文件发送方

1.OpenFeign默认不支持文件上传，需要通过引入Feign的扩展包来实现，添加依赖

文件上传方需要添加如下依赖：

        <dependency>
            <groupId>io.github.openfeign.form</groupId>
            <artifactId>feign-form</artifactId>
            <version>3.8.0</version>
        </dependency>
        <dependency>
            <groupId>io.github.openfeign.form</groupId>
            <artifactId>feign-form-spring</artifactId>
            <version>3.8.0</version>
        </dependency>
        <dependency>
            <groupId>commons-fileupload</groupId>
            <artifactId>commons-fileupload</artifactId>
            <version>1.3.3</version>
        </dependency>
    </dependencies>

并且添加如下配置类：

@Configuration
public class FeignConfiguration {

    @Autowired
    private ObjectFactory<HttpMessageConverters> messageConverters;

    @Bean
    public Encoder feignEncoder() {
        return new SpringFormEncoder(new SpringEncoder(messageConverters));
    }
}

person类：

@Data
public class Person {
    private String name;
    private Integer age;
}

测试页面：index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <form action="/hello/test" method="post" enctype="multipart/form-data">
        <input type="text" name="name">
        <input type="text" name="age">
        <input type="file" name="file">
        <br>
        <div>上传文件：<input type="file" name="file2" multiple="multiple"></div>
        <input type="submit" value="Submit">
    </form>
</body>
</html>

controller:

@RestController
@RequestMapping("/hello")
public class HelloController {

    @Autowired
    private Client2FeignService client2FeignService;

    @PostMapping("/test")
    public String test(@RequestParam(value = "file")MultipartFile file, @RequestParam(value = "file2")MultipartFile[] files,Person person) {
        return client2FeignService.test(file, files, person.getAge(), person.getName());
    }

}

Client2FeignService接口：

注意：

  • PostMapping注解的consumes要设置成MediaType.MULTIPART_FORM_DATA_VALUE，不然会直接报错
  • MultipartFile类型前面用@RequestPart注解修饰，不然文件会传输不过去
@FeignClient("client2")
public interface Client2FeignService {

    @PostMapping(value = "/hello/test",consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
    String test(@RequestPart(value = "file") MultipartFile file, @RequestPart(value = "file2")MultipartFile[] files,
                @RequestParam("age") Integer age, @RequestParam("name") String name);
}

文件接收方

controller:

@RestController
@RequestMapping("/hello")
public class HelloController {

    @PostMapping("/test")
    String test(@RequestPart(value = "file") MultipartFile file, @RequestPart(value = "file2")MultipartFile[] files,
                @RequestParam("age") Integer age, @RequestParam("name") String name) {
        System.out.println(age);
        System.out.println(name);
        System.out.println(file.getSize());
        for (MultipartFile multipartFile : files) {
            System.out.println(multipartFile.getSize());
        }
        return "ok";
    }

}

测试

我这里：file参数只有一个文件，file2参数我上传了两个文件

image-20210928161727743

查看文件接收方的输出：

image-20210928161831557

单文件、多文件和其他普通参数都可以发送。

那这里name和age为什么要拆开来传输，而不直接传输Person实体类呢？

因为使用Person会直接报错，我目前没有找到好的办法。

那有人会问，如果实体类有很多字段怎么办，一个一个拿出来作为方法参数传过去吗？

当然不用，直接文件发送方把实体类转成json字符串，然后接收方再反序列化回来不就行了吗。

补充-2022/03/07

openfeign同时传输文件和实体类：

文件发送方：

    @PostMapping("/test")
    public String test(@RequestParam(value = "file")MultipartFile file, @RequestParam(value = "file2")MultipartFile[] files,Person person) {
        return client2FeignService.test(file, files, person);
    }

@FeignClient("client2")
public interface Client2FeignService {
    @PostMapping(value = "/hello/test",consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
    String test(@RequestPart(value = "file") MultipartFile file, @RequestPart(value = "file2")MultipartFile[] files,
                @SpringQueryMap Person person);
}

文件接收方：

    @PostMapping("/test")
    String test(@RequestPart(value = "file") MultipartFile file, @RequestPart(value = "file2")MultipartFile[] files, Person person) {
        System.out.println(person);
        System.out.println(file.getSize());
        for (MultipartFile multipartFile : files) {
            System.out.println(multipartFile.getSize());
        }
        return "ok";
    }

image-20220307195841331