使用flexpaper实现在线预览功能时 ，遇到的flash缓存问题的解放

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,FitPageOnLoad : false,ProgressiveLoading : true,localeChain: 'en_US'
		                }}
		        );
			}

<%@ 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();
%>

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,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,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",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",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();
%>