文件上传

<%@ page contentType="text/html; charset=UTF-8" %>
<%@ page import="java.io.*"%>
<%@ page import="java.util.*"%>
<%@ page import="java.text.SimpleDateFormat" %>
<%@ page import="net.sf.json.JSONObject" %>
<%@ page import="org.apache.commons.fileupload.FileItemFactory" %>
<%@ page import="org.apache.commons.fileupload.disk.DiskFileItemFactory" %>
<%@ page import="org.apache.commons.fileupload.servlet.ServletFileUpload" %>
<%@ page import="org.apache.commons.fileupload.FileItem" %>
<%
    String rootPath;
    /*按照文件上传的时间，设置文件上传的地址*/
    SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");//设置日期格式

    String[] data = df.format(new Date()).split(" ");//将字符串转化成字符数组 
    String delemeter = System.getProperties().getProperty("file.separator"); //获取文件分隔符
    String dayindex = data[0].replace("-",delemeter);将yyyy-MM-dd转为 yyyy/MM/dd
    String timeindex = data[1].replace(":", "").replace(".", delemeter);将HH:mm:ss.SSS转化为HH/mm/ss/SSS
    String daypath = delemeter + "upload" +delemeter+ dayindex + delemeter + timeindex +delemeter;//上传文件的存储路径

    JSONObject json = new JSONObject();

    String realPath = request.getSession().getServletContext().getRealPath("/");// 获取的是Servlet容器对象，相当于tomcat容器了。getRealPath("/") 获取实际路径，“/”指代项目根目录，所以代码返回的是项目在容器中的实际发布运行的根路径
    String filetmpname = (String)request.getParameter("filename");//获取文件名字

    realPath = realPath.substring(0,realPath.lastIndexOf(delemeter));//截取从0到最后一个‘/’不包括‘/’的字符，
    //创建文件的保存目录
    rootPath = realPath + daypath;

    //创建保存路径的文件名
    String fileName = rootPath + filetmpname;

    // 验证上传内容了类型
    String contentType = request.getContentType();//Returns the MIME type of the body of the request, or null if the type is not known
    if ((contentType.indexOf("multipart/form-data") >= 0)){
        try {
            FileItemFactory factory = new DiskFileItemFactory();
            ServletFileUpload upload = new ServletFileUpload(factory);

            upload.setSizeMax(10*1024*1024);

            List<FileItem> list = upload.parseRequest(request);
            Iterator<FileItem> iter = list.iterator();
            while (iter.hasNext()) {
                FileItem item = iter.next();
                //item.isFormField()用来判断当前对象是否是file表单域的数据  如果返回值是true说明不是 就是普通表单域
                if (!item.isFormField()) {
                    File file = new File(rootPath);
                    if (!file.exists() && !file.isDirectory()) {//文件目录不存在创建目录
                        file.mkdirs();
                    }

                    File checkFile = new File(fileName);
                    if (checkFile.exists()) {
                        out.println("<exist>" + filetmpname + "文件已经存在.</exist>");
                    }
                    if (!checkFile.exists()) {
                        checkFile.createNewFile();
                        checkFile.setExecutable(true);
                        checkFile.setReadable(true);
                        checkFile.setWritable(true);
                    }

                    item.write(checkFile);
                    json.put("success", "上传文件成功");
                    json.put("filename", filetmpname);
                    json.put("path", daypath);
                    out.println(json);
                }
            }
        }catch (Exception e) {
            e.printStackTrace();
            json.put("success", "上传文件失败");
            out.println(json);
        }
    }
    else {
        json.put("success", "不是支持的文件");
        out.println(json);
    }
%>