springMVC實現文件上傳和下載
本文實例為大傢分享瞭springMVC實現文件上傳和下載的具體代碼，供大傢參考，具體內容如下
1準備工作
web.xml文件導入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>
前端測試頁面
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>$Title$</title>
</head>
<body>
<%-- 必須將表單的method設置為POST--%>
<%-- 設置enctype屬性為multipart/form-data，二進制傳遞數據--%>
<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" >點擊下載</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">
<!-- 自動掃描指定的包，下面所有註解類交給IOC容器管理，根據自己的項目掃描包 -->
<context:component-scan base-package="com.zky.controller"/>
<!-- 註解驅動 -->
<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>
<!-- 靜態資源過濾-->
<mvc:default-servlet-handler/>
<!-- 視圖解析器 -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"
id="internalResourceViewResolver">
<!-- 前綴 -->
<property name="prefix" value="/WEB-INF/jsp/" />
<!-- 後綴 -->
<property name="suffix" value=".jsp" />
</bean>
<!--文件上傳配置-->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<!-- 請求的編碼格式，必須和jSP的pageEncoding屬性一致，以便正確讀取表單的內容，默認為ISO-8859-1 -->
<property name="defaultEncoding" value="utf-8"/>
<!-- 上傳文件大小上限，單位為字節（10485760=10M） -->
<property name="maxUploadSize" value="10485760"/>
<property name="maxInMemorySize" value="40960"/>
</bean>
</beans>
2.文件上傳
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") 將name=file控件得到的文件封裝成CommonsMultipartFile 對象
//批量上傳CommonsMultipartFile則為數組即可
@RequestMapping("/upload")
public String fileUpload(@RequestParam("file") CommonsMultipartFile file , HttpServletRequest request) throws IOException {
//獲取文件名 : file.getOriginalFilename();
String uploadFileName = file.getOriginalFilename();
//如果文件名為空，直接回到首頁！
if ("".equals(uploadFileName)){
return "redirect:/index.jsp";
}
System.out.println("上傳文件名 : "+uploadFileName);
//上傳路徑保存設置
String path = request.getServletContext().getRealPath("/upload");
//如果路徑不存在，創建一個
File realPath = new File(path);
if (!realPath.exists()){
realPath.mkdir();
}
System.out.println("上傳文件保存地址："+realPath);
InputStream is = file.getInputStream(); //文件輸入流
OutputStream os = new FileOutputStream(new File(realPath,uploadFileName)); //文件輸出流
//讀取寫出
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 來保存上傳的文件
/*
* 采用file.Transto 來保存上傳的文件
*/
@RequestMapping("/upload2")
public String fileUpload2(@RequestParam("file") CommonsMultipartFile file, HttpServletRequest request) throws IOException {
//上傳路徑保存設置
String path = request.getServletContext().getRealPath("/upload");
File realPath = new File(path);
if (!realPath.exists()){
realPath.mkdir();
}
//上傳文件地址
System.out.println("上傳文件保存地址："+realPath);
//通過CommonsMultipartFile的方法直接寫文件（註意這個時候）
file.transferTo(new File(realPath +"/"+ file.getOriginalFilename()));
return "redirect:/index.jsp";
}
3.文件下載
@RequestMapping(value="/download")
public String downloads(HttpServletResponse response , HttpServletRequest request) throws Exception{
//要下載的圖片地址，改為自己圖片路徑,我是下載在我的項目裡面的
String path = request.getServletContext().getRealPath("/upload");
//文件名
String fileName = "新建文本文檔.txt";
//1、設置response 響應頭
response.reset(); //設置頁面不緩存,清空buffer
response.setCharacterEncoding("UTF-8"); //字符編碼
response.setContentType("multipart/form-data"); //二進制傳輸數據
//設置響應頭
response.setHeader("Content-Disposition",
"attachment;fileName="+ URLEncoder.encode(fileName, "UTF-8"));
File file = new File(path,fileName);
//2、 讀取文件--輸入流
InputStream input=new FileInputStream(file);
//3、 寫出文件--輸出流
OutputStream out = response.getOutputStream();
byte[] buff =new byte[1024];
int index=0;
//4、執行 寫出操作
while((index= input.read(buff))!= -1){
out.write(buff, 0, index);
out.flush();
}
out.close();
input.close();
return null;
}
以上就是本文的全部內容，希望對大傢的學習有所幫助，也希望大傢多多支持WalkonNet。