一，问题描述

数据格式： id, timeStamp,count

条件1：查询 某个时间段 内的数据： timeStamp BETWEEN startTime AND endTime。比如 timeStamp BETWEEN 1499875200  AND 1499875600

条件2：记录 的 id 字段 属于某集合： id IN (1001,1002,1003)

条件3：记录 的count字段 大于某个阈值，比如： count > 10000

二，代码实现

条件1实现如下， $gte (greater equal)表示“大于等于 ”。【$lte(lower equal)】表示“小于等于”

private DBObject timeCondi(long startTimeStamp, longendTimeStamp){

DBObject queryCondition= new BasicDBObject("$gte", startTimeStamp).append("$lte", endTimeStamp);

BasicDBObject query= new BasicDBObject("timeStamp", queryCondition);returnquery;

}

条件2的实现如下，使用 $in ArrayList 来表示 id IN (1001,1002,1003)

privateDBObject inCondi() {

List idList = new ArrayList();

idList.add(1001);

idList.add(1002);

idList.add(1003);

BasicDBObject inQuery= newBasicDBObject();

inQuery.put("id", new BasicDBObject("$in", idList));returninQuery;

}

组合条件1 和 条件2 查询：(条件1 AND 条件2).List 将所有 AND 组合的条件add进去，然后使用 $and 组合。

private DBObject andQuery(long startTimeStamp, longendTimeStamp) {

DBObject timeCondi=timeCondi(startTimeStamp, endTimeStamp);

DBObject inCondi=inCondi();

List andCondi = new ArrayList();

andCondi.add(timeCondi);//组合 条件1

andCondi.add(inCondi);//组合 条件2

BasicDBObject andQuery= newBasicDBObject();

andQuery.put("$and", andCondi);returnandQuery;

}

条件3：记录 的count字段 大于某个阈值，比如： count > 10000

private DBObject countCondi(intsize) {

DBObject queryCondition= new BasicDBObject("$gte", size);

BasicDBObject query= new BasicDBObject("count", queryCondition);returnquery;

}

WINDOWS下安装好MongoDB后，MongoDB采用Clietn--Server 模式。WIN10下启动MongoDB服务端：-dbpath 指定 数据存储目录(可自己指定一个)

D:\Program Files\MongoDB\Server\3.4\bin>.\mongod.exe -dbpath ..\data

另起一个 Cmd命令行，输入：

D:\Program Files\MongoDB\Server\3.4\bin>.\mongo.exe

就可以以Shell方式操作MongoDB了。

输入 exit 退出

D:\Program Files\MongoDB\Server\3.4\bin>netstat -ano | findstr 27017  查看端口是否开启。

另外，推荐一个MongoDB的可视化工具：RoboMongoDB。执行相应的查询语句如下：

三，新版本MongoDB(3.0版本以上)，使用Filters来组合多个条件

查询 timeStamp 在[startTimeStamp, endTimeStamp) 内的所有document

1 private static Bson timeBetweenCondition(long startTimeStamp, longendTimeStamp) {2 Bson condition = Filters.and(Filters.gte("timeStamp", startTimeStamp), Filters.lt("timeStamp", endTimeStamp));3 returncondition;4 }

上面的示例，使用Filters的and方法连接了两个条件，其实还可以连接多个条件：比如查询 timeStamp 在[startTimeStamp, endTimeStamp) 区间内，并且 uid 在Listuids 内的document

1 private static Bson multipleAndCondition(long startTimeStamp, long endTimeStamp, Listuids) {2 Bson condition = Filters.and(Filters.gte("timeStamp", startTimeStamp), Filters.lt("timeStamp", endTimeStamp), Filters.in("uid", uids));3 returncondition;4 }

Filters还组合了 IN 条件：比如，查询 uid 在[123, 456, 789]中，可用如下条件：

1 private static Bson uidInCondition(Listuids) {2 Bson condition = Filters.in("uid", uids);3 returncondition;4 }

具体更多的条件查询，可查看Filters的源代码。关于Filters的更多的用法可参考：Filters的若干使用示例

四，MongoDB查询时，过滤某些字段

使用Document对象来指定需要查询或者排除的字段。0 表示不返回该字段的值，1 表示返回该字段的值。

1 //0 表示 不返回 该字段, 1 表示 返回该字段

2 private staticDocument fetchFields() {3 Document fetchFields = newDocument();4 fetchFields.put("_id", 0);//查询的结果 不返回 _id 字段

5 fetchFields.put("uid", 1);//返回 uid 字段

6 fetchFields.put("chat", 1);//返回 chat 字段

7 returnfetchFields;8 }

然后再将 fetchFields 对象传入 project()方法即可，如下：

collection.find(timeBetweenCondition(startTimeStamp, endTimeStamp)).projection(fetchFields())

整个完整示例参考：

importcom.mongodb.MongoClient;importcom.mongodb.client.MongoCollection;importcom.mongodb.client.MongoCursor;importcom.mongodb.client.MongoDatabase;importcom.mongodb.client.model.Filters;importorg.bson.Document;importorg.bson.conversions.Bson;importjava.time.LocalDateTime;importjava.time.ZoneId;importjava.util.Arrays;importjava.util.List;//import static com.mongodb.client.model.Filters.*;

/*** Created by Administrator on 2017/10/20.*/

public classMongoUtil {private static final String HOST = "localhost";private static final int PORT = 27017;private static final String DB_NAME = "test";private static final MongoClient mongoClient = newMongoClient(HOST, PORT);private staticMongoDatabase getDataBase() {returnmongoClient.getDatabase(DB_NAME);

}private static MongoCollectiongetCollection(String collName) {returngetDataBase().getCollection(collName);

}private static Bson timeBetweenCondition(long startTimeStamp, longendTimeStamp) {

Bson condition= Filters.and(Filters.gte("timeStamp", startTimeStamp), Filters.lt("timeStamp", endTimeStamp));returncondition;

}private static Bson uidInCondition(Listuids) {

Bson condition= Filters.in("uid", uids);returncondition;

}private static Bson multipleAndCondition(long startTimeStamp, long endTimeStamp, Listuids) {

Bson condition= Filters.and(Filters.gte("timeStamp", startTimeStamp), Filters.lt("timeStamp", endTimeStamp), Filters.in("uid", uids));returncondition;

}//0 表示 不抽取该字段, 1 表示 抽取该字段

private staticDocument fetchFields() {

Document fetchFields= newDocument();

fetchFields.put("_id", 0);//查询的结果 不返回 _id 字段

fetchFields.put("uid", 1);//返回 uid 字段

fetchFields.put("chat", 1);//返回 chat 字段

returnfetchFields;

}public static voidmain(String[] args) {

MongoCollection collection= getCollection("mycollection_name");

LocalDateTime today= LocalDateTime.of(2017, 8, 29, 0, 0, 0);

LocalDateTime tomorrow= today.plusDays(1);long startTimeStamp =today.atZone(ZoneId.systemDefault()).toEpochSecond();long endTimeStamp =tomorrow.atZone(ZoneId.systemDefault()).toEpochSecond();

Bson andCondition= multipleAndCondition(startTimeStamp, endTimeStamp, Arrays.asList(65496L));//Bson andCondition = timeBetweenCondition(startTimeStamp, endTimeStamp);

Document fetchFields =fetchFields();

MongoCursor cursor = collection.find(andCondition).projection(fetchFields).iterator();long count =collection.count(andCondition);

System.out.println(count);while(cursor.hasNext()) {

Document document=cursor.next();

String chat= (String) document.get("chat");

Long uid= (Long) document.get("uid");

System.out.println("chat:" + chat + ", uid:" +uid);

}

}

}

五：参考文献

https://www.mkyong.com/mongodb/java-mongodb-query-document/

http://farenda.com/mongodb/mongodb-filtering-sorting-and-projections/

原文：http://www.cnblogs.com/hapjin/p/7450309.html