使用flexpaper实现在线预览功能时 ，遇到的flash缓存问题的解放方案

本项目使用的是本地目录映射为服务器相对路径，故预览页面时读取的flash与项目不再同一盘符中，若更改flash文件后，预览还是只显示之前的旧文件，一番搜索后找到了解决方案，flexpaper 的官方demo中，有一个和java相关的demo，其中给出了一些方法，整理后使用如下：

原本flexpaper调用时：

$('#documentViewer').FlexPaperViewer(                { config : {                    SWFFile : '<%=request.getContextPath()+"/"+swfFilePath%>',//服务器中映射为本地目录                    Scale : 1,                    ZoomTransition : 'easeOut',                    ZoomTime : 0.5,                    ZoomInterval : 0.2,                    FitPageOnLoad : true,                    FitWidthOnLoad : true,                    FullScreenAsMaxWindow : false,                    ProgressiveLoading : false,                    MinZoomSize : 0.2,                    MaxZoomSize : 5,                    SearchMatchAll : false,                    InitViewMode : 'Portrait',                    RenderingOrder : 'flash',                    StartAtPage : '',                    ViewModeToolsVisible : true,                    ZoomToolsVisible : true,                    NavToolsVisible : true,                    CursorToolsVisible : true,                    SearchToolsVisible : true,                    WMode : 'window',                    localeChain: 'en_US'                }}        );   

但一直出现缓存，解决方案：使用另一页面用文件流形式输出flash byte数组，在页面上直接显示，SWFFile 的值设为该页面，查看源码后发现，嵌入该属性时需整个URL编码，不然会无法显示。

function showSwf(swf){//console.log('show.jsp?swf='+encodeURI(swf)+'&temp='+Math.random());        $('#documentViewer').FlexPaperViewer(                { config : {                    SWFFile : encodeURIComponent('show.jsp?swf='+swf+'&temp='+Math.random()),                    Scale : 1,                    ZoomTransition : 'easeOut',                    ZoomTime : 0.5,                    ZoomInterval : 0.2,                    FitPageOnLoad : false,                    FitWidthOnLoad : true,                    FullScreenAsMaxWindow : false,                    ProgressiveLoading : true,                    MinZoomSize : 0.2,                    MaxZoomSize : 5,                    SearchMatchAll : false,                    InitViewMode : 'Portrait',                    RenderingOrder : 'flash',                    StartAtPage : '',                    ViewModeToolsVisible : true,                    ZoomToolsVisible : true,                    NavToolsVisible : true,                    CursorToolsVisible : true,                    SearchToolsVisible : true,                    WMode : 'window',                    localeChain: 'en_US'                }}        );}

显示页面：

<%@ page language="java" contentType="text/html; charset=UTF-8"    pageEncoding="UTF-8"%>    <%@ page import="java.io.*" %>    <%@ page import="com.wonders.attach.util.*" %><%!public byte[] file_get_contents(String file) {byte[] con = {0};if(file == null || file == "")return con;try {File f = new File(file);if(!f.isFile() || !f.canRead())return con;FileInputStream fstream = new FileInputStream(file);con = new byte[(int) f.length()];fstream.read(con);fstream.close();} catch (Exception e) {e.printStackTrace();}return con;}%><%String path = FileUpProperties.getValueByKey("file_path");String swf = (String)request.getParameter("swf");if(swf != null && swf.length()>0){swf = swf.replace("swf/","");}//System.out.println(swf); response.reset();//如果在weblogic底下同样要加上此句BufferedOutputStream outs = new BufferedOutputStream(response.getOutputStream());response.setContentType("application/x-shockwave-flash");response.setHeader("Accept-Ranges", "bytes");byte[] content = file_get_contents(path+swf);response.setContentLength(content.length);outs.write(content);outs.flush();outs.close();//out.clear();//out = pageContext.pushBody();%>

即可正常显示，解决缓存问题。

附上demo中，各文件格式输出方式：

<%@ page import="lib.*,java.io.*" %><%BufferedOutputStream outs = new BufferedOutputStream(response.getOutputStream());common conf = new common();String doc = request.getParameter("doc");String pdfdoc= doc;String pages= request.getParameter("page");String format= request.getParameter("format");String resolution= request.getParameter("resolution");String callback = request.getParameter("callback");if(doc == null)return;if(!doc.endsWith(".pdf")){pdfdoc = doc + ".pdf";}if(pages == null){pages = "";}if(format == null){format="swf";}String swfdoc= pdfdoc + ".swf";if("true".equals(conf.getConfig("splitmode", ""))){swfdoc = pdfdoc + "_" + pages + ".swf";}if(callback == null){callback = "";}String jsondoc= pdfdoc + ".js";if("true".equals(conf.getConfig("splitmode", ""))){jsondoc = pdfdoc + "_" + pages + ".js";}String pngdoc = pdfdoc + "_" + pages + ".png";String jpgcachedoc = pdfdoc + "_" + pages + "_res_" + resolution + ".jpg";String messages = "";String swfFilePath = conf.separate(conf.getConfig("path.swf", "")) + swfdoc;String pdfFilePath = conf.separate(conf.getConfig("path.pdf", "")) + pdfdoc;String pngFilePath = conf.separate(conf.getConfig("path.swf", "")) + pngdoc;String jpgCachePath = conf.separate(conf.getConfig("path.swf", "")) + jpgcachedoc;String jsonFilePath = conf.separate(conf.getConfig("path.swf", "")) + jsondoc;boolean validatedConfig = true;String error = "";if(!conf.is_dir(conf.getConfig("path.swf", ""))){error = "Error:Cannot find SWF output directory, please check your configuration file.";validatedConfig = false;}if(!conf.is_dir(conf.getConfig("path.pdf", ""))){error += "Error:Cannot find PDF output directory, please check your configuration file.";validatedConfig = false;}if(!validatedConfig){error += "Error:Cannot read directories set up in configuration file, please check your configuration.";}else if(!conf.validParams(pdfFilePath, pdfdoc, pages)){error += "Error:Incorrect file specified, please check your path.";}else{if("swf".equals(format) || "jpg".equals(format) || "png".equals(format) || "pdf".equals(format)){if(!conf.file_exists(swfFilePath)){pdf2swf pdfconv = new pdf2swf(request);messages = pdfconv.convert(pdfdoc, pages);}if("png".equals(format)||"jpg".equals(format)){if(conf.validParams(swfFilePath, swfdoc, pages)){if(!conf.file_exists(pngFilePath)){swfrender pngconv = new swfrender();pngconv.renderPage(pdfdoc, swfdoc, pages);}if("true".equals(conf.getConfig("allowcache", ""))){conf.setCacheHeaders(response);}if(conf.getConfig("allowcache") == null || "false".equals(conf.getConfig("allowcache", "")) || ("true".equals(conf.getConfig("allowcache", "")) && conf.endOrRespond(request, response))){if(resolution != null){response.setContentType("image/jpeg");outs.write(conf.file_get_contents(conf.generateImage(pngFilePath, jpgCachePath, resolution, "jpg")));}else if("jpg".equals(format)){    response.setContentType("image/jpeg");outs.write(conf.file_get_contents(conf.generateImage(pngFilePath, jpgCachePath, null, "jpg")));}else{response.setContentType("image/png");outs.write(conf.file_get_contents(pngFilePath));}}}else{if(messages.length() == 0 || "[OK]".equals(messages))messages = "[Incorrect file specified, please check your path]";}} else if("pdf".equals(format)){response.setContentType("application/pdf");outs.write(conf.file_get_contents(pdfFilePath));}if(conf.file_exists(swfFilePath)){if("swf".equals(format)){if("true".equals(conf.getConfig("allowcache", ""))){conf.setCacheHeaders(response);}if(conf.getConfig("allowcache") == null || "false".equals(conf.getConfig("allowcache", "")) || ("true".equals(conf.getConfig("allowcache", "")) && conf.endOrRespond(request,response))){response.setContentType("application/x-shockwave-flash");response.setHeader("Accept-Ranges", "bytes");byte[] content = conf.file_get_contents(swfFilePath);response.setContentLength(content.length);outs.write(content);}}}else{if(messages.length() == 0)messages = "[Cannot find SWF file. Please check your JSP configuration]";}}else if("json".equals(format) || "jsonp".equals(format)){if(!conf.file_exists(jsonFilePath)){pdf2json jsonconv = new pdf2json();messages = jsonconv.convert(pdfdoc, jsondoc, pages);}if(conf.file_exists(jsonFilePath)){if("true".equals(conf.getConfig("allowcache", ""))){conf.setCacheHeaders(response);}if(conf.getConfig("allowcache") == null || "false".equals(conf.getConfig("allowcache", "")) || ("true".equals(conf.getConfig("allowcache", "")) && conf.endOrRespond(request,response))){response.setContentType("text/javascript");if("json".equals(format)){outs.write(conf.file_get_contents(jsonFilePath));}if("jsonp".equals(format)){outs.write((callback + "(").getBytes());outs.write(conf.file_get_contents(jsonFilePath));outs.write((");").getBytes());}}}else{if(messages.length() == 0)messages = "[Cannot find JSON file. Please check your JSP configuration]";}}if(messages.length() > 0 && !"[OK]".equals(messages) && !"[Converted]".equals(messages) && !"png".equals(format)){outs.write(("Error:" + messages.substring(1,messages.length()-2)).getBytes());}}if(error.length() > 0)outs.write(error.getBytes());outs.flush();outs.close();out.clear();out = pageContext.pushBody();%>