在项目中，经常用到的一个功能就是文件的上传和下载，不过大多数情况下都是通用的工具类，自己写的情况较少，这里写个通过Spring框架和ajaxFileUpload插件实现上传的小功能，做个练习和记录。
首先配置下SpringMVC的配置文件，配置支持文件上传
<!-- 配置MultipartResolver 用于文件上传 使用spring的CommosMultipartResolver
说明：
p:defaultEncoding="UTF-8"：这里设置默认的文件编码为UTF-8，必须与用户JSP的默认编码一致；
p:maxUploadSize="5000000"：指定文件上传大小，单位为字节；
p:uploadTempDir="fileUpload/temp"：文件上传临时目录，上传完成后，就会将临时文件删除；
-->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"
p:defaultEncoding="UTF-8"
p:maxUploadSize="5000000"
p:uploadTempDir="fileUpload/temp"
>
</bean> 然后写个简单的JSP页面，为了方便绑定数据，引入Spring自带的Form表单标签，引入语句
<%@taglib uri="http://www.springframework.org/tags/form" prefix="form" %> Form表单实现一个简单的注册功能，虽然说美感不好，这里还是引用了下bootstrap做了个简单的排版。因为原版的file标签的格式无法调整，所有用了其他的小标签代替，然后用按钮去触发file标签
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
request.setAttribute("_path", path);
%>
<%@taglib uri="http://www.springframework.org/tags/form" prefix="form" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
<link rel="stylesheet" href="<%=basePath%>static/css/bootstrap.css"/>
<script type="text/javascript" src="<%=basePath%>static/js/jquery.min.js"></script>
<script type="text/javascript" src="<%=basePath%>static/js/ajaxfileupload.js"></script>
<script type="text/javascript" src="<%=basePath%>static/js/bootstrap.js"></script>
<script type="text/javascript" src="<%=basePath%>static/js/jquery.json-2.4.js" charset="UTF-8"></script>
<script type="text/javascript">
var path = "${_path}";
$(function(){
$("#clean").click(function(){
document.getElementById("user").reset();
$("#userName").attr("value","");
$("#password").attr("value","");
$("#name").attr("value","");
$("#sex").attr("value","");
$("#file").attr("value","");
});
$("#choose").click(function(){
$("#fileUpload").click();
});
$("#fileUpload").change(function(){
$("#file").attr("value",$("#fileUpload").val());
$.ajaxFileUpload({
type: "POST",
url: path+"/fileUpload.do",
data:{fileName:$("#fileUpload").val()},//要传到后台的参数，没有可以不写
secureuri : false,//是否启用安全提交，默认为false
fileElementId:'fileUpload',//文件选择框的id属性
dataType: 'json',//服务器返回的格式
async : false,
success: function(mes){
if(mes.message=="OK"){
alert("附件上传成功");
}
if(mes.message=="NG"){
alert("附件上传失败");
}
},
error: function (){
alert("附件上传失败");
}
});
});
});
</script>
</head>
<body>
<div class="container" style="width: 100%" >
<div> </div>
<div class="row">
<div class="col-lg-5 col-md-5 col-sm-5 col-xs-5"></div>
<div class="col-lg-1 col-md-1 col-sm-1 col-xs-1" >注册页面</div>
</div>
<div> </div>
<div class="row">
<form:form commandName="user" action="${_path }/register.do" method="post" enctype="multipart/form-data">
<div class="col-lg-4 col-md-4 col-sm-4 col-xs-4"></div>
<div class="col-lg-1 col-md-1 col-sm-1 col-xs-1" style="text-align:right">账号：</div>
<form:input path="userName" type = "text" value = "" class="input-large"/>
<div> </div>
<div class="col-lg-4 col-md-4 col-sm-4 col-xs-4"></div>
<div class="col-lg-1 col-md-1 col-sm-1 col-xs-1" style="text-align:right">密码：</div>
<form:input path="password" type = "password" class="input-large"/>
<div> </div>
<div class="col-lg-4 col-md-4 col-sm-4 col-xs-4"></div>
<div class="col-lg-1 col-md-1 col-sm-1 col-xs-1" style="text-align:right">姓名：</div>
<form:input path="name" type = "text" value = "" class="input-large"/>
<div> </div>
<div class="col-lg-4 col-md-4 col-sm-4 col-xs-4"></div>
<div class="col-lg-1 col-md-1 col-sm-1 col-xs-1" style="text-align:right">性别：</div>
<form:input path="sex" type = "text" value = "" class="input-large"/>
<div> </div>
<div class="col-lg-4 col-md-4 col-sm-4 col-xs-4"></div>
<div class="col-lg-1 col-md-1 col-sm-1 col-xs-1" style="text-align:right">附件：</div>
<input id = "fileUpload" name = "fileUpload" type = "file" style=" display: none">
<form:input type ="text" class="input-large" path= "file" />
<input id ="choose" type="button" value = "选择" class="btn btn-primary btn-xs"/>
<div> </div>
<div class="col-lg-4 col-md-4 col-sm-4 col-xs-4"></div>
<div class="col-lg-2 col-md-2 col-sm-2 col-xs-2" style="text-align:right">
<input id = "upload" type = "submit" value = "提交" class="btn btn-default btn-sm"/>
<input id ="clean" type="button" value = "清除" class="btn btn-default btn-sm"/>
</div>
</form:form>
</div>
</div>
</body>
</html>
后台页面控制器，因为用了SpringMVC的form表单，所以在渲染的时候模型中一定要有user这个对象，所以我们用控制器跳转页面
@RequestMapping("/Login.do")
public String Login(@ModelAttribute("user") User user, Model model){
System.out.println("进入");
user.setName("小明");
user.setSex("男");
user.setUserName("叶良辰");
model.addAttribute("user", user);
return "index";
}这里为了显示SpringMVC form的自动绑定功能，我给user对象设置了值，在JSP页面，如果form:input标签由path属性和user里的属性一样，会自动设置值
附件的js代码在上面的JSP页面中已经写好了，下面是后台控制的controller，因为我们配置了multipartResolver，所以form表单是设置了enctype=”multipart/form-data，后台一样能直接取出文本值
接受文本框内容的controller
@RequestMapping("/register.do")
public String register(@ModelAttribute("user") User user, Model model){
model.addAttribute("user", user);
System.out.println(user);
return "index";
}附件上传的controller
@RequestMapping("/fileUpload.do")
public @ResponseBody Message fileUpload(HttpServletRequest request,@RequestParam("fileUpload") MultipartFile file,
@RequestParam("fileName") String fileName,@ModelAttribute("user") User user,Model model,Message mes){
//简单判断文件是否为空
if(!file.isEmpty()){
try {
// 文件保存路径
String filePath = request.getSession().getServletContext().getRealPath("/") + "fileUpload/"
+ file.getOriginalFilename();
file.transferTo(new File(filePath));
mes.setMessage("OK");
} catch (Exception e) {
mes.setMessage("NG");
e.printStackTrace();
}
}
user.setFile(fileName);
System.out.println(fileName);
model.addAttribute("user", user);
System.out.println(user);
return mes;
}