--- /dev/null
+//
+// ========================================================================
+// Copyright (c) 1995-2014 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.ServletException;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import org.eclipse.jetty.server.Request;
+
+
+/* ------------------------------------------------------------ */
+/** ScopedHandler.
+ *
+ * A ScopedHandler is a HandlerWrapper where the wrapped handlers
+ * each define a scope.
+ *
+ * <p>When {@link #handle(String, Request, HttpServletRequest, HttpServletResponse)}
+ * is called on the first ScopedHandler in a chain of HandlerWrappers,
+ * the {@link #doScope(String, Request, HttpServletRequest, HttpServletResponse)} method is
+ * called on all contained ScopedHandlers, before the
+ * {@link #doHandle(String, Request, HttpServletRequest, HttpServletResponse)} method
+ * is called on all contained handlers.</p>
+ *
+ * <p>For example if Scoped handlers A, B & C were chained together, then
+ * the calling order would be:</p>
+ * <pre>
+ * A.handle(...)
+ * A.doScope(...)
+ * B.doScope(...)
+ * C.doScope(...)
+ * A.doHandle(...)
+ * B.doHandle(...)
+ * C.doHandle(...)
+ * </pre>
+ *
+ * <p>If non scoped handler X was in the chained A, B, X & C, then
+ * the calling order would be:</p>
+ * <pre>
+ * A.handle(...)
+ * A.doScope(...)
+ * B.doScope(...)
+ * C.doScope(...)
+ * A.doHandle(...)
+ * B.doHandle(...)
+ * X.handle(...)
+ * C.handle(...)
+ * C.doHandle(...)
+ * </pre>
+ *
+ * <p>A typical usage pattern is:</p>
+ * <pre>
+ * private static class MyHandler extends ScopedHandler
+ * {
+ * public void doScope(String target, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException
+ * {
+ * try
+ * {
+ * setUpMyScope();
+ * super.doScope(target,request,response);
+ * }
+ * finally
+ * {
+ * tearDownMyScope();
+ * }
+ * }
+ *
+ * public void doHandle(String target, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException
+ * {
+ * try
+ * {
+ * doMyHandling();
+ * super.doHandle(target,request,response);
+ * }
+ * finally
+ * {
+ * cleanupMyHandling();
+ * }
+ * }
+ * }
+ * </pre>
+ */
+public abstract class ScopedHandler extends HandlerWrapper
+{
+ private static final ThreadLocal<ScopedHandler> __outerScope= new ThreadLocal<ScopedHandler>();
+ protected ScopedHandler _outerScope;
+ protected ScopedHandler _nextScope;
+
+ /* ------------------------------------------------------------ */
+ /**
+ * @see org.eclipse.jetty.server.handler.HandlerWrapper#doStart()
+ */
+ @Override
+ protected void doStart() throws Exception
+ {
+ try
+ {
+ _outerScope=__outerScope.get();
+ if (_outerScope==null)
+ __outerScope.set(this);
+
+ super.doStart();
+
+ _nextScope= getChildHandlerByClass(ScopedHandler.class);
+
+ }
+ finally
+ {
+ if (_outerScope==null)
+ __outerScope.set(null);
+ }
+ }
+
+ /* ------------------------------------------------------------ */
+ /*
+ */
+ @Override
+ public final void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException
+ {
+ if (isStarted())
+ {
+ if (_outerScope==null)
+ doScope(target,baseRequest,request, response);
+ else
+ doHandle(target,baseRequest,request, response);
+ }
+ }
+
+ /* ------------------------------------------------------------ */
+ /*
+ * Scope the handler
+ */
+ public abstract void doScope(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response)
+ throws IOException, ServletException;
+
+ /* ------------------------------------------------------------ */
+ /*
+ * Scope the handler
+ */
+ public final void nextScope(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response)
+ throws IOException, ServletException
+ {
+ // this method has been manually inlined in several locations, but
+ // is called protected by an if(never()), so your IDE can find those
+ // locations if this code is changed.
+ if (_nextScope!=null)
+ _nextScope.doScope(target,baseRequest,request, response);
+ else if (_outerScope!=null)
+ _outerScope.doHandle(target,baseRequest,request, response);
+ else
+ doHandle(target,baseRequest,request, response);
+ }
+
+ /* ------------------------------------------------------------ */
+ /*
+ * Do the handler work within the scope.
+ */
+ public abstract void doHandle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response)
+ throws IOException, ServletException;
+
+ /* ------------------------------------------------------------ */
+ /*
+ * Do the handler work within the scope.
+ */
+ public final void nextHandle(String target, final Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException
+ {
+ // this method has been manually inlined in several locations, but
+ // is called protected by an if(never()), so your IDE can find those
+ // locations if this code is changed.
+ if (_nextScope!=null && _nextScope==_handler)
+ _nextScope.doHandle(target,baseRequest,request, response);
+ else if (_handler!=null)
+ _handler.handle(target,baseRequest, request, response);
+ }
+
+ /* ------------------------------------------------------------ */
+ protected boolean never()
+ {
+ return false;
+ }
+
+}
projects / gigi.git / blobdiff