Springboot2.x配置ObjectMapper日期格式化不生效的问题解决

@Configuration
public class JacksonConfig {
    @Primary
    @Bean
    public ObjectMapper objectMapper() {
        ObjectMapper objectMapper = new ObjectMapper();
        JavaTimeModule javaTimeModule = new JavaTimeModule();
        javaTimeModule.addDeserializer(LocalDateTime.class, new LocalDateTimeDeserializer(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
        javaTimeModule.addSerializer(LocalDateTime.class, new LocalDateTimeSerializer(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
        //省略LocalDate、LocalTime的配置
        objectMapper.registerModule(javaTimeModule);
        objectMapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
        objectMapper.setTimeZone(TimeZone.getTimeZone("Asia/Shanghai"));
        objectMapper.registerModule(javaTimeModule);
        return objectMapper;
    }
}
@EnableWebMvc
@Component
public class MyWebMvcConfig implements WebMvcConfigurer {
     //省略一些常用配置
}

@Override
    public void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
        for (HttpMessageConverter<?> converter : converters) {
            if (converter instanceof MappingJackson2HttpMessageConverter) {
                ((MappingJackson2HttpMessageConverter) converter).setObjectMapper(objectMapper);
                break;
            }
        }
    }