Aggregation聚合查询

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需求：在订单表中，根据buyerNick分组，统计每个buyerNick的电话、地址、支付总金额以及总商品数，返回结果是CustomerDetail。

public <T> List<T> findAggregateList(Query query,String userNickName, Aggregation aggregation,Class<T> clazz) {
    AggregationResults<T> aggregate = this.mongoTemplate.aggregate(aggregation, collectionName, clazz);
    List<T> customerDetails = aggregate.getMappedResults();
    return customerDetails;
Trade表：
public class TradeInfo{
    private String tid;//订单id
    private Double payment;//支付金额
    private String buyerNick;//买家昵称
    private String address;//地址
    private String mobile;//手机号
    private Long num;//购买商品数量
    private List<order> orders;子订单
CustomerDetail：
public class CustomerDetail{
    private String buyerNick;//买家昵称
    private Double totalPayment;//订单金额
    private Integer orderNum;//订单数
    private Integer itemNum;//商品数
    private String address;//地址
聚合分组，先过滤字段为type=Constants.DataSetOpt.OPT_VIEW,通过dateSetId进行分组，并计算每组的个数，.first是需要显示的字段。
    //浏览分组
    private List<Document> flowGroup() {
        Criteria criteria = Criteria.where("type").is(Constants.DataSetOpt.OPT_VIEW);
        Aggregation agg = Aggregation.newAggregation(
                Aggregation.match(criteria),
                Aggregation.group("dataSetId")
                        .first("dataSetId").as("dataSetId")
                        .count()
                        .as("dataSetIdCount")
                        .first("dataSetType").as("dataSetType")
        AggregationResults<Document> result = mongoTemplate.aggregate(agg,Access.class ,Document.class);
        return result.getMappedResults();
也可以使用TypedAggregation的方式进行聚合分组，如下：
    @Test
    public void statTest(){
        TypedAggregation<Statistics> agg = Aggregation.newAggregation(Statistics.class,
                Aggregation.group("month")
                        .sum("totalVisit")
                        .as("sumTotalVisit")
                        .sum("totalDownload")
                        .as("sumTotalDownload"));
        AggregationResults<Document> result = mongoTemplate.aggregate(agg, Document.class);
//        return result.getMappedResults();
        result.getMappedResults().forEach(document -> System.out.println(document));
addToSet使用方法示例
addToSet：将符合的字段值添加到一个集合或数组中\
    private List<Document> groupCountryOfOrigin() {
        Aggregation agg = Aggregation.newAggregation(
            Aggregation.group("countryOfOrigin")
                .first("countryOfOrigin").as("countryOfOrigin")
                .addToSet("portEntry").as("portEntryList")
                .addToSet("province").as("provinceList")
                .addToSet("customName").as("customNameList")
        AggregationResults<Document> result = mongoTemplate.aggregate(agg,CertificationBatchInfo.class , Document.class);
        return result.getMappedResults();
聚合内如获取
        List<Object> list = Lists.newArrayList();
        List<Document> documents = groupCountryOfOrigin();
        for (Document document : documents) {
            Map<String, Object> map = Maps.newHashMap();
            String countryOfOrigin = document.getString("countryOfOrigin");
            //这个进口国流向过哪些口岸
            List<String> portEntryList = document.getList("portEntryList", String.class);
            //这个进口国流向过哪些省市
            List<String> provinceList = document.getList("provinceList", String.class);
            //这个进口国流向国内哪些种商品
            List<String> customNameList = document.getList("customNameList", String.class);
            map.put("countryOfOrigin",countryOfOrigin);
            map.put("portEntryList",portEntryList);