Spring Boot文件上传与下载实战

雨点打透心脏的1/2处 2021-07-24 12:09 387阅读 0赞

**一  pom**

<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0  http://maven.apache.org/xsd/maven-4.0.0.xsd">
         <modelVersion>4.0.0</modelVersion>
         <groupId>org.fkit</groupId>
         <artifactId>fileuploadtest</artifactId>
         <version>0.0.1-SNAPSHOT</version>
         <packaging>jar</packaging>
         <name>fileuploadtest</name>
         <url>http://maven.apache.org</url>
         
         <parent>
               <groupId>org.springframework.boot</groupId>
               <artifactId>spring-boot-starter-parent</artifactId>
               <version>2.0.0.RELEASE</version>
               <relativePath />
         </parent>
         <properties>
               <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
               <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
               <java.version>1.8</java.version>
         </properties>
         <dependencies>
               
               <dependency>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-web</artifactId>
               </dependency>
               
               <dependency>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-thymeleaf</artifactId>
               </dependency>
               
               <dependency>
                    <groupId>commons-fileupload</groupId>
                    <artifactId>commons-fileupload</artifactId>
                    <version>1.3.3</version>
               </dependency>
               <dependency>
                    <groupId>junit</groupId>
                    <artifactId>junit</artifactId>
                    <scope>test</scope>
               </dependency>
         </dependencies>
    </project>

**二 启动类**

package org.fkit.fileuploadtest;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    
    
    //@SpringBootApplication指定这是一个 spring boot的应用程序.
    @SpringBootApplication
    public class App
    {
        public static void main( String[] args )
        {
            // SpringApplication 用于从main方法启动Spring应用的类。
            SpringApplication.run(App.class, args);
        }
    }

**三 实体类**

package org.fkit.fileuploadtest.domain;
    
    
    import java.io.Serializable;
    import org.springframework.web.multipart.MultipartFile;
    
    
    public class User implements Serializable{
        
        private static final long serialVersionUID = 1L;
        
        private String username;
        // 对应上传的headPortrait，类型为MultipartFile，上传文件会自动绑定到image属性当中
        private MultipartFile headPortrait;
        
        public User() {
            super();
        }
        
        public String getUsername() {
            return username;
        }
    
    
        public void setUsername(String username) {
            this.username = username;
        }
    
    
        public MultipartFile getHeadPortrait() {
            return headPortrait;
        }
        public void setHeadPortrait(MultipartFile headPortrait) {
            this.headPortrait = headPortrait;
        }
    }

**四 控制器**

package org.fkit.fileuploadtest.controller;
    
    
    import java.io.File;
    import java.net.URLEncoder;
    
    
    import javax.servlet.http.HttpServletRequest;
    
    
    import org.apache.commons.io.FileUtils;
    import org.fkit.fileuploadtest.domain.User;
    import org.springframework.http.MediaType;
    import org.springframework.http.ResponseEntity;
    import org.springframework.http.ResponseEntity.BodyBuilder;
    import org.springframework.stereotype.Controller;
    import org.springframework.ui.Model;
    import org.springframework.web.bind.annotation.ModelAttribute;
    import org.springframework.web.bind.annotation.PostMapping;
    import org.springframework.web.bind.annotation.RequestHeader;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestParam;
    import org.springframework.web.multipart.MultipartFile;
    
    
    @Controller
    public class FileUploadController {
    
    
        // 映射"/"请求
        @RequestMapping("/")
        public String index() {
            // 根据Thymeleaf默认模板，将返回resources/templates/index.html
            return "index";
        }
    
    
        @RequestMapping("/registerForm")
        public String registerForm() {
            return "registerForm";
        }
    
    
        // 上传文件会自动绑定到MultipartFile中
        @PostMapping(value = "/upload")
        public String upload(HttpServletRequest request, @RequestParam("description") String description,
                @RequestParam("file") MultipartFile file) throws Exception {
            // 接收参数description
            System.out.println("description = " + description);
            // 如果文件不为空，写入上传路径
            if (!file.isEmpty()) {
                // 上传文件路径
                String path = request.getServletContext().getRealPath("/upload/");
                System.out.println("path = " + path);
                // 上传文件名
                String filename = file.getOriginalFilename();
                File filepath = new File(path, filename);
                // 判断路径是否存在，如果不存在就创建一个
                if (!filepath.getParentFile().exists()) {
                    filepath.getParentFile().mkdirs();
                }
                // 将上传文件保存到一个目标文件当中
                file.transferTo(new File(path + File.separator + filename));
                return "success";
            } else {
                return "error";
            }
        }
    
    
        @RequestMapping(value = "/register")
        public String register(HttpServletRequest request, @ModelAttribute User user, Model model) throws Exception {
            // 接收参数username
            System.out.println("username = " + user.getUsername());
            // 如果文件不为空，写入上传路径
            if (!user.getHeadPortrait().isEmpty()) {
                // 上传文件路径
                String path = request.getServletContext().getRealPath("/upload/");
                System.out.println("path = " + path);
                // 上传文件名
                String filename = user.getHeadPortrait().getOriginalFilename();
                File filepath = new File(path, filename);
                // 判断路径是否存在，如果不存在就创建一个
                if (!filepath.getParentFile().exists()) {
                    filepath.getParentFile().mkdirs();
                }
                // 将上传文件保存到一个目标文件当中
                user.getHeadPortrait().transferTo(new File(path + File.separator + filename));
                // 将用户添加到model
                model.addAttribute("user", user);
                return "userInfo";
            } else {
                return "error";
            }
        }
    
        @RequestMapping(value = "/download")
        public ResponseEntity<byte[]> download(HttpServletRequest request, @RequestParam("filename") String filename,
                @RequestHeader("User-Agent") String userAgent, Model model) throws Exception {
            // 下载文件路径
            String path = request.getServletContext().getRealPath("/upload/");
            // 构建File
            File file = new File(path + File.separator + filename);
            // ok表示Http协议中的状态 200
            BodyBuilder builder = ResponseEntity.ok();
            // 内容长度
            builder.contentLength(file.length());
            // application/octet-stream ： 二进制流数据（最常见的文件下载）。
            builder.contentType(MediaType.APPLICATION_OCTET_STREAM);
            // 使用URLDecoder.decode对文件名进行解码
            filename = URLEncoder.encode(filename, "UTF-8");
            // 设置实际的响应文件名，告诉浏览器文件要用于【下载】、【保存】attachment 以附件形式
            // 不同的浏览器，处理方式不同，要根据浏览器版本进行区别判断
            if (userAgent.indexOf("MSIE") > 0) {
                // 如果是IE，只需要用UTF-8字符集进行URL编码即可
                builder.header("Content-Disposition", "attachment; filename=" + filename);
            } else {
                // 而FireFox、Chrome等浏览器，则需要说明编码的字符集
                // 注意filename后面有个*号，在UTF-8后面有两个单引号！
                builder.header("Content-Disposition", "attachment; filename*=UTF-8''" + filename);
            }
            return builder.body(FileUtils.readFileToByteArray(file));
        }
    }

**五 属性文件**

spring.thymeleaf.cache=false
    spring.http.multipart.maxFileSize=50MB
    spring.http.multipart.maxRequestSize=50MB

**六 模板**

1 error.html

<!DOCTYPE html>
    <html xmlns:th="http://www.thymeleaf.org">
    <head>
    <meta charset="UTF-8">
    <title>文件上传下载示例</title>
    <link rel="stylesheet" th:href="@{css/bootstrap.min.css}" />
    <link rel="stylesheet" th:href="@{css/bootstrap-theme.min.css}">
    <script type="text/javascript"  th:src="@{js/jquery-1.11.0.min.js}"></script>
    <script type="text/javascript"  th:src="@{js/bootstrap.min.js}"></script>
    </head>
    <body>
    <div class="panel panel-primary">
         
         <div class="panel-heading">
               
               <h3 class="panel-title">文件上传下载示例</h3>
         </div>
    </div>
    <div class="col-md-8">
         <div class="alert alert-danger" role="alert">文件上传失败!</div>
    </div>
    </body>
    </html>

2 index.html

<!DOCTYPE html>
    <html xmlns:th="http://www.thymeleaf.org">
    <head>
    <meta charset="UTF-8"></meta>
    <title>文件上传下载示例</title>
    <link rel="stylesheet" th:href="@{css/bootstrap.min.css}" />
    <link rel="stylesheet"  th:href="@{css/bootstrap-theme.min.css}"/>
    <script type="text/javascript"  th:src="@{js/jquery-1.11.0.min.js}"></script>
    <script type="text/javascript"  th:src="@{js/bootstrap.min.js}"></script>
    </head>
    <body>
    <div class="panel panel-primary">
         
         <div class="panel-heading">
               
               <h3 class="panel-title">文件上传下载示例：简单文件上传</h3>
         </div>
    </div>
    <div class="container">
         <div class="row">
               <div class="col-md-8">
                    <form class="form-horizontal" action="upload"  enctype="multipart/form-data" method="post">
                         <div class="form-group">
                               <div class="input-group col-md-4">
                                    <span  class="input-group-addon"><i class="glyphicon  glyphicon-pencil"></i></span>
                                    <input class="form-control"  placeholder="文件描述" type="text" name="description" />
                               </div>
                         </div>
                         <div class="form-group">
                               <div class="input-group col-md-4">
                                    <span  class="input-group-addon"><i class="glyphicon  glyphicon-search"></i></span>
                                    <input class="form-control"  placeholder="请选择文件" type="file" name="file"/>
                               </div>
                         </div>
                         <div class="form-group">
                               <div class="col-md-4">
                                    <div class="btn-group  btn-group-justified" >
                                           <div class="btn-group" >
                                             <button type="submit"  class="btn btn-success" id="submitbtn">
                                               <span  class="glyphicon glyphicon-share"></span> 文件上传</button>
                                           </div>
                                    </div>
                               </div>
                         </div>
                    </form>
               </div>
         </div>
    </div>
    </body>
    </html>

3 registerForm.html

<!DOCTYPE html>
    <html xmlns:th="http://www.thymeleaf.org">
    <head>
    <meta charset="UTF-8"></meta>
    <title>文件上传下载示例</title>
    <link rel="stylesheet" th:href="@{css/bootstrap.min.css}" />
    <link rel="stylesheet"  th:href="@{css/bootstrap-theme.min.css}"/>
    <script type="text/javascript"  th:src="@{js/jquery-1.11.0.min.js}"></script>
    <script type="text/javascript"  th:src="@{js/bootstrap.min.js}"></script>
    </head>
    <body>
    <div class="panel panel-primary">
         
         <div class="panel-heading">
               
               <h3 class="panel-title">文件上传下载示例：用户注册</h3>
         </div>
    </div>
    <div class="container">
         <div class="row">
               <div class="col-md-8">
                    <form class="form-horizontal" action="register"  enctype="multipart/form-data" method="post">
                         <div class="form-group">
                               <div class="input-group col-md-4">
                                    <span  class="input-group-addon"><i class="glyphicon  glyphicon-user"></i></span>
                                    <input class="form-control"  placeholder="用户名" type="text" name="username" />
                               </div>
                         </div>
                         <div class="form-group">
                               <div class="input-group col-md-4">
                                    <span  class="input-group-addon"><i class="glyphicon  glyphicon-search"></i></span>
                                    <input class="form-control"  placeholder="请选择头像" type="file" name="headPortrait"/>
                               </div>
                         </div>
                         <div class="form-group">
                               <div class="col-md-4">
                                    <div class="btn-group  btn-group-justified" >
                                           <div class="btn-group" >
                                             <button type="submit"  class="btn btn-success" id="submitbtn">
                                               <span  class="glyphicon glyphicon-share"></span> 注册</button>
                                           </div>
                                    </div>
                               </div>
                         </div>
                    </form>
               </div>
         </div>
    </div>
    </body>
    </html>

4 success.html

5 userInfo.html

<!DOCTYPE html>
    <html xmlns:th="http://www.thymeleaf.org">
    <head>
    <meta charset="UTF-8"></meta>
    <title>文件上传下载示例</title>
    <link rel="stylesheet" th:href="@{css/bootstrap.min.css}" />
    <link rel="stylesheet"  th:href="@{css/bootstrap-theme.min.css}"/>
    <script type="text/javascript"  th:src="@{js/jquery-1.11.0.min.js}"></script>
    <script type="text/javascript"  th:src="@{js/bootstrap.min.js}"></script>
    </head>
    <body>
    <div class="panel panel-primary">
         
         <div class="panel-heading">
               
               <h3 class="panel-title">文件上传下载示例：文件下载</h3>
         </div>
    </div>
    <div class="container">
               <div class="panel panel-primary">
                    
                    <div class="panel-heading">
                         
                         <h3 class="panel-title">用户信息列表</h3>
                    </div>
                    <div class="panel-body">
                         <div class="table table-responsive">
                               <table class="table table-bordered  table-hover" >
                                    <tbody class="text-center">
                                         <tr>
                                               <td><img  th:src="@{'upload/'+${user.headPortrait.originalFilename}}"  height="30"/></td>
                                               <td  th:text="${user.username}">用户名</td>
                                               <td >
                                               <a  th:href="@{download(filename=${user.headPortrait.originalFilename })}">下载头像</a>
                                               </td>
                                         </tr>
                                    </tbody>
                               </table>
                         </div>
                    </div>
               </div>
         </div>
    </body>
    </html>

**七 测试**

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70][]

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