想要在页面打开是判定一个session会话，这个session要等到跳转到服务器之后才能赋值。
但是明明我设定了判断是否为空，可是还是报错。
这是我的页面和服务器代码：
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<title>请填写上传表单</title>
<%
Object o = session.getAttribute("Error1");
if(!o.equals(null)||(!"".equals(o))){
String er = (String)o;
%>
操作失败，<%=er %>
<%
}
%>
关键字：
简要描述（10个字，可以不写）：
文章照片：
package com.hcpolic.servlet;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Iterator;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import com.hcpolic.entity.Artical;
import com.hcpolic.entity.User;
import com.hcpolic.rbac.Opreator;
import com.hcpolic.rbac.Permission;
import com.hcpolic.util.Tools;
import org.apache.commons.fileupload.disk.*;
import org.apache.commons.fileupload.servlet.*;
import org.apache.commons.fileupload.*;
public class UploadServlet extends HttpServlet {
/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doPost(request, response);
}
/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("UTF-8");
HttpSession session=request.getSession();
User us = (User)request.getSession().getAttribute("user");
String rem = (String)request.getAttribute("remark");
String key = (String)request.getAttribute("keyw");
String er = null;
Tools t = new Tools();
////////////////////////////////保存上传文件至指定文件夹
String savePath = "D:/upload/";
DiskFileItemFactory fac = new DiskFileItemFactory();
fac.setRepository(new File(savePath+"uploadtemp"));
ServletFileUpload upload = new ServletFileUpload(fac);
upload.setFileSizeMax(1048576);
try {
List<FileItem> it = upload.parseRequest(request);
Iterator<FileItem> iter = it.iterator();
while(iter.hasNext()){
FileItem item = iter.next();
String fieldName = item.getFieldName();
if(!item.isFormField()){
File saveFile = null;
InputStream input = null;
OutputStream output = null;
savePath = savePath + File.separator+String.valueOf(t.randomId(9,6))+"."+item.getName().split("\\.")[1];
input = item.getInputStream();
output = new FileOutputStream(new File(savePath));
byte data[] = new byte[512];
int temp = 0;
while((temp = input.read(data,0,512))!=-1){
output.write(data);
}
input.close();
output.close();
}
}
} catch (FileUploadException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
////////////////////////////////
///////////////////////////////抓取系统时间
String strDate = null;
SimpleDateFormat sf = new SimpleDateFormat("yyyy-MM-dd");
strDate = sf.format(new Date());
///////////////////////////////
Artical a = new Artical();
Permission per = new Permission();
Opreator o = new Opreator();
a.setId(us.getId().substring(4, 10)+String.valueOf(t.randomId(9,6)));
a.setKeyWords(key.trim());
a.setRemark(rem);
a.setImagePath(savePath);
a.setUpdateTime(strDate.trim());
boolean ret = o.isAdd(a, us);
if(ret){
response.sendRedirect("main.jsp");
}else{
er = "您的权限不够！！";
session.setAttribute("Error1", er);
response.sendRedirect("Upload.jsp");
}
}
}
