Java tutorial
/* * Copyright (c) 1998-2012 Caucho Technology -- all rights reserved * * This file is part of Resin(R) Open Source * * Each copy or derived work must preserve the copyright notice and this * notice unmodified. * * Resin Open Source is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * Resin Open Source is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty * of NON-INFRINGEMENT. See the GNU General Public License for more * details. * * You should have received a copy of the GNU General Public License * along with Resin Open Source; if not, write to the * * Free Software Foundation, Inc. * 59 Temple Place, Suite 330 * Boston, MA 02111-1307 USA * * @author Scott Ferguson */ package org.ireland.jnetty.dispatch.servlet; import javax.annotation.PostConstruct; import javax.servlet.FilterChain; import javax.servlet.Servlet; import javax.servlet.ServletException; import org.ireland.jnetty.config.ConfigException; import org.ireland.jnetty.dispatch.FilterChainInvocation; import org.ireland.jnetty.webapp.WebApp; import java.util.ArrayList; import java.util.HashMap; import org.apache.commons.logging.LogFactory; import org.apache.commons.logging.Log; /** * Manages the servlets. * * ?Servlet\Manager * */ public class ServletManager { static final Log log = LogFactory.getLog(ServletManager.class.getName()); static final boolean debug = log.isDebugEnabled(); // <ServletName,ServletConfigImpl> private HashMap<String, ServletConfigImpl> _servlets = new HashMap<String, ServletConfigImpl>(); private ArrayList<ServletConfigImpl> _servletList = new ArrayList<ServletConfigImpl>(); private final WebApp _webApp; public ServletManager(WebApp webApp) { _webApp = webApp; } /** * Adds a servlet to the servlet manager. ????ServletConfig, */ public void addServlet(ServletConfigImpl config) throws ServletException { synchronized (_servlets) { ServletConfigImpl existingConfig = _servlets.get(config.getServletName()); if (existingConfig != null) //???ServletConfig { for (int i = _servletList.size() - 1; i >= 0; i--) { ServletConfigImpl oldConfig = _servletList.get(i); if (config.getServletName().equals(oldConfig.getServletName())) { _servletList.remove(i); break; } } } try { config.validateClass(false); } catch (ConfigException e) { throw e; } catch (Exception e) { if (debug) log.debug(e.toString(), e); else if (e instanceof ConfigException) log.debug(e.getMessage()); else log.debug(e.toString()); } _servlets.put(config.getServletName(), config); _servletList.add(config); } } /** * Returns ServletConfigImpl to the servlet manager. */ public ServletConfigImpl getServlet(String servletName) { return _servlets.get(servletName); } public HashMap<String, ServletConfigImpl> getServlets() { return _servlets; } /** * Initialize servlets that need starting at server start. */ @PostConstruct public void init() throws ServletException { ArrayList<ServletConfigImpl> loadOnStartup = new ArrayList<ServletConfigImpl>(); // ?loadOnStartupServlet,??? for (int j = 0; j < _servletList.size(); j++) { ServletConfigImpl config = _servletList.get(j); if (config.getLoadOnStartup() == Integer.MIN_VALUE) continue; int i = 0; for (; i < loadOnStartup.size(); i++) { ServletConfigImpl config2 = loadOnStartup.get(i); if (config.getLoadOnStartup() < config2.getLoadOnStartup()) { loadOnStartup.add(i, config); break; } } if (i == loadOnStartup.size()) loadOnStartup.add(config); } // ?? loadOnStartup Servlet for (int i = 0; i < loadOnStartup.size(); i++) { ServletConfigImpl config = loadOnStartup.get(i); try { config.getInstance(); } catch (ServletException e) { log.warn(e.toString(), e); } } } /** * Creates the servlet chain for the servlet. ?ServletNameInvocationFilterChain */ public FilterChain createServletChain(String servletName, FilterChainInvocation invocation) throws ServletException { ServletConfigImpl config = _servlets.get(servletName); if (config == null) { throw new ServletException(servletName + " is not a known servlet. Servlets must be defined by <servlet> before being used."); } if (invocation != null) { // XXX: namedDispatcher if (!config.isAsyncSupported()) invocation.clearAsyncSupported(); invocation.setMultipartConfig(config.getMultipartConfig()); } return config.createServletChain(); } /** * Creates the servlet chain for the servlet. ?ServletConfigImplInvocationFilterChain */ public FilterChain createServletChain(ServletConfigImpl config, FilterChainInvocation invocation) throws ServletException { if (config == null) { throw new ServletException(config.getName() + " is not a known servlet. Servlets must be defined by <servlet> before being used."); } if (invocation != null) { // XXX: namedDispatcher if (!config.isAsyncSupported()) invocation.clearAsyncSupported(); invocation.setMultipartConfig(config.getMultipartConfig()); } return config.createServletChain(); } /** * Instantiates a servlet given its configuration. * * @param servletName * the servlet * * @return the initialized servlet. */ public Servlet createServlet(String servletName) throws ServletException { ServletConfigImpl config = _servlets.get(servletName); if (config == null) { throw new ServletException(servletName + " : is not a known servlet. Servlets must be defined by <servlet> before being used."); } return config.getInstance(); } /** * Returns the servlet config. */ ServletConfigImpl getServletConfig(String servletName) { return _servlets.get(servletName); } public void destroy() { ArrayList<ServletConfigImpl> servletList; servletList = new ArrayList<ServletConfigImpl>(); if (_servletList != null) { synchronized (_servletList) { servletList.addAll(_servletList); } } for (int i = 0; i < servletList.size(); i++) { ServletConfigImpl config = servletList.get(i); try { config.close(); } catch (Throwable e) { log.debug(e.toString(), e); } } } }