SpringBoot Jackson used to null values into a "" or the configuration does not return

The first embodiment: SpringBoot Jackson used to null values ​​were converted to ""

Preface: inevitably encounter null values ​​appear in the actual project, but we do not want to turn json NULL values ​​appear, but will be converted to NULL value "" The empty string. So, how should we deal with it? In SpringBoot, the configuration can create a new class.

@Configuration
public class JacksonConfig {

    @Bean
    @Primary
    @ConditionalOnMissingBean(ObjectMapper.class)
    public ObjectMapper jacksonObjectMapper(Jackson2ObjectMapperBuilder builder) {
        ObjectMapper objectMapper = builder.createXmlMapper(false).build();
        objectMapper.getSerializerProvider().setNullValueSerializer(new JsonSerializer<Object>() {
            @Override
            public void serialize(Object o, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException {
                jsonGenerator.writeString("");
            }
        });
        return objectMapper;
    }
}

Thus, when it came to a NULL value, it will be converted to form "" of.

The second way:

That is, yml configuration file:

spring:
  jackson:
    default-property-inclusion: non_null

The third way:

It is to use annotations in the entity classes:

@JsonInclude(JsonInclude.Include.NON_NULL)