上传下载文件， 同时部署在webapps下， 而不是项目下，防止重新部署tomcat， 上传文件消失

前端上传

<a href='javascript:upload("+data[i].id+")' title='Upload Report'> <img src='${pageContext.request.contextPath}/FlatUI/img/edit2.png'   width=18px height=18px/></a>

js函数

function upload(id){
		 var winObj = window.open ("/portal/trip/toUpload?id="+id, "newwindow", "height=700, width=800, toolbar =no, menubar=no, scrollbars=no, resizable=no, location=no, status=no, top=50,left=1100");
		 var loop = setInterval(function() {
		 if(winObj.closed) {
				clearInterval(loop);
				 window.location.reload();
		 }
		}, 1);
 }

controller

@RequestMapping("/toUpload")
	public String toUpload(Long id, HttpServletRequest request){
　　　　　　　　　　request.setAttribute("id",id);
		return "/tripController/toUpload";
	}

前台toUpload.jsp

	   <form name="fileForm" action="/portal/trip/upload" method="post" enctype="multipart/form-data">
	    	<input type="hidden" name="id" id="id" value="${id }">
	   		<font size="2" face="Arial" color="#004779">Select: </font> <input type="file" name="file"  style="color:#95a5a6; padding-left:5px;border-radius:5px;  width:500px; height:28px; vertical-align:middle;">
	   		<input type="submit" value="Upload" style="color:#2c3e50;font-size:12px; font-weight:bold; border-radius:5px; vertical-align:middle;height:30px;  width:60px; ">

	   </form>

controller upload函数

@RequestMapping(value = "/upload", method = RequestMethod.POST)
	public String upload(@RequestParam("file") MultipartFile image, Long id,HttpServletRequest request, HttpServletResponse response) throws IllegalStateException, IOException{
		// 转型为MultipartHttpRequest
        MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request;
        // 根据前台的name名称得到上传的文件
        MultipartFile file = multipartRequest.getFile("file");
        // 获得文件名：
        String realFileName = file.getOriginalFilename();
        // 获取路径
        String ctxPath = request.getSession().getServletContext().getRealPath("/").substring(0, request.getSession().getServletContext().getRealPath("/").lastIndexOf(request.getContextPath().replace("/", "")));

        File dirPath = new File(ctxPath+File.separator+"upload"+File.separator+"trip"+File.separator);
        System.out.println("路径" + dirPath);
        /*String ctxPath = request.getSession().getServletContext()
          		 .getRealPath("/download/trip/")
                   + "/" ;
        System.out.println("路径" + ctxPath);
        // 创建文件
        File dirPath = new File(ctxPath);  */
        if (!dirPath.exists()) {
            dirPath.mkdir();
        }
        else{
            System.out.println("文件夹已经存在");
        }
        File uploadFile = new File(dirPath +File.separator+ realFileName);
        FileCopyUtils.copy(file.getBytes(), uploadFile);
        request.setAttribute("files", loadFiles(request));  

        tripService.updateById(id,"filename",realFileName);
        tripService.updateById(id,"ip",request.getRemoteHost());
        request.setAttribute("ip", request.getRemoteHost());
        //List<String> a = loadFiles(request);
		return "/tripController/success";
	}
	public List<String> loadFiles(HttpServletRequest request) {
        List<String> files = new ArrayList<String>();
        String ctxPath = request.getSession().getServletContext().getRealPath("/").substring(0, request.getSession().getServletContext().getRealPath("/").lastIndexOf(request.getContextPath().replace("/", "")));

        File file = new File(ctxPath+File.separator+"upload"+File.separator+"trip"+File.separator);
        if (file.exists()) {
            File[] fs = file.listFiles();
            String fname = null;
            for (File f : fs) {
                if (f.isFile()) {
                    fname=f.getName();
                    files.add(fname);
                }
            }
        }
        return files;
    }  
	@RequestMapping("/download/{fileName:.*}")
    public void download(@PathVariable("fileName") String fileName,
            HttpServletRequest request, HttpServletResponse response)
            throws Exception {
        response.setContentType("text/html;charset=utf-8");
        java.io.BufferedInputStream bis = null;
        java.io.BufferedOutputStream bos = null;
        String ctxPath = request.getSession().getServletContext().getRealPath("/").substring(0, request.getSession().getServletContext().getRealPath("/").lastIndexOf(request.getContextPath().replace("/", "")))+File.separator+"upload"+File.separator+"trip"+File.separator;
        String downLoadPath = ctxPath + fileName;
        System.out.println(downLoadPath);
        try {
            long fileLength = new File(downLoadPath).length();
            response.setContentType("application/x-msdownload;");
            response.setHeader("Content-disposition", "attachment; filename="
            		+java.net.URLEncoder.encode(fileName, "UTF-8").replace("+","%20"));
                   // + new String(fileName.getBytes("ISO8859-1"), "utf-8"));
            response.setHeader("Content-Length", String.valueOf(fileLength));
            bis = new BufferedInputStream(new FileInputStream(downLoadPath));
            bos = new BufferedOutputStream(response.getOutputStream());
            byte[] buff = new byte[2048];
            int bytesRead;
            while (-1 != (bytesRead = bis.read(buff, 0, buff.length))) {
                bos.write(buff, 0, bytesRead);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (bis != null)
                bis.close();
            if (bos != null)
                bos.close();
        }
    }

success.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
  <script type="text/javascript" src="../js/jquery-1.4.2.min.js"></script>
    <title></title>
  </head>
  <body>
	    <font size="4" face="Arial" color="#004779"><strong>Upload Success!</strong></font>
	    <hr>
	    <font size="2" face="Arial" color="#004779"><strong>File List:</strong>
	    <c:forEach var="month" items="${files}">
	        <li><a href="/portal/trip/download/${month}">${month}</a>     </li>
	    </c:forEach>
	    </font>
  		<hr><br>
<%-- 		 <a href="${pageContext.request.contextPath}/index.jsp">返回</a>  --%>
  </body>
</html>

下载

if(data[i].filename==null)
	str+="<td align='center' bordercolor='#DEDEDE'></td>";
else
	str+="<td align='center' bordercolor='#DEDEDE'><a href='/portal/trip/download/"+data[i].filename+"' title='Business Trip Materials Download'><img src='${pageContext.request.contextPath}/FlatUI/img/link.png' width=15px height=15px/></a></td>";