springboot RestController 配置fastjson，实体为null时不显示问题

客官°小女子只卖身不卖艺 2023-06-14 04:10 118阅读 0赞

Springboot 在和fastjson配合使用时，当返回实体为空时拦截不显示问题。在实际业务中，不管返回实体是否为空，都需要显示出来，如果为空则显示null。

解决方案，引入fastjson jar包

<dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>fastjson</artifactId>
                <version>1.2.22</version>
            </dependency>

添加配置ResultConfig：

package com.message.config;
    
    /**
     * @author :zoboy
     * @Description:
     * @ Date: Created in 2019-11-18 10:29
     */
    import com.alibaba.fastjson.serializer.SerializerFeature;
    import com.alibaba.fastjson.support.config.FastJsonConfig;
    import com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter;
    import org.springframework.boot.autoconfigure.http.HttpMessageConverters;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.http.MediaType;
    import org.springframework.http.converter.HttpMessageConverter;
    
    import java.util.ArrayList;
    import java.util.List;
    
    @Configuration
    public class ResultConfig {
    
        /*注入Bean : HttpMessageConverters，以支持fastjson*/
        @Bean
        public HttpMessageConverters fastJsonHttpMessageConverters() {
            FastJsonHttpMessageConverter fastConvert = new FastJsonHttpMessageConverter();
            FastJsonConfig fastJsonConfig = new FastJsonConfig();
            fastJsonConfig.setSerializerFeatures(SerializerFeature.PrettyFormat,
                    SerializerFeature.WriteNullStringAsEmpty,
                    SerializerFeature.WriteNullNumberAsZero,
                    SerializerFeature.WriteNullListAsEmpty,
                    SerializerFeature.WriteMapNullValue,
                    SerializerFeature.DisableCheckSpecialChar);
            fastJsonConfig.setDateFormat("yyyy-MM-dd hh:mm:ss");
            //处理中文乱码问题
            List<MediaType> fastMediaTypes = new ArrayList<>();
            fastMediaTypes.add(MediaType.APPLICATION_JSON_UTF8);
            fastConvert.setSupportedMediaTypes(fastMediaTypes);
            fastConvert.setFastJsonConfig(fastJsonConfig);
            return new HttpMessageConverters((HttpMessageConverter<?>) fastConvert);
        }
    }

结果：

{
      "code": "0",
      "message": "成功！",
      "data": null
    }

解决问题