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view src/org/eclipse/jetty/server/handler/ScopedHandler.java @ 873:220ad4853cda
remove StreamEndPoint
author | Franklin Schmidt <fschmidt@gmail.com> |
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date | Mon, 03 Oct 2016 20:03:50 -0600 |
parents | 3428c60d7cfc |
children |
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// // ======================================================================== // 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. 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>For example if Scoped handlers A, B & C were chained together, then * the calling order would be:<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:<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:<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= (ScopedHandler)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 (_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; } }