Spring Cloud微服务项目文件上传/下载

news2024/9/22 1:10:06

在现代的微服务架构中，文件上传与下载是常见的需求，尤其是在需要处理大量文件数据的系统中。Spring Cloud 提供了灵活的工具和组件，使得在微服务中实现文件上传和下载变得高效而简便。

本文博主将详细介绍如何在 Spring Cloud 微服务项目中实现文件上传和下载功能。

前置条件

在开始本文前，博主希望你已经初步创建了一个Spring Cloud微服务项目：Spring Cloud微服务项目创建请参考：Spring Cloud微服务项目搭建

1.添加依赖

在子模块的 pom.xml 中添加必要的依赖(博主这里是 order 模块)：

<!-- oder 模块 pom.xml 配置文件 -->

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

2.配置上传文件的大小限制

在 application.properties 或 application.yml 中配置文件上传的大小限制：

# application.properties 配置文件

spring.servlet.multipart.max-file-size=10MB
spring.servlet.multipart.max-request-size=10MB

或

# application.yml 配置文件

spring:
  servlet:
    multipart:
      max-file-size: 10MB
      max-request-size: 10MB

3.编写Service和Controller层

3.1.创建文件上传方法

博主这里将MyBati 跟 MyBatis-Plus 二者结合一起使用，详情请参考：Spring Cloud微服务项目集成MyBatis

@Service
public class OrderService extends ServiceImpl<OrderMapper, OrderInfoModel> {

    /**
     * 文件上传
     */
    public String uploadFile(MultipartFile file) {
        if (file.isEmpty()) {
            return "上传文件不能为空!";
        } else {
            try {
                // 创建目录
                String uploadDir = "files/";
                File dir = new File(uploadDir);
                if (!dir.exists()) {
                    boolean created = dir.mkdirs();
                    if (!created) {
                        return "Failed to create upload directory.";
                    }
                }

                // 获取文件名
                String fileName = file.getOriginalFilename();
                Path path = Paths.get(uploadDir + fileName);

                // 将文件保存到目标路径
                Files.write(path, file.getBytes());

                // 返回 文件存储路径
                return "http://localhost:8000/api/auth/files/" + fileName;
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
    }
}

3.2.编写文件上传接口

这里Swagger接口文档请参考：Spring Cloud微服务项目聚合Swagger文档

@RestController
@RequestMapping("/api/auth/order")
@Tag(name = "订单管理")
public class OrderController {

    private final OrderService orderService;

    @Autowired
    public OrderController(OrderService orderService) {
        this.orderService = orderService;
    }

    @PostMapping("/uploadFile")
    @Operation(summary = "文件上传", parameters = {
            @Parameter(
                    name = "Authorization",
                    description = "TOKEN",
                    in = ParameterIn.HEADER,
                    required = true,
                    schema = @Schema(type = "string")
            )
    })
    public String uploadFile(@RequestParam("file") MultipartFile file) {
        return orderService.uploadFile(file);
    }
}

3.3.创建文件下载方法

@Service
public class OrderService extends ServiceImpl<OrderMapper, OrderInfoModel> {

    /**
     * 文件上传
     */
    public String uploadFile(MultipartFile file) {
        if (file.isEmpty()) {
            return "上传文件不能为空!";
        } else {
            try {
                // 创建目录
                String uploadDir = "files/";
                File dir = new File(uploadDir);
                if (!dir.exists()) {
                    boolean created = dir.mkdirs();
                    if (!created) {
                        return "Failed to create upload directory.";
                    }
                }

                // 获取文件名
                String fileName = file.getOriginalFilename();
                Path path = Paths.get(uploadDir + fileName);

                // 将文件保存到目标路径
                Files.write(path, file.getBytes());

                // 返回 文件存储路径
                return "http://localhost:8000/api/auth/files/" + fileName;
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
    }

    /**
     * 文件下载
     */
    public ResponseEntity<Resource> downloadFile(String fileName) {
        try {
            // 构建文件路径
            Path filePath = fileStorageLocation.resolve(fileName).normalize();
            Resource resource = new UrlResource(filePath.toUri());

            // 检查文件是否存在
            if (!resource.exists()) {
                return ResponseEntity.notFound().build();
            }

            // 设置响应头，触发下载
            String contentType = "application/octet-stream"; // 默认的 MIME 类型
            return ResponseEntity.ok()
                    .contentType(org.springframework.http.MediaType.parseMediaType(contentType))
                    .header(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\"" + resource.getFilename() + "\"")
                    .body(resource);

        } catch (Exception e) {
            return ResponseEntity.status(500).build();
        }
}

3.4.创建文件下载接口

@RestController
@RequestMapping("/api/auth/order")
@Tag(name = "订单管理")
public class OrderController {

    private final OrderService orderService;

    @Autowired
    public OrderController(OrderService orderService) {
        this.orderService = orderService;
    }

    @PostMapping("/uploadFile")
    @Operation(summary = "文件上传", parameters = {
            @Parameter(
                    name = "Authorization",
                    description = "TOKEN",
                    in = ParameterIn.HEADER,
                    required = true,
                    schema = @Schema(type = "string")
            )
    })
    public String uploadFile(@RequestParam("file") MultipartFile file) {
        return orderService.uploadFile(file);
    }

    @GetMapping("/download/{fileName:.+}")
    @Operation(summary = "文件下载", parameters = {
            @Parameter(
                    name = "Authorization",
                    description = "TOKEN",
                    in = ParameterIn.HEADER,
                    required = true,
                    schema = @Schema(type = "string")
            )
    })
    public ResponseEntity<Resource> downloadFile(@PathVariable String fileName) {
        return orderService.downloadFile(fileName);
    }
}