文件上传
1，配置文件上传解析器
在springmvc-servlet.xml中配置
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<!-- 设置上传文件的最大尺寸为1MB -->
<property name="maxUploadSize">
<value>1048576</value>
</property>
</bean>
需要导入fileupload依赖包 io的包
com.springsource.org.apache.commons.fileupload-1.2.0.jar
com.springsource.org.apache.commons.io-1.4.0.jar
2，编写前端页面代码，使用form表单上传
<%--
Created by IntelliJ IDEA.
User: Administrator
Date: 2018/11/7
Time: 15:43
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>文件上传</title>
</head>
<body>
<form action="uploadFile" method="post" enctype="multipart/form-data">
<input type="file" name="file"><br>
<input type="submit" value="提交">
</form>
</body>
</html>
3，controller里面的代码，
一定使用MultipartFile file作为形参，能将前端传入的文件自动注入到该参数中。
@RequestMapping("/uploadFile")
public String uploadFile(MultipartFile file){
System.out.println(file.getContentType());//获取文件类型
System.out.println(file.getSize());//获取文件大小
System.out.println(file.getOriginalFilename());//获取文件原始名称
System.out.println(file.getName());//input的name
//把文件保存在指定路径(桌面)
try {
File desFile = new File("C:/Users/Administrator/Desktop/"+file.getOriginalFilename());
FileUtils.copyInputStreamToFile(file.getInputStream(),desFile);
} catch (IOException e) {
e.printStackTrace();
}
return "index";
}
4，使用ajax上传图片，动态显示在傍边的img标签中
ajax的特点：异步请求，局部刷新
前端加上jquary代码
<%--
Created by IntelliJ IDEA.
User: Administrator
Date: 2018/11/9
Time: 19:37
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
<script type="text/javascript" src="jq.js"></script>
<script type="text/javascript">
$(function(){
$("#file").change(function(){
var data = new FormData($("#form")[0]);
$.ajax({
type:"post",
url:"uploadFile1",
data:data,
cache:false,
processData:false,
contentType:false,
beforeSend:function(){
},
success:function(msg){
$("img").attr("src",msg);
},
error:function(){
}
});
});
});
</script>
</head>
<body>
<form method="post" enctype="multipart/form-data" id="form">
<input type="file" name="file" id="file"><img style="width: 100px;height: 100px"><br>
</form>
</body>
</html>
controller代码
@RequestMapping("/uploadFile1")
@ResponseBody//局部刷新
public String uploadFile1(MultipartFile file ,HttpServletRequest request){
//把文件保存在指定路径
String path = request.getServletContext().getRealPath("imgs");
File destFile = new File(path+"/"+file.getOriginalFilename());
try {
InputStream in = file.getInputStream();
FileUtils.copyInputStreamToFile(in,destFile);
} catch (IOException e) {
e.printStackTrace();
}
String msg = "imgs/"+file.getOriginalFilename();
return msg;
}
5，文件下载
@RequestMapping("/download")
@ResponseBody
public void download(HttpServletResponse response) throws Exception{
response.setHeader("content-Disposition","attachment；filename = a.jpg");
OutputStream out = response.getOutputStream();
FileInputStream in = new FileInputStream("D:\\file\\1.jpg");
IOUtils.copy(in,out);
in.close();
out.close();
}
直接访问/download就能下载文件，不过现在都不用这种方法下载了，大都使用html5的新特性下载文件。