1、问题原因
使用FastJson 如果返回结果中有空的字段会过滤

2、问题解决

@Configuration
public class ConverterConfig {

    @Bean
    @Order(Integer.MIN_VALUE)
    public HttpMessageConverters fastJsonHttpMessageConverters() {
        FastJsonHttpMessageConverter fastConverter = new FastJsonHttpMessageConverter();
        FastJsonConfig fastJsonConfig = new FastJsonConfig();
        //SerializerFeature.WriteMapNullValue 增加可解决
        fastJsonConfig.setSerializerFeatures(SerializerFeature.PrettyFormat,SerializerFeature.WriteMapNullValue);
        fastConverter.setFastJsonConfig(fastJsonConfig);
        return new HttpMessageConverters(fastConverter);
    }
  }