cmsflexresponse.java

cms是开源的框架

/*
 * File   : $Source: /usr/local/cvs/opencms/src/org/opencms/flex/CmsFlexResponse.java,v $
 * Date   : $Date: 2006/03/27 14:52:35 $
 * Version: $Revision: 1.42 $
 *
 * This library is part of OpenCms -
 * the Open Source Content Mananagement System
 *
 * Copyright (c) 2005 Alkacon Software GmbH (http://www.alkacon.com)
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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. See the GNU
 * Lesser General Public License for more details.
 *
 * For further information about Alkacon Software GmbH, please see the
 * company website: http://www.alkacon.com
 *
 * For further information about OpenCms, please see the
 * project website: http://www.opencms.org
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package org.opencms.flex;

import org.opencms.main.CmsIllegalArgumentException;
import org.opencms.main.CmsLog;
import org.opencms.util.CmsDateUtil;
import org.opencms.util.CmsRequestUtil;

import java.io.BufferedWriter;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;

import org.apache.commons.logging.Log;

/**
 * Wrapper class for a HttpServletResponse, required in order to process JSPs from the OpenCms VFS.<p>
 *
 * This class wrapps the standard HttpServletResponse so that it's output can be delivered to
 * the CmsFlexCache.<p>
 *
 * @author  Alexander Kandzior 
 * 
 * @version $Revision: 1.42 $ 
 * 
 * @since 6.0.0 
 */
public class CmsFlexResponse extends HttpServletResponseWrapper {

    /**
     * Wrapped implementation of the ServletOutputStream.<p>
     * 
     * This implementation writes to an internal buffer and optionally to another 
     * output stream at the same time.
     * It should be fully transparent to the standard ServletOutputStream.<p>
     */
    private class CmsServletOutputStream extends ServletOutputStream {

        /** The optional output stream to write to. */
        private ServletOutputStream m_servletStream;

        /** The internal stream buffer. */
        private ByteArrayOutputStream m_stream;

        /**
         * Constructor that must be used if the stream should write 
         * only to a buffer.<p>
         */
        public CmsServletOutputStream() {

            m_servletStream = null;
            clear();
        }

        /**
         * Constructor that must be used if the stream should write 
         * to a buffer and to another stream at the same time.<p>
         *
         * @param servletStream The stream to write to
         */
        public CmsServletOutputStream(ServletOutputStream servletStream) {

            m_servletStream = servletStream;
            clear();
        }

        /**
         * Clears the buffer by initializing the buffer with a new stream.<p>
         */
        public void clear() {

            m_stream = new java.io.ByteArrayOutputStream(1024);
        }

        /**
         * @see java.io.OutputStream#close()
         */
        public void close() throws IOException {

            if (m_stream != null) {
                m_stream.close();
            }
            if (m_servletStream != null) {
                m_servletStream.close();
            }
            super.close();
        }

        /**
         * @see java.io.OutputStream#flush()
         */
        public void flush() throws IOException {

            if (LOG.isDebugEnabled()) {
                LOG.debug(Messages.get().getBundle().key(Messages.LOG_FLEXRESPONSE_FLUSHED_1, m_servletStream));
            }
            if (m_servletStream != null) {
                m_servletStream.flush();
            }
        }

        /**
         * Provides access to the bytes cached in the buffer.<p>
         *
         * @return the cached bytes from the buffer
         */
        public byte[] getBytes() {

            return m_stream.toByteArray();
        }

        /**
         * @see java.io.OutputStream#write(byte[], int, int)
         */
        public void write(byte[] b, int off, int len) throws IOException {

            m_stream.write(b, off, len);
            if (m_servletStream != null) {
                m_servletStream.write(b, off, len);
            }
        }

        /**
         * @see java.io.OutputStream#write(int)
         */
        public void write(int b) throws IOException {

            m_stream.write(b);
            if (m_servletStream != null) {
                m_servletStream.write(b);
            }
        }

        /**
         * Writes an array of bytes only to the included servlet stream,
         * not to the buffer.<p>
         *
         * @param b The bytes to write to the stream
         * @throws IOException In case the write() operation on the included servlet stream raises one
         */
        public void writeToServletStream(byte[] b) throws IOException {

            if (m_servletStream != null) {
                m_servletStream.write(b);
            }
        }
    }

    /** The cache delimiter char. */
    public static final char FLEX_CACHE_DELIMITER = (char)0;

    /** Static string to indicate a header is "set" in the header maps. */
    public static final String SET_HEADER = "[setHeader]";

    /** The log object for this class. */
    protected static final Log LOG = CmsLog.getLog(CmsFlexResponse.class);

    /** Map to save response headers belonging to a single include call in .*/
    private Map m_bufferHeaders;

    /** String to hold a buffered redirect target. */
    private String m_bufferRedirect;

    /** Byte array used for "cached leafs" optimization. */
    private byte[] m_cacheBytes;

    /** The cached entry that is constructed from this response. */
    private CmsFlexCacheEntry m_cachedEntry;

    /** Indicates if caching is required, will always be true if m_writeOnlyToBuffer is true. */
    private boolean m_cachingRequired;

    /** The CmsFlexController for this response. */
    private CmsFlexController m_controller;

    /** The encoding to use for the response. */
    private String m_encoding;

    /** Map to save all response headers (including sub-elements) in. */
    private Map m_headers;

    /** A list of include calls that origin from this page, i.e. these are sub elements of this element. */
    private List m_includeList;

    /** A list of parameters that belong to the include calls. */
    private List m_includeListParameters;

    /** Indicates if this element is currently in include mode, i.e. processing a sub-element. */
    private boolean m_includeMode;

    /** A list of results from the inclusions, needed because of JSP buffering. */
    private List m_includeResults;

    /** Flag to indicate if this is the top level element or an included sub - element. */
    private boolean m_isTopElement;

    /** The CmsFlexCacheKey for this response. */
    private CmsFlexCacheKey m_key;

    /** A special wrapper class for a ServletOutputStream. */
    private CmsFlexResponse.CmsServletOutputStream m_out;

    /** Indicates that parent stream is writing only in the buffer. */
    private boolean m_parentWritesOnlyToBuffer;

    /** The wrapped ServletResponse. */
    private HttpServletResponse m_res;

    /** Indicates if this response is suspended (probably because of a redirect). */
    private boolean m_suspended;

    /** State bit indicating whether content type has been set, type may only be set once according to spec. */
    private boolean m_typeSet;

    /** Indicates that the OutputStream m_out should write ONLY in the buffer. */
    private boolean m_writeOnlyToBuffer;

    /** A printwriter that writes in the m_out stream. */
    private java.io.PrintWriter m_writer;

    /**
     * Constructor for the CmsFlexResponse,
     * this variation one is usually used to wrap responses for further include calls in OpenCms.<p>
     *
     * @param res the CmsFlexResponse to wrap     
     * @param controller the controller to use
     */
    public CmsFlexResponse(HttpServletResponse res, CmsFlexController controller) {

        super(res);
        m_res = res;
        m_controller = controller;
        m_encoding = controller.getCurrentResponse().getEncoding();
        m_isTopElement = controller.getCurrentResponse().isTopElement();
        m_parentWritesOnlyToBuffer = controller.getCurrentResponse().hasIncludeList() && !controller.isForwardMode();
        setOnlyBuffering(m_parentWritesOnlyToBuffer);
        m_headers = new HashMap(16);
        m_bufferHeaders = new HashMap(8);
    }

    /** 
     * Constructor for the CmsFlexResponse,
     * this variation is usually used for the "top" response.<p>
     *
     * @param res the HttpServletResponse to wrap
     * @param controller the controller to use
     * @param streaming indicates if streaming should be enabled or not
     * @param isTopElement indicates if this is the top element of an include cascade
     */
    public CmsFlexResponse(
        HttpServletResponse res,
        CmsFlexController controller,
        boolean streaming,
        boolean isTopElement) {

        super(res);
        m_res = res;
        m_controller = controller;
        m_encoding = controller.getCmsObject().getRequestContext().getEncoding();
        m_isTopElement = isTopElement;
        m_parentWritesOnlyToBuffer = !streaming && !controller.isForwardMode();
        setOnlyBuffering(m_parentWritesOnlyToBuffer);
        m_headers = new HashMap(16);
        m_bufferHeaders = new HashMap(8);
    }

    /**
     * Process the headers stored in the provided map and add them to the response.<p>
     * 
     * @param headers the headers to add
     * @param res the resonse to add the headers to
     */
    public static void processHeaders(Map headers, HttpServletResponse res) {

        if (headers != null) {
            Iterator i = headers.keySet().iterator();
            while (i.hasNext()) {
                String key = (String)i.next();
                List l = (List)headers.get(key);
                for (int j = 0; j < l.size(); j++) {
                    if ((j == 0) && (((String)l.get(0)).startsWith(SET_HEADER))) {
                        String s = (String)l.get(0);
                        res.setHeader(key, s.substring(SET_HEADER.length()));
                    } else {
                        res.addHeader(key, (String)l.get(j));
                    }
                }
            }
        }
    }

    /**
     * Method overloaded from the standard HttpServletRequest API.<p>
     *
     * Cookies must be set directly as a header, otherwise they might not be set
     * in the super class.<p>
     *
     * @see javax.servlet.http.HttpServletResponseWrapper#addCookie(javax.servlet.http.Cookie)
     */
    public void addCookie(Cookie cookie) {

        if (cookie == null) {
            throw new CmsIllegalArgumentException(Messages.get().container(Messages.ERR_ADD_COOKIE_0));
        }

        StringBuffer header = new StringBuffer(128);

        // name and value
        header.append(cookie.getName());
        header.append('=');
        header.append(cookie.getValue());

        // add version 1 / RFC 2109 specific information
        if (cookie.getVersion() == 1) {
            header.append("; Version=1");

            // comment
            if (cookie.getComment() != null) {
                header.append("; Comment=");
                header.append(cookie.getComment());
            }
        }

        // domain
        if (cookie.getDomain() != null) {
            header.append("; Domain=");
            header.append(cookie.getDomain());
        }

        // max-age / expires
        if (cookie.getMaxAge() >= 0) {
            if (cookie.getVersion() == 0) {
                // old Netscape format
                header.append("; Expires=");
                long time;
                if (cookie.getMaxAge() == 0) {
                    time = 10000L;
                } else {
                    time = System.currentTimeMillis() + (cookie.getMaxAge() * 1000L);