Java tutorial
/* * $Header: /home/cvs/jakarta-tomcat-jasper/jasper2/src/share/org/apache/jasper/runtime/JspFactoryImpl.java,v 1.4 2003/09/02 20:41:00 luehe Exp $ * $Revision: 1.4 $ * $Date: 2003/09/02 20:41:00 $ * * ==================================================================== * * The Apache Software License, Version 1.1 * * Copyright (c) 1999 The Apache Software Foundation. All rights * reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. 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For more * information on the Apache Software Foundation, please see * <http://www.apache.org/>. * */ package org.apache.jasper.runtime; import java.security.AccessController; import java.security.PrivilegedAction; import javax.servlet.Servlet; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; import javax.servlet.jsp.JspFactory; import javax.servlet.jsp.JspEngineInfo; import javax.servlet.jsp.PageContext; import org.apache.jasper.util.SimplePool; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /** * Implementation of JspFactory. * * @author Anil K. Vijendran */ public class JspFactoryImpl extends JspFactory { // Logger private static Log log = LogFactory.getLog(JspFactoryImpl.class); private static final String SPEC_VERSION = "2.0"; private static final boolean USE_POOL = true; private SimplePool pool = new SimplePool(100); public PageContext getPageContext(Servlet servlet, ServletRequest request, ServletResponse response, String errorPageURL, boolean needsSession, int bufferSize, boolean autoflush) { if (System.getSecurityManager() != null) { PrivilegedGetPageContext dp = new PrivilegedGetPageContext((JspFactoryImpl) this, servlet, request, response, errorPageURL, needsSession, bufferSize, autoflush); return (PageContext) AccessController.doPrivileged(dp); } else { return internalGetPageContext(servlet, request, response, errorPageURL, needsSession, bufferSize, autoflush); } } public void releasePageContext(PageContext pc) { if (pc == null) return; if (System.getSecurityManager() != null) { PrivilegedReleasePageContext dp = new PrivilegedReleasePageContext((JspFactoryImpl) this, pc); AccessController.doPrivileged(dp); } else { internalReleasePageContext(pc); } } public JspEngineInfo getEngineInfo() { return new JspEngineInfo() { public String getSpecificationVersion() { return SPEC_VERSION; } }; } private PageContext internalGetPageContext(Servlet servlet, ServletRequest request, ServletResponse response, String errorPageURL, boolean needsSession, int bufferSize, boolean autoflush) { try { PageContext pc; if (USE_POOL) { pc = (PageContext) pool.get(); if (pc == null) { pc = new PageContextImpl(this); } } else { pc = new PageContextImpl(this); } pc.initialize(servlet, request, response, errorPageURL, needsSession, bufferSize, autoflush); return pc; } catch (Throwable ex) { /* FIXME: need to do something reasonable here!! */ log.fatal("Exception initializing page context", ex); return null; } } private void internalReleasePageContext(PageContext pc) { pc.release(); if (USE_POOL && (pc instanceof PageContextImpl)) { pool.put(pc); } } private class PrivilegedGetPageContext implements PrivilegedAction { private JspFactoryImpl factory; private Servlet servlet; private ServletRequest request; private ServletResponse response; private String errorPageURL; private boolean needsSession; private int bufferSize; private boolean autoflush; PrivilegedGetPageContext(JspFactoryImpl factory, Servlet servlet, ServletRequest request, ServletResponse response, String errorPageURL, boolean needsSession, int bufferSize, boolean autoflush) { this.factory = factory; this.servlet = servlet; this.request = request; this.response = response; this.errorPageURL = errorPageURL; this.needsSession = needsSession; this.bufferSize = bufferSize; this.autoflush = autoflush; } public Object run() { return factory.internalGetPageContext(servlet, request, response, errorPageURL, needsSession, bufferSize, autoflush); } } private class PrivilegedReleasePageContext implements PrivilegedAction { private JspFactoryImpl factory; private PageContext pageContext; PrivilegedReleasePageContext(JspFactoryImpl factory, PageContext pageContext) { this.factory = factory; this.pageContext = pageContext; } public Object run() { factory.internalReleasePageContext(pageContext); return null; } } }