MongDB分页java实现

曾经终败给现在 2022-06-05 08:10 260阅读 0赞

# 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<Document> collection = getMongoCollection();
            int number = 30;
            FindIterable<Document> 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<Document> collection = getMongoCollection();
            int numberLinit = 30;
            int numberSkip = 1;
            FindIterable<Document> 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<Document> findIterable) {
            // 获取游标MongoCursor<Document>
            MongoCursor<Document> 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<Document> */
        public static MongoCollection<Document> 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<Document> 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<DBObject> iterator = cur.iterator();
            while (iterator.hasNext()) {
                System.out.println(iterator.next());
            }
    
        }
    
        /** * 获取所有文档，打印 */
        public static void getAllData() {
            MongoCollection<Document> collection = getMongoCollection();
            // 获取迭代器FindIterable<Document>
            FindIterable<Document> 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<Document> findIterable) {
            // 获取游标MongoCursor<Document>
            MongoCursor<Document> 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<Document> 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<Document> collection = getMongoCollection();
            Bson filter = new Document("sheng", "13");
            FindIterable<Document> result = collection.find(filter);
            printDocument(result);
        }
    
        // 查出北京的县
        // db.country.find({'name':{$regex:/县/},'sheng':'11','level':3})
        public static void getXianOfBeiJing() {
            MongoCollection<Document> collection = getMongoCollection();
            Bson filter = new Document("sheng", "11");
            String xian = "县";
            Pattern pattern = Pattern.compile("^.*" + xian.trim() + "$", Pattern.CASE_INSENSITIVE);
            BasicDBObject query = new BasicDBObject();
            query.put("name", pattern);
    
            FindIterable<Document> result = collection.find(filter);
            printDocument(result);
        }
    
        // 获取前30条记录
        public static void getDataLimit() {
            MongoCollection<Document> collection = getMongoCollection();
            int number = 30;
            FindIterable<Document> 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<Document> collection = getMongoCollection();
            int numberLinit = 30;
            int numberSkip = 1;
            FindIterable<Document> 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}}