本文实例为大家分享了springmvc实现文件上传和下载的具体代码，供大家参考，具体内容如下
1准备工作
web.xml文件导入dispatcherservlet，characterencodingfilter
<servlet>
<servlet-name>springmvc</servlet-name>
<servlet-class>org.springframework.web.servlet.dispatcherservlet</servlet-class>
<init-param>
<param-name>contextconfiglocation</param-name>
<param-value>classpath:applicationcontext.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>springmvc</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<filter>
<filter-name>encoding</filter-name>
<filter-class>org.springframework.web.filter.characterencodingfilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>utf-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>encoding</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
前端测试页面
<%@ page contenttype="text/html;charset=utf-8" language="java" %>
<html>
<head>
<title>$title$</title>
</head>
<body>
<%-- 必须将表单的method设置为post--%>
<%-- 设置enctype属性为multipart/form-data，二进制传递数据--%>
<form action="${pagecontext.request.contextpath}/upload2" enctype="multipart/form-data" method="post">
<input type="file" name="file"/>
<input type="submit" value="upload">
</form>
<br/>
<a href="${pagecontext.request.contextpath}/download" rel="external nofollow" >点击下载</a>
</body>
</html>
spring配置文件applicationcontext.xml
<?xml version="1.0" encoding="utf8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/xmlschema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemalocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
https://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/mvc
https://www.springframework.org/schema/mvc/spring-mvc.xsd">
<!-- 自动扫描指定的包，下面所有注解类交给ioc容器管理，根据自己的项目扫描包 -->
<context:component-scan base-package="com.zky.controller"/>
<!-- 注解驱动 -->
<mvc:annotation-driven>
<mvc:message-converters register-defaults="true">
<bean class="org.springframework.http.converter.stringhttpmessageconverter">
<constructor-arg value="utf-8"/>
</bean>
<bean class="org.springframework.http.converter.json.mappingjackson2httpmessageconverter">
<property name="objectmapper">
<bean class="org.springframework.http.converter.json.jackson2objectmapperfactorybean">
<property name="failonemptybeans" value="false"/>
</bean>
</property>
</bean>
</mvc:message-converters>
</mvc:annotation-driven>
<!-- 静态资源过滤-->
<mvc:default-servlet-handler/>
<!-- 视图解析器 -->
<bean class="org.springframework.web.servlet.view.internalresourceviewresolver"
id="internalresourceviewresolver">
<!-- 前缀 -->
<property name="prefix" value="/web-inf/jsp/" />
<!-- 后缀 -->
<property name="suffix" value=".jsp" />
</bean>
<!--文件上传配置-->
<bean id="multipartresolver" class="org.springframework.web.multipart.commons.commonsmultipartresolver">
<!-- 请求的编码格式，必须和jsp的pageencoding属性一致，以便正确读取表单的内容，默认为iso-8859-1 -->
<property name="defaultencoding" value="utf-8"/>
<!-- 上传文件大小上限，单位为字节（10485760=10m） -->
<property name="maxuploadsize" value="10485760"/>
<property name="maxinmemorysize" value="40960"/>
</bean>
</beans>
2.文件上传
controller
package com.zky.controller;
import org.springframework.stereotype.controller;
import org.springframework.web.bind.annotation.requestmapping;
import org.springframework.web.bind.annotation.requestparam;
import org.springframework.web.multipart.commons.commonsmultipartfile;
import javax.servlet.http.httpservletrequest;
import javax.servlet.http.httpservletresponse;
import java.io.*;
import java.net.urlencoder;
@controller
public class filecontroller {
//@requestparam("file") 将name=file控件得到的文件封装成commonsmultipartfile 对象
//批量上传commonsmultipartfile则为数组即可
@requestmapping("/upload")
public string fileupload(@requestparam("file") commonsmultipartfile file , httpservletrequest request) throws ioexception {
//获取文件名 : file.getoriginalfilename();
string uploadfilename = file.getoriginalfilename();
//如果文件名为空，直接回到首页！
if ("".equals(uploadfilename)){
return "redirect:/index.jsp";
}
system.out.println("上传文件名 : "+uploadfilename);
//上传路径保存设置
string path = request.getservletcontext().getrealpath("/upload");
//如果路径不存在，创建一个
file realpath = new file(path);
if (!realpath.exists()){
realpath.mkdir();
}
system.out.println("上传文件保存地址："+realpath);
inputstream is = file.getinputstream(); //文件输入流
outputstream os = new fileoutputstream(new file(realpath,uploadfilename)); //文件输出流
//读取写出
int len=0;
byte[] buffer = new byte[1024];
while ((len=is.read(buffer))!=-1){
os.write(buffer,0,len);
os.flush();
}
os.close();
is.close();
return "redirect:/index.jsp";
}
}
采用file.transto 来保存上传的文件
/*
* 采用file.transto 来保存上传的文件
*/
@requestmapping("/upload2")
public string fileupload2(@requestparam("file") commonsmultipartfile file, httpservletrequest request) throws ioexception {
//上传路径保存设置
string path = request.getservletcontext().getrealpath("/upload");
file realpath = new file(path);
if (!realpath.exists()){
realpath.mkdir();
}
//上传文件地址
system.out.println("上传文件保存地址："+realpath);
//通过commonsmultipartfile的方法直接写文件（注意这个时候）
file.transferto(new file(realpath +"/"+ file.getoriginalfilename()));
return "redirect:/index.jsp";
}
3.文件下载
@requestmapping(value="/download")
public string downloads(httpservletresponse response , httpservletrequest request) throws exception{
//要下载的图片地址，改为自己图片路径,我是下载在我的项目里面的
string path = request.getservletcontext().getrealpath("/upload");
//文件名
string filename = "新建文本文档.txt";
//1、设置response 响应头
response.reset(); //设置页面不缓存,清空buffer
response.setcharacterencoding("utf-8"); //字符编码
response.setcontenttype("multipart/form-data"); //二进制传输数据
//设置响应头
response.setheader("content-disposition",
"attachment;filename="+ urlencoder.encode(filename, "utf-8"));
file file = new file(path,filename);
//2、 读取文件--输入流
inputstream input=new fileinputstream(file);
//3、 写出文件--输出流
outputstream out = response.getoutputstream();
byte[] buff =new byte[1024];
int index=0;
//4、执行 写出操作
while((index= input.read(buff))!= -1){
out.write(buff, 0, index);
out.flush();
}
out.close();
input.close();
return null;
}
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