MultipartFile上传/下载图片

文件上传

图片上传使用 jquery的来异步提交，

使用jQuery第三方插件 jquer.form.js，

jsp的orm表单中要有enctype="multipart/form-data"

1、引入jar

2、springmvc.xml加入

 <!-- 实现文件上传的配置  --><bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">   <property name="defaultEncoding" value="UTF-8"/>    <property name="maxUploadSize" value="5242880"/> </bean>

3、springmvc.xml加入读取路径的配置

<mvc:resources mapping="/imgs/**" location="imgs/"></mvc:resources>

4、前台

4-1：jsp

注册一个onchange事件 οnchange="change()"

<form id="form13" action="<%=context_path%>点击上传的路径" method="post" enctype="multipart/form-data">
选择文件:<input type="file" name="picfile" οnchange="change()">
<img width="100" height="100" id="allimg" />
<input type="submit" value="上传">
</form>

4-2：js

function change() {  var opts = {  url:contextpath+"/ep/jxexamine/master/pictureupload",  type: "post",  dataType: "json",                     success: function(data) {                     $("#allimg").attr("src","${pageContext.request.contextPath}"+data.url);                       }  };  $("#form13").ajaxSubmit(opts);  }

5.后台

@ResponseBody@RequestMapping(value="pictureupload")public void uploadImg(@RequestParam MultipartFile picfile,HttpServletRequest request,HttpServletResponse response) {//编写图片上传的业务逻辑方法//获取图片名称String filename = picfile.getOriginalFilename();//获取图片扩展名String ext = filename.substring(filename.lastIndexOf(".")+1);//生成图片名称String imgName =UtilTools.getname();//自己写的一个获取字符串的方法作为图片名称//生成图片的存放在服务器的路径String path = "/imgs/"+imgName + "." + ext;//获取服务器的绝对路径进行保存图片String url = request.getSession().getServletContext().getRealPath("")+path;//图片上传try {InputStream in = picfile.getInputStream();OutputStream out = new FileOutputStream(new File(url));byte[] b = new byte[1024];int len;while((len =in.read(b))!= -1) {out.write(b, 0, len);}in.close();out.close();//把图片的路径使用json的格式进行返回JSONObject jo = new JSONObject();jo.put("path",path);jo.put("url", path);response.getWriter().write(jo.toString());} catch (IOException e) {e.printStackTrace();}}

图片上传 的另外一种方法@ResponseBody
@RequestMapping(value="/add.html",produces="text/html;charset=UTF-8",method=RequestMethod.POST)
public String add(@RequestParam("picpath1") MultipartFile picFile,Mobile mobile,
HttpServletRequest request,HttpSession session){mobile.setId(IDUtils.genImageName());mobile.setOntime(new Date());String child=picFile.getOriginalFilename();if (null!=child && !child.equals("")) {try {mobile.setPicpath(child);String path=session.getServletContext().getRealPath("/upload");File parent=new File(path);if (!parent.exists()) {parent.mkdir();}File descFile=new File(parent, child);picFile.transferTo(descFile);//文件上传} catch (Exception e) {e.printStackTrace();}}String path=request.getContextPath()+"/mobile/list.html";if (mobileService.insertSelective(mobile)) {return "<script>alert('添加成功');location.href='"+path+"'</script>";}return "<script>alert('添加成功');history.go(-1)</script>";
}

文件下载

前台js代码

 Util.ajax({url : contextpath + "/ep/data/mobile/list",param : {RESOURCE_ID : 此处为查询这款手机的id,mapping : "getMobilesById"},success : function(data) {if(data[0].picpath == undefined){window.location.href = contextpath + "/ep/base/data/error"; //返回到找不到文件的页面}else{window.location.href =contextpath+"/ep/data/mobile/download?path="+data[0].picpath+"&name="+data[0].mobiletype;}}});

后台代码

@RequestMapping(value = "download")
public String download(HttpServletRequest request,HttpServletResponse response) throws IOException{String file_path=request.getParameter("path");String ext = file_path.substring(file_path.lastIndexOf(".")+1);//这里获取服务器的绝对路径。如果不会用的话，用下面注释掉的方法就可以  //String root = getServletContext().getRealPath("/");   //用下面的方法前，需要把HttpServletRequest request当做一个参数传递到本方法中，直接使用即可  String root = request.getSession().getServletContext().getRealPath("/"); String file_name=request.getParameter("name");file_name=file_name+"."+ext; //如果文件名中有后缀 如.zip .jpg等  就不用这句话String filepath=root+file_path;    File file = new File(filepath);            InputStream fis = new BufferedInputStream(new FileInputStream(file));    byte[] buffer = new byte[fis.available()];    fis.read(buffer);    fis.close();    response.reset();    OutputStream toClient = new BufferedOutputStream(response.getOutputStream());    response.addHeader("Content-Disposition", "attachment;filename=" + new String(file_name.getBytes(), "ISO-8859-1"));    toClient.write(buffer);    toClient.flush();    toClient.close();    response.setContentType("application/octet-stream");    //这里的addHeader方法，如果报错，请使用下方注释掉的方法。  //response.addHeader("Content-Length", file.length());   //把第二个参数更改为String 类型即可  response.addHeader("Content-Length", String.valueOf(file.length()));  return null;    }