Spring Boot 文件上传下载

左手的ㄟ右手 2022-05-10 04:03 223阅读 0赞

### 示例【Spring Boot  文件上传下载】 ###

程序清单：/springboot2/src/main/resources/templates/register.html

<!DOCTYPE html>
    <html xmlns:th="http://www.thymeleaf.org">
    <head>
    <meta charset="UTF-8">
    <title>注册</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">Spring Boot文件上传</h3>
    		</div>
    	</div>
    	<div class="container">
    		<div class="row">
    			<div class="col-md-8">
    				<form action="upload" method="post" enctype="multipart/form-data">
    					<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" 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" type="file" name="head">
    						</div>
    					</div>
    					<div class="form-group">
    						<div class="col-md-4">
    							<button type="submit" class="btn btn-success">注册</button>
    						</div>
    					</div>
    				</form>
    			</div>
    		</div>
    	</div>
    </body>
    </html>

程序清单：/springboot2/src/main/resources/templates/userInfo.html

<!DOCTYPE html>
    <html xmlns:th="http://www.thymeleaf.org">
    <head>
    <meta charset="UTF-8">
    <title>用户信息</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">Spring Boot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>
    		<div class="panel-body">
    			<div class="table table-responsive">
    				<table class="table table-bordered" id="userTable">
    					<tbody class="text-center">
    						<tr>
    							<td><img th:src="@{'upload/'+${user.head.originalFilename}}" height="30"></td>
    							<td th:text="${user.userName}">用户名</td>
    							<td><a th:href="@{download(filename=${user.head.originalFilename })}">下载</a></td>
    						</tr>
    					</tbody>
    				</table>
    			</div>
    		</div>
    	</div>
    </body>
    </html>

程序清单：/springboot2/src/main/java/com/dwx/hello/User.java

package com.dwx.hello;
    import org.springframework.web.multipart.MultipartFile;
    public class User {
    	private String userName;
    	private MultipartFile head;
    	public String getUserName() {
    		return userName;
    	}
    	public void setUserName(String userName) {
    		this.userName = userName;
    	}
    	public MultipartFile getHead() {
    		return head;
    	}
    	public void setHead(MultipartFile head) {
    		this.head = head;
    	}
    }

程序清单：/springboot2/src/main/java/com/dwx/hello/UserController.java

package com.dwx.hello;
    import java.io.File;
    import java.io.IOException;
    import java.net.URLEncoder;
    import javax.servlet.http.HttpServletRequest;
    import org.apache.commons.io.FileUtils;
    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.RequestHeader;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestParam;
    @Controller
    public class UserController {
    	@RequestMapping("/registerForm")
    	public String registerForm() {
    		return "register";
    	}
    	@RequestMapping("/upload")
    	public String upload(HttpServletRequest request,
    			@ModelAttribute User user,Model model) throws IllegalStateException, IOException {
    		if(!user.getHead().isEmpty()) {
    			String path=request.getServletContext().getRealPath("/upload");
    			String fileName=user.getHead().getOriginalFilename();
    			File filePath=new File(path,fileName);
    			if(!filePath.getParentFile().exists()) {
    				filePath.getParentFile().mkdirs();
    			}
    			user.getHead().transferTo(new File(path+File.separator+fileName));
    			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));
    	 }
    }

运行Spring Boot项目，访问以下地址：[http://localhost:8080/registerForm][http_localhost_8080_registerForm]

![70][]

![70 1][]

[http_localhost_8080_registerForm]: http://localhost:8080/registerForm
[70]: /images/20220510/18aa935b710340bc80dedb84e840b2ed.png
[70 1]: /images/20220510/b131898261944f88985da7c6b3e8e327.png