1. 文件上传实现流程

1.1. 依赖

<!-- SpringMVC -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-webmvc</artifactId>
    <version>${spring.version}</version>
</dependency>
<!-- 文件上传 -->
<dependency>
    <groupId>commons-fileupload</groupId>
    <artifactId>commons-fileupload</artifactId>
    <version>1.4</version>
</dependency>

1.2. 配置CommonsMultipartResolver

<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
    <property name="maxUploadSize" value="#{1024 * 1024 * 10}"/>
    <property name="defaultEncoding" value="utf-8"/>
</bean>

1.3. 处理文件上传请求

@Controller
public class HelloController {
    @PostMapping("/file/upload")
    public void fileUpload(MultipartFile file, HttpServletRequest request) {
        try {
            InputStream in = file.getInputStream();
            String filename = file.getOriginalFilename();
            System.out.println("filename = " + filename);
            // 复制到本地
            FileUtils.copyInputStreamToFile(in, new File("C:\\" + filename));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

1.4. 测试

Postman向发起请求：localhost:8080/file/upload

Headers设置 Content-Type为multipart/form-data
Body将选中数据格式为form-data，添加一对key-value，key为file，value选择文件类型，上传文件

2. 多文件同步上传

前面的步骤不改变，只要修改一下Controller

@PostMapping("/upload")
public void upload(MultipartFile[] file) {
    for (MultipartFile multipartFile : file) {
        if (!multipartFile.isEmpty()) {
            try {
                // 保存文件到本地
                multipartFile.transferTo(new File("C:\\" + multipartFile.getOriginalFilename()));
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}