关于java:mongo随机获取N条数据

mongo 命令随机抽样

db.attachment_extract_status.aggregate( [ { $sample: { size: 500 }},{$match:{extract_status:1}} ] )

mongoTemplete随机抽样

@Testpublic void test_sample()  {    Aggregation aggregation =            Aggregation.newAggregation(                    Aggregation.match(Criteria.where("extract_status").is(1)), Aggregation.sample(1000)); AggregationResults<JSONObject> outputTypeCount =            mongoTemplate.aggregate(aggregation, "attachment_extract_status", JSONObject.class); for (Iterator<JSONObject> iterator = outputTypeCount.iterator(); iterator.hasNext(); ) {        System.out.println(iterator.next().getLong("content_id")); }}