從我的JSF Portlet的Liferay顯示pdf的問題

Question

我用jsf-portlet使用liferay 5.2。

從頁面我想按一個按鈕來生成一個PDF。 在managedbean我建立pdf，我想在迴應中顯示它。

在ByteArrayOutputStream名爲outputStream我有我的JasperReport構建的PDF。

我寫：

PortletResponse portletResponse = (PortletResponse)externalCtx.getResponse(); 
    HttpServletResponse httpResponse = PortalUtil.getHttpServletResponse(portletResponse); 

    ServletOutputStream out = httpResponse.getOutputStream(); 
    String filename="Pdf" + System.currentTimeMillis()+".pdf"; 
    httpResponse.reset(); 

    httpResponse.setContentType("application/pdf"); 
    httpResponse.setHeader("Content-Disposition", "attachment; filename=\""+ filename + "\""); 
    httpResponse.setContentLength(outputStream.size()); 

    outputStream.writeTo(out); 

    out.flush(); 
    out.close(); 

我沒有看到任何輸出！在jboss日誌中我讀到：IllegaStateException ....

什麼是錯？

LOG

 11:03:19,716 INFO [STDOUT] 11:03:19,716 ERROR [IncludeTag] Current URL /web/organo-di-governo/datawarehouse?p_p_id=1_WAR_Portlet_Datawarehouse_INSTANCE_D7s7&p_p_lifecycle=1&p_p_state=normal&p_p_mode=view&p_p_col_id=column-2&p_p_col_count=1&_1_WAR_Portlet_Datawarehouse_INSTANCE_D7s7_com.sun.faces.portlet.VIEW_ID=%2Fview.xhtml&_1_WAR_Portlet_Datawarehouse_INSTANCE_D7s7_com.sun.faces.portlet.NAME_SPACE=_1_WAR_Portlet_Datawarehouse_INSTANCE_D7s7_ generates exception: null 
       11:03:19,717 INFO [STDOUT] 11:03:19,717 ERROR [IncludeTag] java.lang.IllegalStateException 
        at com.liferay.portal.servlet.filters.strip.StripResponse.getWriter(StripResponse.java:85) 
        at org.apache.jasper.runtime.JspWriterImpl.initOut(JspWriterImpl.java:125) 
        at org.apache.jasper.runtime.JspWriterImpl.flushBuffer(JspWriterImpl.java:118) 
        at org.apache.jasper.runtime.JspWriterImpl.write(JspWriterImpl.java:326) 
        at org.apache.jasper.runtime.JspWriterImpl.write(JspWriterImpl.java:342) 
        at org.apache.jasper.runtime.JspWriterImpl.print(JspWriterImpl.java:468) 
        at com.liferay.taglib.util.ThemeUtil.includeVM(ThemeUtil.java:208) 
        at com.liferay.taglib.util.ThemeUtil.include(ThemeUtil.java:68) 
        at com.liferay.taglib.util.IncludeTag.doEndTag(IncludeTag.java:59) 
        at org.apache.jsp.html.common.themes.portal_jsp._jspx_meth_liferay_002dtheme_005finclude_005f1(portal_jsp.java:816) 
        at org.apache.jsp.html.common.themes.portal_jsp._jspx_meth_c_005fotherwise_005f0(portal_jsp.java:788) 
        at org.apache.jsp.html.common.themes.portal_jsp._jspService(portal_jsp.java:724) 
        at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70) 
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:803) 
        at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:373) 
        at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:336) 
        at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265) 
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:803) 
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) 
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) 
       11:03:19,718 ERROR [[jsp]] Servlet.service() for servlet jsp threw exception 
       java.lang.IllegalStateException 



     11:03:19,719 ERROR [[Main Servlet]] Servlet.service() for servlet Main Servlet threw exception 
     java.lang.IllegalStateException 
      at com.liferay.portal.servlet.filters.strip.StripResponse.getWriter(StripResponse.java:85) 
      at org.apache.jasper.runtime.JspWriterImpl.initOut(JspWriterImpl.java:125) 
      at org.apache.jasper.runtime.JspWriterImpl.flushBuffer(JspWriterImpl.java:118) 



     11:03:19,722 INFO [STDOUT] 11:03:19,720 ERROR [OpenSSOFilter] org.apache.jasper.JasperException: java.lang.IllegalStateException 
     org.apache.jasper.JasperException: java.lang.IllegalStateException 
      at org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:521) 
      at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:409) 
      at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:336) 
      at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265) 




     11:03:19,722 INFO [STDOUT] n.internalDoFilter(ApplicationFilterChain.java:235) 
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) 
      at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96) 


     Caused by: java.lang.IllegalStateException 
      at com.liferay.portal.servlet.filters.strip.StripResponse.getWriter(StripResponse.java:85) 
      at org.apache.jasper.runtime.JspWriterImpl.initOut(JspWriterImpl.java:125) 
      at org.apache.jasper.runtime.JspWriterImpl.flushBuffer(JspWriterImpl.java:118) 

Answer 1

的唯一合適的方式來做到這一點是通過使用JSR-286規範的「資源」階段。目前在你的代碼中，你處於「RENDER」階段，它強制只允許「text/html」編碼。

在純JSP，標籤看起來是這樣的：

<portlet:resourceURL id="/super-cool.pdf" /> 

然後在您的portlet類需要實現的serveResource（ResourceRequest REQ，ResourceResponse水庫）方法和讀取調用的req.getResourceId（）方法ResourceRequest並行爲調用您的業務邏輯（創建您的PDF），然後將其寫入輸出流。

在JSF中，我不完全確定它是否被支持，這意味着唯一的方法是將任務委託給servlet調用。在JSF中查看是否實現了JSR-286資源處理。