DataBufferLimitException: Exceeded limit on max bytes to buffer webflux error

This worked for me:

1. Create a @Bean in one of your configuration classes or the main SpringBootApplication class:

   @Bean
   public WebClient webClient() {
       final int size = 16 * 1024 * 1024;
       final ExchangeStrategies strategies = ExchangeStrategies.builder()
           .codecs(codecs -> codecs.defaultCodecs().maxInMemorySize(size))
           .build();
       return WebClient.builder()
           .exchangeStrategies(strategies)
           .build();
   }
   

2. Next, go to your desired class where you want to use the WebClient:

   @Service
   public class TestService {
   
       @Autowired
       private WebClient webClient;
   
       public void test() {
           String out = webClient
               .get()
               .uri("/my/api/endpoint")
               .retrieve()
               .bodyToMono(String.class)
               .block();
   
           System.out.println(out);
       }
   }
   

I suppose this issue is about adding a new spring.codec.max-in-memory-size configuration property in Spring Boot. Add it to the application.yml file like:

spring:
  codec:
    max-in-memory-size: 10MB

Set the maximum bytes (in megabytes) in your Spring Boot application.properties configuration file like below:

spring.codec.max-in-memory-size=20MB

i was getting this error for a simple RestController (i post a large json string).

here is how i successfully changed the maxInMemorySize

import org.springframework.context.annotation.Configuration;
import org.springframework.http.codec.ServerCodecConfigurer;
import org.springframework.web.reactive.config.ResourceHandlerRegistry;
import org.springframework.web.reactive.config.WebFluxConfigurer;

@Configuration
public class WebfluxConfig implements WebFluxConfigurer {

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {

        registry.addResourceHandler("/swagger-ui.html**")
            .addResourceLocations("classpath:/META-INF/resources/");

        registry.addResourceHandler("/webjars/**")
            .addResourceLocations("classpath:/META-INF/resources/webjars/");
    }

    @Override
    public void configureHttpMessageCodecs(ServerCodecConfigurer configurer) {
        configurer.defaultCodecs().maxInMemorySize(16 * 1024 * 1024);
    }
}

this was surprisingly hard to find