将“动态参数”JSP传递给JSP

Question

有JSP文件upLoad.jsp和popup_Tree.jsp，当你点击页面upLoad.jsp上的ViewTree.jsp按钮(value="...")时，打开弹出的(ViewTree.jsp)，其中会显示一个目录树，你可以选择要保存该文件的文件夹。在弹出窗口中有一个按钮"Upload“。

有JSP文件upLoad.jsp

<form name="fupload" method="post" enctype="multipart/form-data">
Upload file: <input type="f" name="f[]" id="filename" multiple="true" />
<input type="submit" value="Upload" onClick="return buttonupload();"/>
<input type="button" value="..." onClick="top.popup_Show('/_additional/upload_Js/ViewTree', 300, 380);return false;void(0);"/>           
</form>
<% ...
String[] pathDir = request.getParameterValues("pathDir"); 
%>

popup_Tree.jsp

<% ...
String pathDir = getServletContext().getRealPath(dir);
%>
<form style="display:none;">
<input type="hidden" name="dirPatch" id="dirPatch" value="<%=pathDir%>"/>
</form>

我想传达将保存文件的路径(from popup_Tree.jsp to upLoad.jsp)

我这样做，传达了“文件夹的路径”的意思: popup_Tree.jsp -->

<% String pathDir = getServletContext().getRealPath(dir);%>
<form style="display:none;" name="f" metod="post" action= "/_additional/upload.jsp">
<input type="hidden" name="dirPatch" id="dirPatch" value="<%= pathDir %>"/>
</form>
<%
    request.setAttribute("dirPtch", pathDir);
        String strViewPage="/_additional/upload.jsp";
        RequestDispatcher dispatcher = request.getRequestDispatcher(strViewPage);
        if (dispatcher != null){
        dispatcher.forward(request, response);
        } 
%>

upLoad.jsp -->

<%
out.println(request.getAttribute("dirPtch"));
%>

但输出- Null

Answer 1

您正在发布一个隐藏的表单变量：

<input type="hidden" name="dirPatch" id="dirPatch" value="<%= pathDir %>"/>

因此，在upload.jsp上，您需要使用getParameter

<% out.println(request.getParameter("dirPtch")); %>

或者，您可以使用EL

${param.dirPtch}