]> WPIA git - gigi.git/blobdiff - lib/jetty/org/eclipse/jetty/server/handler/AsyncDelayHandler.java
Merge branch 'libs/jetty/local'
[gigi.git] / lib / jetty / org / eclipse / jetty / server / handler / AsyncDelayHandler.java
diff --git a/lib/jetty/org/eclipse/jetty/server/handler/AsyncDelayHandler.java b/lib/jetty/org/eclipse/jetty/server/handler/AsyncDelayHandler.java
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+//
+//  ========================================================================
+//  Copyright (c) 1995-2016 Mort Bay Consulting Pty. Ltd.
+//  ------------------------------------------------------------------------
+//  All rights reserved. This program and the accompanying materials
+//  are made available under the terms of the Eclipse Public License v1.0
+//  and Apache License v2.0 which accompanies this distribution.
+//
+//      The Eclipse Public License is available at
+//      http://www.eclipse.org/legal/epl-v10.html
+//
+//      The Apache License v2.0 is available at
+//      http://www.opensource.org/licenses/apache2.0.php
+//
+//  You may elect to redistribute this code under either of these licenses.
+//  ========================================================================
+//
+
+package org.eclipse.jetty.server.handler;
+
+import java.io.IOException;
+
+import javax.servlet.AsyncContext;
+import javax.servlet.DispatcherType;
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import org.eclipse.jetty.server.Request;
+
+
+/* ------------------------------------------------------------ */
+/** A handler wrapper that provides the framework to asynchronously
+ * delay the handling of a request.  While it uses standard servlet 
+ * API for asynchronous servlets, it adjusts the dispatch type of the 
+ * request so that it does not appear to be asynchronous during the
+ * delayed dispatch.
+ * 
+ */
+public class AsyncDelayHandler extends HandlerWrapper
+{
+    public final static String AHW_ATTR = "o.e.j.s.h.AsyncHandlerWrapper";
+
+    /* ------------------------------------------------------------ */
+    @Override
+    public void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException
+    {
+        if (!isStarted() || _handler==null)
+            return;
+        
+        // Get the dispatcher types
+        DispatcherType ctype = baseRequest.getDispatcherType();
+        DispatcherType dtype = (DispatcherType)baseRequest.getAttribute(AHW_ATTR);
+        Object async_context_path=null;
+        Object async_path_info=null;
+        Object async_query_string=null;
+        Object async_request_uri=null;
+        Object async_servlet_path=null;
+        
+        // Is this request a restarted one?
+        boolean restart=false;
+        if (dtype!=null)
+        {
+            // fake the dispatch type to the original
+            baseRequest.setAttribute(AHW_ATTR,null);
+            baseRequest.setDispatcherType(dtype);
+            restart=true;
+            
+            async_context_path=baseRequest.getAttribute(AsyncContext.ASYNC_CONTEXT_PATH);
+            baseRequest.setAttribute(AsyncContext.ASYNC_CONTEXT_PATH,null);
+            async_path_info=baseRequest.getAttribute(AsyncContext.ASYNC_PATH_INFO);
+            baseRequest.setAttribute(AsyncContext.ASYNC_PATH_INFO,null);
+            async_query_string=baseRequest.getAttribute(AsyncContext.ASYNC_QUERY_STRING);
+            baseRequest.setAttribute(AsyncContext.ASYNC_QUERY_STRING,null);
+            async_request_uri=baseRequest.getAttribute(AsyncContext.ASYNC_REQUEST_URI);
+            baseRequest.setAttribute(AsyncContext.ASYNC_REQUEST_URI,null);
+            async_servlet_path=baseRequest.getAttribute(AsyncContext.ASYNC_SERVLET_PATH);
+            baseRequest.setAttribute(AsyncContext.ASYNC_SERVLET_PATH,null);
+        }
+        
+        // Should we handle this request now?
+        if (!startHandling(baseRequest,restart))
+        {
+            // No, so go async and remember dispatch type
+            AsyncContext context = baseRequest.startAsync();
+            baseRequest.setAttribute(AHW_ATTR,ctype);
+
+            delayHandling(baseRequest, context);
+            return;
+        }
+
+        // Handle the request
+        try
+        {
+            _handler.handle(target,baseRequest, request, response);
+        }
+        finally
+        {
+            if(restart)
+            {
+                // reset the request
+                baseRequest.setDispatcherType(ctype);
+                baseRequest.setAttribute(AsyncContext.ASYNC_CONTEXT_PATH,async_context_path);
+                baseRequest.setAttribute(AsyncContext.ASYNC_PATH_INFO,async_path_info);
+                baseRequest.setAttribute(AsyncContext.ASYNC_QUERY_STRING,async_query_string);
+                baseRequest.setAttribute(AsyncContext.ASYNC_REQUEST_URI,async_request_uri);
+                baseRequest.setAttribute(AsyncContext.ASYNC_SERVLET_PATH,async_servlet_path);
+            }
+            
+            // signal the request is leaving the handler
+            endHandling(baseRequest);
+        }
+        
+    }
+    
+    /* ------------------------------------------------------------ */
+    /** Called to indicate that a request has been presented for handling
+     * @param request The request to handle
+     * @param restart True if this request is being restarted after a delay
+     * @return True if the request should be handled now
+     */
+    protected boolean startHandling(Request request, boolean restart)
+    {
+        return true;
+    }
+
+    /* ------------------------------------------------------------ */
+    /** Called to indicate that a requests handling is being delayed/
+     * The implementation should arrange for context.dispatch() to be
+     * called when the request should be handled.  It may also set
+     * timeouts on the context. 
+     * 
+     * @param request The request to be delayed
+     * @param context The AsyncContext of the delayed request
+     */
+    protected void delayHandling(Request request,AsyncContext context)
+    {
+        context.dispatch();
+    }
+    
+    /* ------------------------------------------------------------ */
+    /** Called to indicated the handling of the request is ending.
+     * This is only the end of the current dispatch of the request and
+     * if the request is asynchronous, it may be handled again.
+     * @param request The request
+     */
+    protected void endHandling(Request request)
+    {
+        
+    }
+    
+    
+}