由于web中的文件不能直接通过url方式读取opencms的sites下的文件，所以必须绕个弯子解决。查阅了一下opencms的源代码，我的解决思路如下：

 

第一 拷贝方式：

 

   1.第一次访问时，根据opencms提供的接口，把文件从数据库读到java对象obj

   2.将obj对象拷贝到web中的对应目录

   3.将web中的对应目录的URL确定，即可直接调用。

   4.第二次及其以后访问时，根据对象obj的最后修改时间属性，确定是否需要重复1-3步骤。

参考源代码：
 

<!--  $Id: test.jsp,v  1.5   2006 / 08 / 11   04 : 59 : 31  davidye Exp $ -->
  <% @ page pageEncoding = " UTF-8 "   %>
<% @ page buffer = " none "   import = " org.opencms.util.*, org.teema.eeonline.exhibition.ExhibitionConstants,com.tblink.common.util.StringUtil,org.opencms.frontend.templateone.modules.*,javax.servlet.ServletOutputStream, org.opencms.file.*,java.util.*, java.io.*, org.opencms.frontend.templateone.* "   %>
<% @ taglib uri = " http://jakarta.apache.org/struts/tags-bean "  prefix = " bean " %>
<% @ taglib prefix = " cms "  uri = " http://www.opencms.org/taglib/cms "   %>
<% @ taglib prefix = " fmt "  uri = " http://java.sun.com/jstl/fmt "   %>
<% @ taglib prefix = " c "  uri = " http://java.sun.com/jstl/core "   %>
<% @ include file = " ../elements/common/common.jsp "   %>

<%!
private  String copyFile(CmsFile cmsFile){
     try {
         byte [] byteFile  =  cmsFile.getContents();
        String path  =  StringUtil.getRealPath(StringUtil. class , " WEB-INF " ,ExhibitionConstants.EXHIBITION_FLASH_DIRECTIONARY);
        RandomAccessFile rf = new  RandomAccessFile(path  +  ExhibitionConstants.EXHIBITION_FLASH_NAME, " rw " ); 
        rf.write(byteFile); 
        rf.close();
         return  path.substring( 0 ,path.length() - 1 );
    }
     catch (Exception e)
    {
         return   "" ;
    }
}
%>

<%
String direct  =  ExhibitionConstants.EXHIBITION_FLASH_DIRECTIONARY  +  ExhibitionConstants.EXHIBITION_FLASH_NAME;
String flashUrl  =   "" ;
try {
CmsFile cmsFile  =  __cmsJSP.getCmsObject().readFile(direct);
long  l  =  cmsFile.getDateLastModified();
String lstr  =  (String)application.getAttribute(ExhibitionConstants.APPLICATION_FLASH_DATE_INDEX);
flashUrl  =  (String)application.getAttribute(ExhibitionConstants.APPLICATION_FLASH_URL_INDEX);

if (lstr == null   ||   ! StringUtil.isNums(lstr)){
    direct  =  copyFile(cmsFile);
} else   if (Long.parseLong(lstr) == l){
     if (flashUrl == null ){
        direct  =  copyFile(cmsFile);
    }
} else {
      direct  =  copyFile(cmsFile);
}
flashUrl  =   request.getContextPath()  +  ExhibitionConstants.EXHIBITION_FLASH_DIRECTIONARY  +  ExhibitionConstants.EXHIBITION_FLASH_NAME;
application.setAttribute(ExhibitionConstants.APPLICATION_FLASH_DATE_INDEX,lstr);
application.setAttribute(ExhibitionConstants.APPLICATION_FLASH_URL_INDEX,flashUrl);

}
catch (Exception e)
{
    out.println(e); 
}
%>

< object classid = " clsid:D27CDB6E-AE6D-11cf-96B8-444553540000 "  codebase = " http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=6,0,29,0 "  width = " 760 "  height = " 266 " >
        < param name = " movie "  value = " <%=flashUrl%> " >
        < param name = " quality "  value = " high " >
        < embed src = " <%=flashUrl%> "  quality = " high "  pluginspage = " http://www.macromedia.com/go/getflashplayer "  type = " application/x-shockwave-flash "  width = " 760 "  height = " 266 " ></ embed >
</ object >