Spring Boot教程(十三)：Spring Boot文件上传

Love The Way You Lie 2022-05-25 13:24 220阅读 0赞

> 分享一个零基础，通俗易懂，而且非常风趣幽默的[人工智能教程(如不能直接点击访问，请以“右键”->“在新标签页中打开链接”方式打开)][-]网站，网址：https://www.cbedai.net/gnailoug/

# 一、创建一个简单的包含WEB依赖的SpringBoot项目 #

`pom.xml`内容：

<dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    
    
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>jstl</artifactId>
    </dependency>
    <dependency>
        <groupId>org.apache.tomcat.embed</groupId>
        <artifactId>tomcat-embed-jasper</artifactId>
        
    </dependency>

# 二、配置文件上传的文件大小限制 #

`application.properties`配置文件添加：

# 上传文件总的最大值
    spring.servlet.multipart.max-request-size=10MB
    # 单个文件的最大值
    spring.servlet.multipart.max-file-size=10MB
    
    ## jsp
    spring.mvc.view.prefix=/WEB-INF/jsp/
    spring.mvc.view.suffix=.jsp

*  `spring.servlet.multipart.max-file-size`限制单个文件的最大值
 *  `spring.servlet.multipart.max-request-size`限制上传的多个文件的总大小

# 三、单文件上传示例 #

1、创建Controller控制类，内容如下：

package com.songguoliang.springboot.controller;
    
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.PostMapping;
    import org.springframework.web.bind.annotation.RequestParam;
    import org.springframework.web.bind.annotation.ResponseBody;
    import org.springframework.web.multipart.MultipartFile;
    import org.springframework.web.multipart.MultipartHttpServletRequest;
    
    import javax.servlet.http.HttpServletRequest;
    import java.io.File;
    import java.io.IOException;
    import java.util.List;
    
    /**
     * @Description
     * @Author sgl
     * @Date 2018-05-15 14:04
     */
    @Controller
    public class UploadController {
        private static final Logger LOGGER = LoggerFactory.getLogger(UploadController.class);
    
        @GetMapping("/upload")
        public String upload() {
            return "upload";
        }
    
        @PostMapping("/upload")
        @ResponseBody
        public String upload(@RequestParam("file") MultipartFile file) {
            if (file.isEmpty()) {
                return "上传失败，请选择文件";
            }
    
            String fileName = file.getOriginalFilename();
            String filePath = "/Users/itinypocket/workspace/temp/";
            File dest = new File(filePath + fileName);
            try {
                file.transferTo(dest);
                LOGGER.info("上传成功");
                return "上传成功";
            } catch (IOException e) {
                LOGGER.error(e.toString(), e);
            }
            return "上传失败！";
        }
    
        
    }

2、创建`upload.jsp`文件

只有一个表单，选择文件，form的`enctype`为`multipart/form-data`:

<%@ page contentType="text/html;charset=UTF-8" pageEncoding="UTF-8" %>
    <!DOCTYPE html>
    <html>
    <head>
        <meta http-equiv="Content-type" content="text/html; charset=UTF-8">
        <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"/>
        <title>单文件上传</title>
    </head>
    <body>
    <form method="post" action="/upload" enctype="multipart/form-data">
        <input type="file" name="file"><br>
        <input type="submit" value="提交">
    </form>
    </body>
    </html>

3、通过springboot插件启动项目，浏览器输入`http://localhost:8080/upload`：

![这里写图片描述][70]

选择文件点击提交按钮返回成功信息，我们上传的文件保存在`/Users/itinypocket/workspace/temp`路径下：

![这里写图片描述][70 1]

# 四、多文件上传 #

1、创建多文件上传的jsp页面，多文件上传页面只是比单文件上传多了file选择的input而已，`multiUpload.jsp`内容如下：

<%@ page contentType="text/html;charset=UTF-8" pageEncoding="UTF-8" %>
    <!DOCTYPE html>
    <html>
    <head>
        <meta http-equiv="Content-type" content="text/html; charset=UTF-8">
        <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"/>
        <title>多文件上传</title>
    </head>
    <body>
    <form method="post" action="/multiUpload" enctype="multipart/form-data">
        <input type="file" name="file"><br>
        <input type="file" name="file"><br>
        <input type="file" name="file"><br>
        <input type="submit" value="提交">
    </form>
    </body>
    </html>

2、在`UploadController`里添加多文件上传的方法

@GetMapping("/multiUpload")
    public String multiUpload() {
        return "multiUpload";
    }
    
    @PostMapping("/multiUpload")
    @ResponseBody
    public String multiUpload(HttpServletRequest request) {
        List<MultipartFile> files = ((MultipartHttpServletRequest) request).getFiles("file");
        String filePath = "/Users/itinypocket/workspace/temp/";
        for (int i = 0; i < files.size(); i++) {
            MultipartFile file = files.get(i);
            if (file.isEmpty()) {
                return "上传第" + (i++) + "个文件失败";
            }
            String fileName = file.getOriginalFilename();
    
            File dest = new File(filePath + fileName);
            try {
                file.transferTo(dest);
                LOGGER.info("第" + (i + 1) + "个文件上传成功");
            } catch (IOException e) {
                LOGGER.error(e.toString(), e);
                return "上传第" + (i++) + "个文件失败";
            }
        }
    
        return "上传成功";
    
    }

3、重启服务，浏览器输入`http://localhost:8080/multiUpload`:

![这里写图片描述][70 2]

4、然后选择要上传的文件，点击提交按钮，得到成功信息：

![这里写图片描述][70 3]

我们选择的三个文件已被成功上传到`/Users/itinypocket/workspace/temp`路径下。

源码：  
[github][]  
[码云][Link 1]

[-]: https://www.cbedai.net/gnailoug/
[70]: /images/20220525/041350a02fd8471fb9aa05c3d36f83da.png
[70 1]: /images/20220525/c0abedb9d6bf44658f2ab9af6998d69d.png
[70 2]: /images/20220525/95827ed2ef4b42629ba559c7e82505c2.png
[70 3]: /images/20220525/b00093985bd84ee4a51231821cb4826f.png
[github]: https://github.com/itinypocket/spring-boot-study/tree/master/spring-boot-upload
[Link 1]: https://gitee.com/itinypocket/spring-boot-study/tree/master/spring-boot-upload