html:form
org.apache.struts.action.ActionServlet;
ActionServlet extends HttpServlet
doGet
doPost
process(request, response);
{
processor = getRequestProcessor(config);
processor.process(request, response);
}
RequestProcessor 没有继承任何的类，只是一个repquest的处理器，逻辑封装
方法
public void process(HttpServletRequest request,
HttpServletResponse response)
{
//封装request
request = processMultipart(request);
/*
详细：
protected HttpServletRequest processMultipart(HttpServletRequest request) {
if (!"POST".equalsIgnoreCase(request.getMethod())) {
return (request);
}
String contentType = request.getContentType();
if ((contentType != null) &&
contentType.startsWith("multipart/form-data")) {
return (new MultipartRequestWrapper(request));
} else {
return (request);
}
}
*/
// Identify the path component we will use to select a mapping
String path = processPath(request, response);
if (path == null) {
return;
}
//begin 可以忽略
if (log.isDebugEnabled()) {
log.debug("Processing a '" + request.getMethod() +
"' for path '" + path + "'");
}
// Select a Locale for the current user if requested
processLocale(request, response);
// Set the content type and no-caching headers if requested
processContent(request, response);
processNoCache(request, response);
// General purpose preprocessing hook
if (!processPreprocess(request, response)) {
return;
}
this.processCachedMessages(request, response);
//end 忽略
// Identify the mapping for this request
ActionMapping mapping = processMapping(request, response, path);
if (mapping == null) {
return;
}
/*详细
根据path找到mapping
*/
// Check for any role required to perform this action
if (!processRoles(request, response, mapping)) {
return;
}
//action form 的处理
// Process any ActionForm bean related to this request
ActionForm form = processActionForm(request, response, mapping);
/*
用mapping找actionform
protected ActionForm processActionForm(HttpServletRequest request,
HttpServletResponse response,
ActionMapping mapping) {
// Create (if necessary) a form bean to use
ActionForm instance = RequestUtils.createActionForm
(request, mapping, moduleConfig, servlet);
/*详细
ActionForm instance = lookupActionForm(request, attribute, mapping.getScope());
if (instance != null && canReuseActionForm(instance, config)) {
return (instance);
否则
return createActionForm(config, servlet);
*/
if (instance == null) {
return (null);
}
// Store the new instance in the appropriate scope
if (log.isDebugEnabled()) {
log.debug(" Storing ActionForm bean instance in scope '" +
mapping.getScope() + "' under attribute key '" +
mapping.getAttribute() + "'");
}
if ("request".equals(mapping.getScope())) {
request.setAttribute(mapping.getAttribute(), instance);
} else {
HttpSession session = request.getSession();
session.setAttribute(mapping.getAttribute(), instance);
}
return (instance);
}
*/
processPopulate(request, response, form, mapping);
/*
RequestUtils.populate(form, mapping.getPrefix(), mapping.getSuffix(),
request);
*/
if (!processValidate(request, response, form, mapping)) {
return;
}
/*
protected boolean processValidate(HttpServletRequest request,
HttpServletResponse response,
ActionForm form,
ActionMapping mapping)
throws IOException, ServletException {
if (form == null) {
return (true);
}
// Was this request cancelled?
if (request.getAttribute(Globals.CANCEL_KEY) != null) {
if (log.isDebugEnabled()) {
log.debug(" Cancelled transaction, skipping validation");
}
return (true);
}
// Has validation been turned off for this mapping?
if (!mapping.getValidate()) {
return (true);
}
// Call the form bean's validation method
if (log.isDebugEnabled()) {
log.debug(" Validating input form properties");
}
ActionMessages errors = form.validate(mapping, request);
if ((errors == null) || errors.isEmpty()) {
if (log.isTraceEnabled()) {
log.trace(" No errors detected, accepting input");
}
return (true);
}
// Special handling for multipart request
if (form.getMultipartRequestHandler() != null) {
if (log.isTraceEnabled()) {
log.trace(" Rolling back multipart request");
}
form.getMultipartRequestHandler().rollback();
}
// Was an input path (or forward) specified for this mapping?
String input = mapping.getInput();
if (input == null) {
if (log.isTraceEnabled()) {
log.trace(" Validation failed but no input form available");
}
response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR,
getInternal().getMessage("noInput",
mapping.getPath()));
return (false);
}
// Save our error messages and return to the input form if possible
if (log.isDebugEnabled()) {
log.debug(" Validation failed, returning to '" + input + "'");
}
request.setAttribute(Globals.ERROR_KEY, errors);
if (moduleConfig.getControllerConfig().getInputForward()) {
ForwardConfig forward = mapping.findForward(input);
processForwardConfig( request, response, forward);
} else {
internalModuleRelativeForward(input, request, response);
}
return (false);
}
*/
// Process a forward or include specified by this mapping
if (!processForward(request, response, mapping)) {
return;
}
if (!processInclude(request, response, mapping)) {
return;
}
// Create or acquire the Action instance to process this request
Action action = processActionCreate(request, response, mapping);
if (action == null) {
return;
}
// Call the Action instance itself
ActionForward forward =
processActionPerform(request, response,
action, form, mapping);
/*
protected ActionForward
processActionPerform(HttpServletRequest request,
HttpServletResponse response,
Action action,
ActionForm form,
ActionMapping mapping)
throws IOException, ServletException {
try {
return (action.execute(mapping, form, request, response));
} catch (Exception e) {
return (processException(request, response,
e, form, mapping));
}
}
*/
// Process the returned ActionForward instance
processForwardConfig(request, response, forward);
protected void processForwardConfig(HttpServletRequest request,
HttpServletResponse response,
ForwardConfig forward)
throws IOException, ServletException {
if (forward == null) {
return;
}
if (log.isDebugEnabled()) {
log.debug("processForwardConfig(" + forward + ")");
}
String forwardPath = forward.getPath();
String uri = null;
// paths not starting with / should be passed through without any processing
// (ie. they're absolute)
if (forwardPath.startsWith("/")) {
uri = RequestUtils.forwardURL(request, forward, null); // get module relative uri
} else {
uri = forwardPath;
}
if (forward.getRedirect()) {
// only prepend context path for relative uri
if (uri.startsWith("/")) {
uri = request.getContextPath() + uri;
}
response.sendRedirect(response.encodeRedirectURL(uri));
} else {
doForward(uri, request, response);
}
}
}
protected void doForward(
String uri,
HttpServletRequest request,
HttpServletResponse response)
throws IOException, ServletException {
// Unwrap the multipart request, if there is one.
if (request instanceof MultipartRequestWrapper) {
request = ((MultipartRequestWrapper) request).getRequest();
}
RequestDispatcher rd = getServletContext().getRequestDispatcher(uri);
if (rd == null) {
response.sendError(
HttpServletResponse.SC_INTERNAL_SERVER_ERROR,
getInternal().getMessage("requestDispatcher", uri));
return;
}
rd.forward(request, response);
}
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