springboot实现文件上传下载步骤

好的，针对您的问题，下面是SpringBoot实现文件上传下载的步骤：

1.引入相关依赖

<!-- 文件上传下载依赖 -->
<!-- 文件上传支持 -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

<!-- 文件上传下载支持 -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-tomcat</artifactId>
    <scope>provided</scope>
</dependency>

<!-- 文件上传下载支持 -->
<dependency>
    <groupId>org.apache.tomcat.embed</groupId>
    <artifactId>tomcat-embed-core</artifactId>
    <scope>provided</scope>
</dependency>
<dependency>
    <groupId>org.apache.tomcat.embed</groupId>
    <artifactId>tomcat-embed-logging-juli</artifactId>
    <scope>provided</scope>
</dependency>
<dependency>
    <groupId>org.apache.tomcat.embed</groupId>
    <artifactId>tomcat-embed-jasper</artifactId>
    <scope>provided</scope>
</dependency>

2.编写文件上传接口

@RestController
@RequestMapping("/file")
public class FileController {

    @PostMapping("/upload")
    public String uploadFile(@RequestParam("file") MultipartFile file) throws IOException {
        if (file.isEmpty()) {
            return "文件为空";
        }

        // 获取文件名
        String fileName = file.getOriginalFilename();
        // 获取文件后缀名
        String suffixName = fileName.substring(fileName.lastIndexOf("."));
        // 设置文件存储路径
        String filePath = "D:/upload/";
        // 重新生成文件名
        fileName = UUID.randomUUID() + suffixName;
        // 创建文件路径
        File dest = new File(filePath + fileName);
        // 存储文件
        file.transferTo(dest);
        return "上传成功";
    }
}

3.编写文件下载接口

@RestController
@RequestMapping("/file")
public class FileController {

    @GetMapping("/download")
    public ResponseEntity<byte[]> downloadFile() throws IOException {
        // 设置文件路径
        String filePath = "D:/upload/";
        // 设置文件名
        String fileName = "test.txt";
        // 获取文件对象
        File file = new File(filePath + fileName);
        // 创建字节输入流
        InputStream in = new FileInputStream(file);
        // 创建字节数组
        byte[] bytes = new byte[in.available()];
        // 将字节输入流读入字节数组
        in.read(bytes);
        // 创建HttpHeaders对象
        HttpHeaders headers = new HttpHeaders();
        // 设置下载文件名
        headers.setContentDispositionFormData("attachment", fileName);
        // 设置响应类型
        headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
        // 封装响应结果
        ResponseEntity<byte[]> responseEntity = new ResponseEntity<>(bytes, headers, HttpStatus.OK);
        return responseEntity;
    }
}

以上就是SpringBoot实现文件上传下载的步骤。如果您有其他问题需要咨询，欢迎继续提问。