/** Creates the action context and initializes the thread local */
public ActionContext createActionContext(
HttpServletRequest request, HttpServletResponse response) {
ActionContext ctx;
Integer counter = 1;
Integer oldCounter = (Integer) request.getAttribute(CLEANUP_RECURSION_COUNTER);
if (oldCounter != null) {
counter = oldCounter + 1;
}
ActionContext oldContext = ActionContext.getContext();
if (oldContext != null) {
// detected existing context, so we are probably in a forward
ctx = new ActionContext(new HashMap<String, Object>(oldContext.getContextMap()));
} else {
ValueStack stack =
dispatcher.getContainer().getInstance(ValueStackFactory.class).createValueStack();
stack
.getContext()
.putAll(dispatcher.createContextMap(request, response, null, servletContext));
// 利用ValueStack的context属性实例化ActionContext
ctx = new ActionContext(stack.getContext());
}
request.setAttribute(CLEANUP_RECURSION_COUNTER, counter);
ActionContext.setContext(ctx);
return ctx;
}
/**
*
* <li>forceLookup 为false时，优先返回(ActionMapping) request.getAttribute(STRUTS_ACTION_MAPPING_KEY)
* <li>forceLookup 为true时，每次都去获取ActionMapper实例 <br>
* <br>
* Finds and optionally creates an {@link ActionMapping}. if forceLookup is false, it first
* looks in the current request to see if one has already been found, otherwise, it creates it
* and stores it in the request. No mapping will be created in the case of static resource
* requests or unidentifiable requests for other servlets, for example.
*
* @param forceLookup if true, the action mapping will be looked up from the ActionMapper
* instance, ignoring if there is one in the request or not
*/
public ActionMapping findActionMapping(
HttpServletRequest request, HttpServletResponse response, boolean forceLookup) {
ActionMapping mapping = (ActionMapping) request.getAttribute(STRUTS_ACTION_MAPPING_KEY);
if (mapping == null || forceLookup) {
try {
// ActionMapper默认实例是{ @link org.apache.struts2.dispatcher.mapper.DefaultActionMapper}
mapping =
dispatcher
.getContainer()
.getInstance(ActionMapper.class)
.getMapping(request, dispatcher.getConfigurationManager());
if (mapping != null) {
// 设置mapping到request属性，
request.setAttribute(STRUTS_ACTION_MAPPING_KEY, mapping);
}
} catch (Exception ex) {
dispatcher.sendError(
request, response, servletContext, HttpServletResponse.SC_INTERNAL_SERVER_ERROR, ex);
}
}
return mapping;
}