springdata-mongoTemplate对mongodb去重分页操作

import org.springframework.data.mongodb.core.aggregation.Aggregation
import org.springframework.data.mongodb.core.mongoTemplate
Criteria criteria = new Criteria();
criteria.and("groupid").in(bean.getGroupId());
List<Order> orders = new ArrayList<Order>();
orders.add(new Order(Direction.ASC, "_id"));
Sort sort = new Sort(orders);
Aggregation agg = Aggregation.newAggregation(
Aggregation.match(criteria),  //查询条件
Aggregation.group("detail"),
Aggregation.sort(sort),
Aggregation.skip((fianlPageNum - 1) * bean.getPageSize()),//跳到第几个开始
Aggregation.limit(bean.getPageSize())//查出多少个数据
);

List<String> details = new ArrayList<String>();
AggregationResults<BasicDBObject> outputType=mongoTemplate.aggregate(agg,TABLE_GROUP_LIST, BasicDBObject.class);
for (Iterator<BasicDBObject> iterator = outputType.iterator(); iterator.hasNext();) {
DBObject obj =iterator.next();
details.add((String) obj.get("_id"));
}
注意：
Aggregation.skip((fianlPageNum - 1) * bean.getPageSize()),
Aggregation.limit(bean.getPageSize())
顺序不能颠倒