LinkedHashMap和HashMap的区别实战

Map<String, List<RecommendationListBO>> hashMap = new LinkedHashMap<>();
/*包装结构*/
for(RecommendationListBO recommendationListBO : recommendationList){
    /*map中存在此id，将数据存放当前key的map中*/
    if(hashMap.containsKey(recommendationListBO.getInsurederName())){
        hashMap.get(recommendationListBO.getInsurederName()).add(recommendationListBO);
    }else{//map中不存在，新建key，用来存放数据
        List<RecommendationListBO> recommendationListBOList = new ArrayList<>();
        recommendationListBOList.add(recommendationListBO);
        hashMap.put(recommendationListBO.getInsurederName(), recommendationListBOList);
    }
}