/** * Licensed under the Artistic License; you may not use this file * except in compliance with the License. * You may obtain a copy of the License at * *      http://displaytag.sourceforge.net/license.html * * THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. */package org.displaytag.filter;import java.io.IOException;import java.io.OutputStream;import java.io.PrintWriter;import java.util.Map;import javax.servlet.ServletRequest;import javax.servlet.http.HttpServletResponse;import org.apache.commons.lang.StringUtils;import org.apache.commons.logging.Log;import org.apache.commons.logging.LogFactory;import org.displaytag.tags.TableTag;import org.displaytag.tags.TableTagParameters;/** * Actually writes out the content of the wrapped response. Used by the j2ee filter and the Spring interceptor * implementations. * @author Fabrizio Giustina * @version $Revision: 1081 $ ($Author: fgiust $) */public final class ExportDelegate{    /**     * logger.     */    private static Log log = LogFactory.getLog(ExportDelegate.class);    /**     * Don靦 instantiate.     */    private ExportDelegate()    {        // unused    }    /**     * Actually writes exported data. Extracts content from the Map stored in request with the     * <code>TableTag.FILTER_CONTENT_OVERRIDE_BODY</code> key.     * @param wrapper BufferedResponseWrapper implementation     * @param response HttpServletResponse     * @param request ServletRequest     * @throws IOException exception thrown by response writer/outputStream     */    protected static void writeExport(HttpServletResponse response, ServletRequest request,        BufferedResponseWrapper wrapper) throws IOException    {        if (wrapper.isOutRequested())        {            // data already written            log.debug("Filter operating in unbuffered mode. Everything done, exiting");            return;        }        // if you reach this point the PARAMETER_EXPORTING has been found, but the special header has never been set in        // response (this is the signal from table tag that it is going to write exported data)        log.debug("Filter operating in buffered mode. ");        Map bean = (Map) request.getAttribute(TableTag.FILTER_CONTENT_OVERRIDE_BODY);        if (log.isDebugEnabled())        {            log.debug(bean);        }        Object pageContent = bean.get(TableTagParameters.BEAN_BODY);        if (pageContent == null)        {            if (log.isDebugEnabled())            {                log.debug("Filter is enabled but exported content has not been found. Maybe an error occurred?");            }            response.setContentType(wrapper.getContentType());            PrintWriter out = response.getWriter();            out.write(wrapper.getContentAsString());            out.flush();            return;        }        // clear headers        if (!response.isCommitted())        {            response.reset();        }        String filename = (String) bean.get(TableTagParameters.BEAN_FILENAME);        String contentType = (String) bean.get(TableTagParameters.BEAN_CONTENTTYPE);        if (StringUtils.isNotBlank(filename))        {            response.setHeader("Content-Disposition", "attachment; filename=\"" + filename + "\"");        }        String characterEncoding = wrapper.getCharacterEncoding();        String wrappedContentType = wrapper.getContentType();        if (wrappedContentType != null && wrappedContentType.indexOf("charset") > -1)        {            // charset is already specified (see #921811)            characterEncoding = StringUtils.substringAfter(wrappedContentType, "charset=");        }        if (characterEncoding != null && contentType.indexOf("charset") == -1) //$NON-NLS-1$        {            contentType += "; charset=" + characterEncoding; //$NON-NLS-1$        }        response.setContentType(contentType);        if (pageContent instanceof String)        {            // text content            if (characterEncoding != null)            {                response.setContentLength(((String) pageContent).getBytes(characterEncoding).length);            }            else            {                response.setContentLength(((String) pageContent).getBytes().length);            }            PrintWriter out = response.getWriter();            out.write((String) pageContent);            out.flush();        }        else        {            // dealing with binary content            byte[] content = (byte[]) pageContent;            response.setContentLength(content.length);            OutputStream out = response.getOutputStream();            out.write(content);            out.flush();        }    }}