java文件上传

表单必须加

`<form name="form1" action="" method="post" **enctype="multipart/form-data"**></form>`//封装上传文件对象private File headImg;//封装上传文件类型的属性private String headImgContentType;//封装上传文件名的属性private String headImgFileName;//拿到保存文件的路径            String path = "/upload";            //根据相对路径获取绝对路径            String realPath = ServletActionContext.getServletContext().getRealPath(path);            System.out.println(realPath);            //使用uuid文件名            String uuid  = UUID.randomUUID().toString();            uuid=uuid.replace("-", "");            //拼接文件名            String filename ="/user/"+ uuid + headImgFileName.substring(headImgFileName.lastIndexOf("."));            //设置user头型的路径            user.setHeadImg(filename);            //上传文件            FileInputStream fis = new FileInputStream(headImg);            BufferedInputStream bis = new BufferedInputStream(fis);            FileOutputStream fos = new FileOutputStream(realPath+filename);            BufferedOutputStream bos = new BufferedOutputStream(fos);            byte[] bs = new byte[1024];            int len = 0;            while((len = bis.read(bs)) != -1){                bos.write(bs, 0, len);            }            bis.close();            bos.close();