FrameworkServlet.processRequest（删减版）
protected final void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// (1)
LocaleContext previousLocaleContext = LocaleContextHolder.getLocaleContext();
LocaleContext localeContext = buildLocaleContext(request);
RequestAttributes previousAttributes = RequestContextHolder.getRequestAttributes();
ServletRequestAttributes requestAttributes = buildRequestAttributes(request, response, previousAttributes);
// (2)
initContextHolders(request, localeContext, requestAttributes);
doService(request, response);
// (3)
resetContextHolders(request, previousLocaleContext, previousAttributes);
if (requestAttributes != null) {
requestAttributes.requestCompleted();
}
}
两个ContextHolder做的事情是一样的：设置和重置
- 获取以前的值
- 设置新值
new SimpleLocaleContext(request.getLocale())和new ServletRequestAttributes(request, response) - 设置回原来的值
这里我们产生了一些问题
-
previousLocaleContext和previousAttributes从哪里来的？ - 为什么把ContextHolder中的对象换成新的，doService后又要重置ContextHolder？
-
requestAttributes.requestCompleted()做了些什么？ - 为什么ContextHolder要用ThreadLocal？为什么有NamedThreadLocal和NamedInheritableThreadLocal，它们有啥区别？
//todo
