upload file springboot Required request part 'file' is not present

This is how your request in Postman should look like:

My sample code:

application.properties

#max file and request size 
spring.http.multipart.max-file-size=10MB
spring.http.multipart.max-request-size=11MB

Main Application Class:

Application.java

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class Application {

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

Rest controller class:

import org.springframework.http.MediaType;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;


    @Controller
    @RequestMapping("/fileupload")
    public class MyRestController {

    @RequestMapping(value = "/file", method = RequestMethod.POST, produces = MediaType.APPLICATION_JSON_VALUE)
        public @ResponseBody String myService(@RequestParam("file") MultipartFile file,
                @RequestParam("id") String id) throws Exception {

    if (!file.isEmpty()) { 

           //your logic
                        }
return "some json";

                }
    }

pom.xml

//...

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.2.RELEASE</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>

....



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

//...

In your method you have specified like this
@RequestParam("file"). Hence it is expecting the key to be file. It is quite evident in the exception message. Use this name in the Key field in Postman when you upload file.
More information here integration test case and file upload