distinctFieldName 就是去重字段，这个字段必须是keyword类型 不然会报错
//指定去重字段
CollapseBuilder collapseBuilder = new CollapseBuilder(distinctFieldName);
// 查询去重后的结果数量
CardinalityAggregationBuilder aggregationBuilder = AggregationBuilders.cardinality("distinct").field(distinctFieldName);
sourceBuilder.collapse(collapseBuilder);
sourceBuilder.aggregation(aggregationBuilder);
//去重查询要取另外的总数量
ParsedCardinality distinct = search.getAggregations().get("distinct");
Long total = NumberUtil.parseLong(distinct.getValueAsString());
SpringBoot 整合es(elasticsearch)使用elasticsearch-rest-high-level-client实现增删改查参考：https://www.cnblogs.com/pxblog/p/14808454.html
标签：collapseBuilder,distinct,distinctFieldName,查询,字段,elasticsearch,es From： https://www.cnblogs.com/pxblog/p/17048864.html