MongDB分页java实现

mongodb分页查询

我们知道mongDB分页查询有两个方法，Limit与Skip方法

MongoDB Limit() 方法

如果你需要在MongoDB中读取指定数量的数据记录，可以使用MongoDB的Limit方法

limit()方法接受一个数字参数，该参数指定从MongoDB中读取的记录条数。

语法

脚本中limit()方法基本语法如下所示：

db.country.find().limit(NUMBER)

java代码实现如下：

// 获取前30条记录
    public static void getDataLimit() {
        MongoCollection collection = getMongoCollection();
        int number = 30;
        FindIterable result = collection.find().limit(number);
        printDocument(result);
    }

MongoDB Skip() 方法

我们除了可以使用limit()方法来读取指定数量的数据外，还可以使用skip()方法来跳过指定数量的数据

skip方法同样接受一个数字参数作为跳过的记录条数。

语法

skip() 方法脚本语法格式如下：

db.COLLECTION_NAME.find().limit(NUMBER).skip(NUMBER)
示例：
db.country.find().limit(30).skip(1)

java代码实现：

// 从第二条记录开始，获取30条记录
    public static void getDataLimitSkip() {
        MongoCollection collection = getMongoCollection();
        int numberLinit = 30;
        int numberSkip = 1;
        FindIterable result = collection.find().limit(numberLinit).skip(numberSkip);
        printDocument(result);
    }

printDocument(result)方法实现：

/**
     * 通过游标遍历检索出的文档集合
     * 
     * @param mongoCursor
     */
    public static void printDocument(FindIterable findIterable) {
        // 获取游标MongoCursor
        MongoCursor mongoCursor = findIterable.iterator();
        // 通过游标遍历检索出的文档集合
        while (mongoCursor.hasNext()) {
            System.out.println(mongoCursor.next());
        }
    }

全部完整代码：

package com.adtec.mongodb;

import java.util.Iterator;
import java.util.regex.Pattern;

import org.bson.Document;
import org.bson.conversions.Bson;

import com.mongodb.BasicDBObject;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBCursor;
import com.mongodb.DBObject;
import com.mongodb.MongoClient;
import com.mongodb.client.FindIterable;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoCursor;
import com.mongodb.client.MongoDatabase;

/**
 * 
 * @author 浪丶荡
 *
 */
public class MongoDBUtils {

    public static void main(String[] args) {
        // 获取所有文档，打印
        // getAllData();
        //// 获取记录总数
        // getDataSum();
        // getXianOfHeBei();
        // query(getDB("test"), "country");
        getDataLimit();
        System.out.println("------------------------------------");
        getDataLimitSkip();

    }

    /**
     * 获取集合连接
     * 
     * @return MongoCollection
     */
    public static MongoCollection getMongoCollection() {
        // 连接到 mongodb 服务
        String host = "192.168.71.193";
        int port = 27017;
        @SuppressWarnings("resource")
        MongoClient mongoClient = new MongoClient(host, port);
        // 连接到数据库
        String databaseName = "test";
        MongoDatabase database = mongoClient.getDatabase(databaseName);
        // 选择集合（类似选择表）
        String collectionName = "country";
        MongoCollection collection = database.getCollection(collectionName);
        return collection;

    }

    // 获取DB对象
    public static DB getDB(String dbname) {
        MongoClient mongoClient = new MongoClient("192.168.71.193", 27017);
        DB db = mongoClient.getDB(dbname);
        return db;
    }

    // 模糊查询
    public static void query(DB db, String name) {
        DBCollection dbColl = db.getCollection(name);
        // 完全匹配
        // Pattern pattern = Pattern.compile("^name$",
        // Pattern.CASE_INSENSITIVE);
        // 右匹配
        // Pattern pattern = Pattern.compile("^.*name$",
        // Pattern.CASE_INSENSITIVE);
        // 左匹配
        // Pattern pattern = Pattern.compile("^name.*$",
        // Pattern.CASE_INSENSITIVE);
        // 模糊匹配
        Pattern pattern = Pattern.compile("^.*县.*$", Pattern.CASE_INSENSITIVE);
        // db.country.find({'name':{$regex:/县/},'sheng':'11','level':3})
        BasicDBObject query = new BasicDBObject();
        query.put("name", pattern);
        query.put("sheng", "11");
        query.put("level", 3);
        BasicDBObject sort = new BasicDBObject();
        // 1,表示正序； －1,表示倒序
        sort.put("name", 1);
        DBCursor cur = dbColl.find(query).sort(sort);
        Iterator iterator = cur.iterator();
        while (iterator.hasNext()) {
            System.out.println(iterator.next());
        }

    }

    /**
     * 获取所有文档，打印
     */
    public static void getAllData() {
        MongoCollection collection = getMongoCollection();
        // 获取迭代器FindIterable
        FindIterable findIterable = collection.find();

        printDocument(findIterable);

    }

    /**
     * 通过游标遍历检索出的文档集合
     * 
     * @param mongoCursor
     */
    public static void printDocument(FindIterable findIterable) {
        // 获取游标MongoCursor
        MongoCursor mongoCursor = findIterable.iterator();
        // 通过游标遍历检索出的文档集合
        while (mongoCursor.hasNext()) {
            System.out.println(mongoCursor.next());
        }
    }

    // 获取记录总数
    public static void getDataSum() {
        MongoCollection collection = getMongoCollection();
        long sum = collection.count();
        System.out.println(sum);
    }

    // 查出河北省的县
    // db.country.find({'sheng':'13'})
    public static void getXianOfHeBei() {
        MongoCollection collection = getMongoCollection();
        Bson filter = new Document("sheng", "13");
        FindIterable result = collection.find(filter);
        printDocument(result);
    }

    // 查出北京的县
    // db.country.find({'name':{$regex:/县/},'sheng':'11','level':3})
    public static void getXianOfBeiJing() {
        MongoCollection collection = getMongoCollection();
        Bson filter = new Document("sheng", "11");
        String xian = "县";
        Pattern pattern = Pattern.compile("^.*" + xian.trim() + "$", Pattern.CASE_INSENSITIVE);
        BasicDBObject query = new BasicDBObject();
        query.put("name", pattern);

        FindIterable result = collection.find(filter);
        printDocument(result);
    }

    // 获取前30条记录
    public static void getDataLimit() {
        MongoCollection collection = getMongoCollection();
        int number = 30;
        FindIterable result = collection.find().limit(number);
        printDocument(result);
    }

    // 从第二条记录开始，获取30条记录
    public static void getDataLimitSkip() {
        MongoCollection collection = getMongoCollection();
        int numberLinit = 30;
        int numberSkip = 1;
        FindIterable result = collection.find().limit(numberLinit).skip(numberSkip);
        printDocument(result);
    }
}

结果：

十一月 22, 2017 10:39:45 上午 com.mongodb.diagnostics.logging.JULLogger log
信息: Cluster created with settings {hosts=[192.168.71.193:27017], mode=SINGLE, requiredClusterType=UNKNOWN, serverSelectionTimeout='30000 ms', maxWaitQueueSize=500}
十一月 22, 2017 10:39:45 上午 com.mongodb.diagnostics.logging.JULLogger log
信息: Opened connection [connectionId{localValue:1, serverValue:18}] to 192.168.71.193:27017
十一月 22, 2017 10:39:45 上午 com.mongodb.diagnostics.logging.JULLogger log
信息: Monitor thread successfully connected to server with description ServerDescription{address=192.168.71.193:27017, type=STANDALONE, state=CONNECTED, ok=true, version=ServerVersion{versionList=[3, 4, 5]}, minWireVersion=0, maxWireVersion=5, maxDocumentSize=16777216, roundTripTimeNanos=1532285}
十一月 22, 2017 10:39:45 上午 com.mongodb.diagnostics.logging.JULLogger log
信息: No server chosen by ReadPreferenceServerSelector{readPreference=primary} from cluster description ClusterDescription{type=UNKNOWN, connectionMode=SINGLE, serverDescriptions=[ServerDescription{address=192.168.71.193:27017, type=UNKNOWN, state=CONNECTING}]}. Waiting for 30000 ms before timing out
十一月 22, 2017 10:39:45 上午 com.mongodb.diagnostics.logging.JULLogger log
信息: Opened connection [connectionId{localValue:2, serverValue:19}] to 192.168.71.193:27017
Document{{_id=59ec5362e0781ef646f5ad03, country=China}}
Document{{_id=59ec55aa937ceb812c804c53, code=110000, sheng=11, di=00, xian=00, name=北京市, level=1.0}}
Document{{_id=59ec563f937ceb812c804c54, code=110000, sheng=11, di=00, xian=00, name=北京市, level=1.0}}
Document{{_id=59ec563f937ceb812c804c55, code=110100, sheng=11, di=01, xian=00, name=市辖区, level=2.0}}
Document{{_id=59ec563f937ceb812c804c56, code=110101, sheng=11, di=01, xian=01, name=东城区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c57, code=110102, sheng=11, di=01, xian=02, name=西城区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c58, code=110105, sheng=11, di=01, xian=05, name=朝阳区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c59, code=110106, sheng=11, di=01, xian=06, name=丰台区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c5a, code=110107, sheng=11, di=01, xian=07, name=石景山区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c5b, code=110108, sheng=11, di=01, xian=08, name=海淀区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c5c, code=110109, sheng=11, di=01, xian=09, name=门头沟区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c5d, code=110111, sheng=11, di=01, xian=11, name=房山区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c5e, code=110112, sheng=11, di=01, xian=12, name=通州区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c5f, code=110113, sheng=11, di=01, xian=13, name=顺义区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c60, code=110114, sheng=11, di=01, xian=14, name=昌平区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c61, code=110115, sheng=11, di=01, xian=15, name=大兴区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c62, code=110116, sheng=11, di=01, xian=16, name=怀柔区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c63, code=110117, sheng=11, di=01, xian=17, name=平谷区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c64, code=110200, sheng=11, di=02, xian=00, name=县, level=2.0}}
Document{{_id=59ec563f937ceb812c804c65, code=110228, sheng=11, di=02, xian=28, name=密云县, level=3.0}}
Document{{_id=59ec563f937ceb812c804c66, code=110229, sheng=11, di=02, xian=29, name=延庆县, level=3.0}}
Document{{_id=59ec563f937ceb812c804c67, code=120000, sheng=12, di=00, xian=00, name=天津市, level=1.0}}
Document{{_id=59ec563f937ceb812c804c68, code=120100, sheng=12, di=01, xian=00, name=市辖区, level=2.0}}
Document{{_id=59ec563f937ceb812c804c69, code=120101, sheng=12, di=01, xian=01, name=和平区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c6a, code=120102, sheng=12, di=01, xian=02, name=河东区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c6b, code=120103, sheng=12, di=01, xian=03, name=河西区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c6c, code=120104, sheng=12, di=01, xian=04, name=南开区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c6d, code=120105, sheng=12, di=01, xian=05, name=河北区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c6e, code=120106, sheng=12, di=01, xian=06, name=红桥区, level=3.0}}
Document{{_id=59ec571a937ceb812c804c6f, code=120110, sheng=12, di=01, xian=10, name=东丽区, level=3.0}}
------------------------------------
十一月 22, 2017 10:39:45 上午 com.mongodb.diagnostics.logging.JULLogger log
信息: Cluster created with settings {hosts=[192.168.71.193:27017], mode=SINGLE, requiredClusterType=UNKNOWN, serverSelectionTimeout='30000 ms', maxWaitQueueSize=500}
十一月 22, 2017 10:39:45 上午 com.mongodb.diagnostics.logging.JULLogger log
信息: No server chosen by ReadPreferenceServerSelector{readPreference=primary} from cluster description ClusterDescription{type=UNKNOWN, connectionMode=SINGLE, serverDescriptions=[ServerDescription{address=192.168.71.193:27017, type=UNKNOWN, state=CONNECTING}]}. Waiting for 30000 ms before timing out
十一月 22, 2017 10:39:45 上午 com.mongodb.diagnostics.logging.JULLogger log
信息: Opened connection [connectionId{localValue:3, serverValue:20}] to 192.168.71.193:27017
十一月 22, 2017 10:39:45 上午 com.mongodb.diagnostics.logging.JULLogger log
信息: Monitor thread successfully connected to server with description ServerDescription{address=192.168.71.193:27017, type=STANDALONE, state=CONNECTED, ok=true, version=ServerVersion{versionList=[3, 4, 5]}, minWireVersion=0, maxWireVersion=5, maxDocumentSize=16777216, roundTripTimeNanos=1007126}
十一月 22, 2017 10:39:45 上午 com.mongodb.diagnostics.logging.JULLogger log
信息: Opened connection [connectionId{localValue:4, serverValue:21}] to 192.168.71.193:27017
Document{{_id=59ec55aa937ceb812c804c53, code=110000, sheng=11, di=00, xian=00, name=北京市, level=1.0}}
Document{{_id=59ec563f937ceb812c804c54, code=110000, sheng=11, di=00, xian=00, name=北京市, level=1.0}}
Document{{_id=59ec563f937ceb812c804c55, code=110100, sheng=11, di=01, xian=00, name=市辖区, level=2.0}}
Document{{_id=59ec563f937ceb812c804c56, code=110101, sheng=11, di=01, xian=01, name=东城区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c57, code=110102, sheng=11, di=01, xian=02, name=西城区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c58, code=110105, sheng=11, di=01, xian=05, name=朝阳区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c59, code=110106, sheng=11, di=01, xian=06, name=丰台区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c5a, code=110107, sheng=11, di=01, xian=07, name=石景山区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c5b, code=110108, sheng=11, di=01, xian=08, name=海淀区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c5c, code=110109, sheng=11, di=01, xian=09, name=门头沟区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c5d, code=110111, sheng=11, di=01, xian=11, name=房山区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c5e, code=110112, sheng=11, di=01, xian=12, name=通州区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c5f, code=110113, sheng=11, di=01, xian=13, name=顺义区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c60, code=110114, sheng=11, di=01, xian=14, name=昌平区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c61, code=110115, sheng=11, di=01, xian=15, name=大兴区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c62, code=110116, sheng=11, di=01, xian=16, name=怀柔区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c63, code=110117, sheng=11, di=01, xian=17, name=平谷区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c64, code=110200, sheng=11, di=02, xian=00, name=县, level=2.0}}
Document{{_id=59ec563f937ceb812c804c65, code=110228, sheng=11, di=02, xian=28, name=密云县, level=3.0}}
Document{{_id=59ec563f937ceb812c804c66, code=110229, sheng=11, di=02, xian=29, name=延庆县, level=3.0}}
Document{{_id=59ec563f937ceb812c804c67, code=120000, sheng=12, di=00, xian=00, name=天津市, level=1.0}}
Document{{_id=59ec563f937ceb812c804c68, code=120100, sheng=12, di=01, xian=00, name=市辖区, level=2.0}}
Document{{_id=59ec563f937ceb812c804c69, code=120101, sheng=12, di=01, xian=01, name=和平区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c6a, code=120102, sheng=12, di=01, xian=02, name=河东区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c6b, code=120103, sheng=12, di=01, xian=03, name=河西区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c6c, code=120104, sheng=12, di=01, xian=04, name=南开区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c6d, code=120105, sheng=12, di=01, xian=05, name=河北区, level=3.0}}
Document{{_id=59ec563f937ceb812c804c6e, code=120106, sheng=12, di=01, xian=06, name=红桥区, level=3.0}}
Document{{_id=59ec571a937ceb812c804c6f, code=120110, sheng=12, di=01, xian=10, name=东丽区, level=3.0}}
Document{{_id=59ec571a937ceb812c804c70, code=120111, sheng=12, di=01, xian=11, name=西青区, level=3.0}}