Spring.servlet.multipart configuration does not take effect

1. If the interface request error is caused by nginx

Check the configuration in nginx:

http {
    client_max_body_size 100m;
}

or:

 location ^~ /aaa/ {

        client_max_body_size  100m;
        client_body_buffer_size 128k;

       } 

2. If it is caused by the interface

Tomcat is used as the web container

For example, for springboot 2.X or above, configure the following

spring:
  servlet:
    multipart:
      # Open configuration 
      enabled: true   
      # Upload file size limit
      max-request-size: 100MB
      max-file-size: 100MB

3. Why is it configured like this? The reasons are as follows:

MultipartProperties attribute class

@ConfigurationProperties(prefix = "spring.servlet.multipart", ignoreUnknownFields = false)
public class MultipartProperties {

spring Enable configuration switch

Is spring.servlet.multipart.enabled true?

MultipartAutoConfiguration

@AutoConfiguration
@ConditionalOnClass({ Servlet.class, StandardServletMultipartResolver.class, MultipartConfigElement.class })
@ConditionalOnProperty(prefix = "spring.servlet.multipart", name = "enabled", matchIfMissing = true)
@ConditionalOnWebApplication(type = Type.SERVLET)
@EnableConfigurationProperties(MultipartProperties.class)
public class MultipartAutoConfiguration {