1.root 是server
server -> HandlerCollection -> ContextHandlerCollection (pathmap) -> ContextHandler
而如果ContextHandler是屬於WebAppContext的話。其下包含了一連串的handler
WebAppContext -> SessionHandler -> SecurityHandler -> ServletHandler
原文：
- The Server
delegates the request to the its configured handler, which is normally an instance of HandlerCollection.
Server分派request給屬於server的handler，這常常是一個HandlerCollection的實例。
- The HandlerCollection acts like Jetty 5, and calls each of it's contained handlers in turn. Typically it is configured with
a ContextHandlerCollection, a DefaultHandler and a RequestLogHandler. This allows a request to be handled by a context or the default handler, and then be passed to the request log handler.
HandlerCollection會依序呼叫其下的每一個Handler，慣例上，其下會有ContextHandlerCollection,DefaultHandler,RequestHandler.
- The ContextHandlerCollection
maintains a map of context path to lists of ContextHandlers. For a given request, each the URI is used to find matching context paths, and each is called in turn until the request is handled.
ContextHandlerCollection維護一個path的map，根據request的URI mapping到其下對應的ContextHandler
- If the ContextHandler accepts a request (it may reject it due to virtual hosts), it will delegate the request to a nested handler and for the duration of that call it will set:
- the request context path
- the current thread context classloader
- the resource base
- the error handler
- context attributes and init parameters.
- Typically the ContextHandler will be an instance of WebAppContext and will thus contain a nested chain of SessionHandler, SecurityHandler and ServletHandler. The request is delegated to the first handler in this chain, a SessionHandler
- The SessionHandler will examine the request for any session ID to be activated and will activate the mechanism for creating new sessions before delegating the request to the SecurityHandler.
- The SecurityHandler will check any constraints and authentication before delegating the request to the ServletHandler
- The ServletHandler implements the dispatch to Filters and Servlets to handle the request according to the servlet specification.
簡單範例程式
public static void main(String[] args) {
Server service = new Server();
// connector Connector selconnector = new SelectChannelConnector();
selconnector.setPort(80);
service.setConnectors(new Connector[] { selconnector });
// thread pool BoundedThreadPool pool = new BoundedThreadPool();
pool.setMinThreads(10);
pool.setMaxThreads(100);
service.setThreadPool(pool);
// handler collection HandlerList handlerlist = new HandlerList();
service.setHandlers(new Handler[] { handlerlist, new DefaultHandler(), new RequestLogHandler() });
// static resource handler ContextHandler resContext = new ContextHandler(handlerlist, "/html");
ResourceHandler reshandler = new ResourceHandler();
reshandler.setResourceBase("./html/");
resContext.setHandler(reshandler);
// dynamic resource handler WebAppContext webappcontext = new WebAppContext(handlerlist, "./webapp/", "/webapp");
try {
service.join();
service.start();
} catch (InterruptedException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
