后端接口向前端返回list中有重复对象出现$ref: "$.list[0]"

业务需求是有一个医院咨询师的标签表,需要关联咨询师ID,医院ID,和标签id ; 点击咨询师会显示这个咨询师关联的所有标签(标签ID和医院ID)简单的讲就是需要通过咨询师ID在同一张表中查出医院ID和标签ID查出来是一个list,并通过这两个ID去对应的表中查出数据,在service层中给list中每个实体类都赋上医院实体类和标签实体类.

出现的问题是list中有重复的实体类就会出现如下情况

通过百度找到的解决办法是json转换的问题.

package com.hykj.hospital.config;

import com.alibaba.fastjson.serializer.SerializerFeature;
import com.alibaba.fastjson.support.config.FastJsonConfig;
import com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.MediaType;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.StringHttpMessageConverter;
import org.springframework.web.servlet.config.annotation.ContentNegotiationConfigurer;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.List;

/**
 * file: CustomWebMvcConfigurerAdapter.java
 * Created by jiaobuchong on 12/23/15.
 */
@Configuration   //标注此文件为一个配置项，spring boot才会扫描到该配置。该注解类似于之前使用xml进行配置
public class CustomWebMvcConfigurerAdapter extends WebMvcConfigurerAdapter {


    @Autowired
    private MainInterceptor mainInterceptor;
    @Autowired
    private AdminInterceptor adminInterceptor;


    @Bean
    public HttpMessageConverter<String> responseBodyConverter() {
        StringHttpMessageConverter converter = new StringHttpMessageConverter(
                Charset.forName("UTF-8"));
        return converter;
    }


    @Override
    public void configureMessageConverters(
            List<HttpMessageConverter<?>> converters) {
        super.configureMessageConverters(converters);
        converters.add(responseBodyConverter());
        FastJsonHttpMessageConverter fastConverter = new FastJsonHttpMessageConverter();
        FastJsonConfig fastJsonConfig = new FastJsonConfig();
        fastJsonConfig.setSerializerFeatures(SerializerFeature.WriteMapNullValue,SerializerFeature.DisableCircularReferenceDetect);

        //处理中文乱码问题
        List<MediaType> fastMediaTypes = new ArrayList<>();
        fastMediaTypes.add(MediaType.APPLICATION_JSON_UTF8);
        fastConverter.setSupportedMediaTypes(fastMediaTypes);
        fastConverter.setFastJsonConfig(fastJsonConfig);
        converters.add(fastConverter);
    }

    @Override
    public void configureContentNegotiation(
            ContentNegotiationConfigurer configurer) {
        configurer.favorPathExtension(false);
    }

    @Override
    public void addInterceptors(InterceptorRegistry registry) {

        registry.addInterceptor(mainInterceptor).addPathPatterns("/**");  //对来自/user/** 这个链接来的请求进行拦截


        registry.addInterceptor(adminInterceptor).addPathPatterns("/admin/**");


    }


    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/files/**").addResourceLocations("file:"+Config.FilePath);
    }


}