[size=large]第一步 导入静态类[/size]
[size=large]第二步 [/size]
import static org.springframework.data.mongodb.core.aggregation.Aggregation.group;
import static org.springframework.data.mongodb.core.aggregation.Aggregation.match;
import static org.springframework.data.mongodb.core.aggregation.Aggregation.newAggregation;
import static org.springframework.data.mongodb.core.aggregation.Aggregation.project;
import static org.springframework.data.mongodb.core.aggregation.Aggregation.sort;
[size=large]第二步 [/size]
Aggregation agg = newAggregation(
DeviceStatisticsInfo.class,
//project("companyName","deviceModel").and("count").previousOperation(),
group("companyName","deviceModel").count().as("count"),
sort(Sort.Direction.DESC, "count")
);
String collectionName = DeviceConstantTemplate.device_statistics_collection_name;
AggregationResults<DeviceStatisticsInfo> groupResults
= mongoTemplate.aggregate(agg,collectionName,DeviceStatisticsInfo.class);
List<DeviceStatisticsInfo> result = groupResults.getMappedResults();