monodb 聚合框架 Aggregation

前提：本人采用mongodb和spring整合的project

与SQL对照的操作

import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.stereotype.Service;

import com.mongodb.AggregationOutput;
import com.mongodb.BasicDBObject;
import com.mongodb.DB;
import com.mongodb.DBObject;

@Service
public class NetflowDao  {

          @Autowired
	  MongoTemplate mongoTemplate;

                                     public static void main(String[] args) {
				        	// 假设表中列有 _id  name age  score 
					         Map matchMap = new HashMap();
				        	 //where 条件 年龄大于12 
				        	 matchMap.put("age", new BasicDBObject("$gt", 12));
				        	 
					         Map groupMap = new HashMap();
					         groupMap.put("name","$name");
					         groupMap.put("age","$age");
					         
					         BasicDBObject   Basicgroup= new BasicDBObject();
					         
					         //分组条件
					         Basicgroup.put("_id", groupMap);
					         //计算总分
					         Basicgroup.put("totalscore", new BasicDBObject("$sum", "$score"));
					         
					         BasicDBObject group=new BasicDBObject("$group", Basicgroup);
					         
					         
					            //分页条件 每次查询返回条数
								BasicDBObject groupOptlimit = new BasicDBObject();
								groupOptlimit.put("$limit", 10);
								//从多少条开始查询
								BasicDBObject groupOptskip = new BasicDBObject();
								groupOptskip.put("$skip", 0);
								
						        BasicDBObject orderbyOpt = new BasicDBObject();
						        //设置总分排序 正序1 倒序-1
						        orderbyOpt.append("$sort", new BasicDBObject("totalscore",1));
						          
						        AggregationOutput aggrResult= mongoTemplate.getCollection("shopnetflowday").aggregate( matchMap,group,orderbyOpt,groupOptskip,groupOptlimit);
							 		Iterator<DBObject> iter = aggrResult.results().iterator();
									while (iter.hasNext()) {
										System.out.println(iter.next());
									}
						}

}