Spring Boot支持文件上传

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>com.google.guava</groupId>
        <artifactId>guava</artifactId>
        <version>27.0.1-jre</version>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <optional>true</optional>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
</dependencies>

@Slf4j
@RestController
@SpringBootApplication
public class UploadApplication {

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

    @PostMapping("upload")
    public String upload(@RequestParam("file") MultipartFile file) {
        try {
            String s = CharStreams.toString(new InputStreamReader(file.getInputStream(), StandardCharsets.UTF_8));
        } catch (IOException e) {
            log.warn("fail to read file", file.getOriginalFilename(), e);
            return e.getMessage();
        }
        return "success";
    }
}

# The maximum size allowed for uploaded files, in bytes. If the size of any uploaded file is greater than this size, the web container will throw an exception (IllegalStateException). The default size is unlimited.
# 上传的文件的大小限制
spring.servlet.multipart.max-file-size=1KB
# The maximum size allowed for a multipart/form-data request, in bytes. The web container will throw an exception if the overall size of all uploaded files exceeds this threshold. The default size is unlimited.
# multipart/form-data请求的大小限制
spring.servlet.multipart.max-request-size=128KB

{
    "timestamp": "2019-04-28T12:39:26.437+0000",
    "status": 500,
    "error": "Internal Server Error",
    "message": "Maximum upload size exceeded; nested exception is java.lang.IllegalStateException: org.apache.tomcat.util.http.fileupload.FileUploadBase$FileSizeLimitExceededException: The field file exceeds its maximum permitted size of 1024 bytes.",
    "path": "/upload"
}