selvlet转发时报空指针异常


messagedescription The server encountered an internal error () that prevented it from fulfilling this request.exceptionorg.apache.jasper.JasperException: Exception in JSP: /templates/3g_web_portal/runtime/3Gtamplate/downSongFile.jsp:148145: <% if (forwardpage != null) {%>
146: <jsp:forward page="<%=forwardpage %>"/>
147: <% } else { %>
148: <jsp:forward page="<%=firstForward %>"/>
149: <% } %>
150: 
151: <!--页脚_START-->
Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:506)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:395)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
com.onewaveinc.dolphin.portal.service.servlet.DownLoadSongServlet.doPost(DownLoadSongServlet.java:85)
com.onewaveinc.dolphin.portal.service.servlet.DownLoadSongServlet.doGet(DownLoadSongServlet.java:38)
javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)root causejava.lang.NullPointerException
org.apache.jasper.runtime.PageContextImpl.getAbsolutePathRelativeToContext(PageContextImpl.java:588)
org.apache.jasper.runtime.PageContextImpl.doForward(PageContextImpl.java:681)
org.apache.jasper.runtime.PageContextImpl.forward(PageContextImpl.java:658)
org.apache.jsp.templates._3g_005fweb_005fportal.runtime._3Gtamplate.downSongFile_jsp._jspService(downSongFile_jsp.java:319)
dispatcher = request.getRequestDispatcher(proFilePath+"/downSongFile.jsp?s="+s+"&t="+t+"&u="+pageInfo.getUserId());
dispatcher.forward(request,response);