * listener argument contains {@link HttpSessionListener} or
 * {@link HttpSessionAttributeListener}, the method will add them to list of
 * known listeners associated to {@link ServletContext}
 *
 * @param servletContext
 *          the active servlet context
 * @param listener
 *          the listener to use
 */
public void onAddListener(ServletContext servletContext, Object listener) {
  String contextPath = servletContext.getContextPath();
  ServletContextDescriptor scd = getDescriptor(servletContext);
  logger.debug("Registering listener {} for context {}", listener, contextPath);
  // As theoretically one class can implement many listener interfaces we
  // check if it implements each of supported ones
  if (listener instanceof HttpSessionListener) {
    scd.addHttpSessionListener((HttpSessionListener)listener);
  }
  if (listener instanceof HttpSessionAttributeListener) {
    scd.addHttpSessionAttributeListener((HttpSessionAttributeListener)listener);
  }
  if (ServletLevel.isServlet31) {
    // Guard the code inside block to avoid use of classes
    // that are not available in versions before Servlet 3.1
    if (listener instanceof HttpSessionIdListener) { // NOSONAR
      scd.addHttpSessionIdListener((HttpSessionIdListener)listener);
    }
  }
}
 

import javax.servlet.http.HttpSessionIdListener; //导入依赖的package包/类
private static boolean isWeb(final Class<?> beanClass) {
    if (Servlet.class.isAssignableFrom(beanClass)
        || Filter.class.isAssignableFrom(beanClass)) {
        return true;
    }
    if (EventListener.class.isAssignableFrom(beanClass)) {
        return HttpSessionAttributeListener.class.isAssignableFrom(beanClass)
               || ServletContextListener.class.isAssignableFrom(beanClass)
               || ServletRequestListener.class.isAssignableFrom(beanClass)
               || ServletContextAttributeListener.class.isAssignableFrom(beanClass)
               || HttpSessionListener.class.isAssignableFrom(beanClass)
               || HttpSessionBindingListener.class.isAssignableFrom(beanClass)
               || HttpSessionActivationListener.class.isAssignableFrom(beanClass)
               || HttpSessionIdListener.class.isAssignableFrom(beanClass)
               || ServletRequestAttributeListener.class.isAssignableFrom(beanClass);
    }

    return false;
}
 

import javax.servlet.http.HttpSessionIdListener; //导入依赖的package包/类
@Override
public void sessionIdChanged(RepositoryBackedSession session, String oldId) {
  // Session id change is only supported for Servlet 3.1+
  if (!ServletLevel.isServlet31) {
    return;
  }
  if (session instanceof HttpSession) {
    HttpSessionEvent event = new HttpSessionEvent((HttpSession)session);
    for (EventListener listener : descriptor.getHttpSessionIdListeners()) {
      ((HttpSessionIdListener)listener).sessionIdChanged(event, oldId);
    }
  }
}
 

import javax.servlet.http.HttpSessionIdListener; //导入依赖的package包/类
@Test
public void testOnAddListener() {
  ServletContextDescriptor scd = new ServletContextDescriptor(servletContext);
  when(servletContext.getAttribute(Attributes.SERVLET_CONTEXT_DESCRIPTOR)).thenReturn(scd);
  sessionHelpers.onAddListener(servletContext, "Dummy");
  assertTrue(scd.getHttpSessionListeners().isEmpty());
  assertTrue(scd.getHttpSessionIdListeners().isEmpty());
  assertTrue(scd.getHttpSessionAttributeListeners().isEmpty());
  HttpSessionListener listener = mock(HttpSessionListener.class);
  HttpSessionIdListener idListener = mock(HttpSessionIdListener.class);
  HttpSessionAttributeListener attributeListener = mock(HttpSessionAttributeListener.class);
  HttpSessionListener multiListener = mock(HttpSessionListener.class,
      withSettings().extraInterfaces(HttpSessionAttributeListener.class));
  HttpSessionAttributeListener attributeMultiListener = (HttpSessionAttributeListener)multiListener;
  sessionHelpers.onAddListener(servletContext, listener);
  assertThat(scd.getHttpSessionListeners(), hasItem(listener));
  assertTrue(scd.getHttpSessionIdListeners().isEmpty());
  assertTrue(scd.getHttpSessionAttributeListeners().isEmpty());
  sessionHelpers.onAddListener(servletContext, idListener);
  assertThat(scd.getHttpSessionListeners(), hasItem(listener));
  assertThat(scd.getHttpSessionIdListeners(), hasItem(idListener));
  assertTrue(scd.getHttpSessionAttributeListeners().isEmpty());
  sessionHelpers.onAddListener(servletContext, attributeListener);
  assertThat(scd.getHttpSessionListeners(), hasItem(listener));
  assertThat(scd.getHttpSessionIdListeners(), hasItem(idListener));
  assertThat(scd.getHttpSessionAttributeListeners(), hasItem(attributeListener));
  sessionHelpers.onAddListener(servletContext, multiListener);
  assertThat(scd.getHttpSessionListeners(), hasItem(listener));
  assertThat(scd.getHttpSessionListeners(), hasItem(multiListener));
  assertThat(scd.getHttpSessionIdListeners(), hasItem(idListener));
  assertThat(scd.getHttpSessionAttributeListeners(), hasItem(attributeListener));
  assertThat(scd.getHttpSessionAttributeListeners(), hasItem(attributeMultiListener));
}
 

import javax.servlet.http.HttpSessionIdListener; //导入依赖的package包/类
/**
 * Call any session id listeners registered.
 * Usually done by renewSessionId() method, but that is not used in appengine.
 * @param session
 * @param oldId
 */
public void callSessionIdListeners (AbstractSession session, String oldId) {
  HttpSessionEvent event = new HttpSessionEvent(session);
  for (HttpSessionIdListener l:_sessionIdListeners)
  {
      l.sessionIdChanged(event, oldId);
  }
}
 

import javax.servlet.http.HttpSessionIdListener; //导入依赖的package包/类
public void httpSessionIdChanged(final HttpSession session, final String oldSessionId) {
    final HttpSessionEvent sre = new HttpSessionEvent(session);
    for (int i = 0; i < httpSessionIdListeners.length; ++i) {
        this.<HttpSessionIdListener>get(httpSessionIdListeners[i]).sessionIdChanged(sre, oldSessionId);
    }
}
 

import javax.servlet.http.HttpSessionIdListener; //导入依赖的package包/类
HttpSessionIdListener getHttpSessionIdListener() {
    return this.sessionIdListener;
}
 

import javax.servlet.http.HttpSessionIdListener; //导入依赖的package包/类
private void initHttpSessionIdListener(EventListener listener) {
    if (listener instanceof HttpSessionIdListener) {
        this.sessionIdListener = (HttpSessionIdListener) listener;
    }
}