java操作MongoDB

mongodb-driver是mongo官方推出的java連接mongoDB的驅動包，相當於JDBC驅動。 我們通過一個入門的案例來了解mongodb-driver的基本使用

創建工程 mongoDemo, 引入依賴

<dependencies>
 <dependency>
 <groupId>org.mongodb</groupId> 
<artifactId>mongodb‐driver</artifactId>
 <version>3.6.3</version>
 </dependency> 
</dependencies>

創建測試類

import com.mongodb.*;
import com.mongodb.client.*;
import com.mongodb.client.model.Filters;
import org.bson.Document;
import org.bson.conversions.Bson;
import org.junit.Test;
import java.util.ArrayList;
import java.util.List;

public class MogoDBTest {


    private static MongoClient mongoClient;

    static {
        System.out.println("===============MongoDBUtil初始化========================");
        mongoClient = new MongoClient("127.0.0.1", 27017);
        // 大部分用戶使用mongodb都在安全內網下，但如果將mongodb設為安全驗證模式，就需要在客戶端提供用戶名和密碼：
        // boolean auth = db.authenticate(myUserName, myPassword);
        MongoClientOptions.Builder options = new MongoClientOptions.Builder();
        options.cursorFinalizerEnabled(true);
        // options.autoConnectRetry(true);// 自動重連true
        // options.maxAutoConnectRetryTime(10); // the maximum auto connect retry time
        options.connectionsPerHost(300);// 連接池設置為300個連接,默認為100
        options.connectTimeout(30000);// 連接超時，推薦>3000毫秒
        options.maxWaitTime(5000); //
        options.socketTimeout(0);// 套接字超時時間，0無限制
        options.threadsAllowedToBlockForConnectionMultiplier(5000);// 線程隊列數，如果連接線程排滿了隊列就會拋出“Out of semaphores to get db”錯誤。
        options.writeConcern(WriteConcern.SAFE);//
        options.build();
    }

    // =================公用用方法=================
    /**
     * 獲取DB實例 - 指定數據庫，若不存在則創建
     * @param dbName
     * @return
     */
    public static MongoDatabase getDB(String dbName) {
        if (dbName != null && !"".equals(dbName)) {
            MongoDatabase database = mongoClient.getDatabase(dbName);
            return database;
        }
        return null;
    }

    /**
     * 獲取指定數據庫下的collection對象
     * @param collName
     * @return
     */
    public static  MongoCollection<Document> getCollection(String dbName, String collName) {
        if (null == collName || "".equals(collName)) {
            return null;
        }
        if (null == dbName || "".equals(dbName)) {
            return null;
        }
        MongoCollection<Document> collection = mongoClient.getDatabase(dbName).getCollection(collName);
        return collection;
    }

    .....................
}

1.數據庫操作

1.1獲取所有數據庫

  //獲取所有數據庫
    @Test
    public void getAllDBNames(){
        MongoIterable<String> dbNames = mongoClient.listDatabaseNames();
        for (String s : dbNames) {
            System.out.println(s);
        }
    }

1.2.獲取指定庫的所有集合名

    //獲取指定庫的所有集合名
    @Test
    public void getAllCollections(){
        MongoIterable<String> colls = getDB("books").listCollectionNames();
        for (String s : colls) {
            System.out.println(s);
        }
    }

1.3.刪除數據庫

  //刪除數據庫
    @Test
    public void dropDB(){
        //連接到數據庫
        MongoDatabase mongoDatabase =  getDB("test");
        mongoDatabase.drop();
    }

2.文檔操作　　

2.1插入文檔

1.插入單個文檔

    //插入一個文檔
    @Test
    public void insertOneTest(){
        //獲取集合
        MongoCollection<Document> collection = getCollection("books","book");
        //要插入的數據
        Document document = new Document("id",1)
                .append("name", "哈姆雷特")
                .append("price", 67);
        //插入一個文檔
        collection.insertOne(document);
        System.out.println(document.get("_id"));
    }

　2.插入多個文檔

  //插入多個文檔
    @Test
    public void insertManyTest(){
        //獲取集合
        MongoCollection<Document> collection = getCollection("books","book");
        //要插入的數據
        List<Document> list = new ArrayList<>();
        for(int i = 1; i <= 15; i++) {
            Document document = new Document("id",i)
                    .append("name", "book"+i)
                    .append("price", 20+i);
            list.add(document);
        }
        //插入多個文檔
        collection.insertMany(list);
    }

2.2查詢文檔

2.2.1基本查詢

　1.查詢集合所有文檔

    @Test
    public void findAllTest(){
        //獲取集合
        MongoCollection<Document> collection = getCollection("books","book");
        //查詢集合的所有文檔
        FindIterable findIterable= collection.find();
        MongoCursor cursor = findIterable.iterator();
        while (cursor.hasNext()) {
            System.out.println(cursor.next());
        }
    }

2.條件查詢

  @Test
    public void findConditionTest(){
        //獲取集合
        MongoCollection<Document> collection = getCollection("books","book");
        //方法1.構建BasicDBObject  查詢條件 id大於2，小於5
        BasicDBObject queryCondition=new BasicDBObject();
        queryCondition.put("id", new BasicDBObject("$gt", 2));
        queryCondition.put("id", new BasicDBObject("$lt", 5));
        //查詢集合的所有文  通過price升序排序
        FindIterable findIterable= collection.find(queryCondition).sort(new BasicDBObject("price",1));

        //方法2.通過過濾器Filters，Filters提供了一系列查詢條件的靜態方法   id大於2小於5   通過id升序排序查詢
        //Bson filter=Filters.and(Filters.gt("id", 2),Filters.lt("id", 5));
        //FindIterable findIterable= collection.find(filter).sort(Sorts.orderBy(Sorts.ascending("id")));

        //查詢集合的所有文
        MongoCursor cursor = findIterable.iterator();
        while (cursor.hasNext()) {
            System.out.println(cursor.next());
        }
    }

　　

　　

2.2.2 投影查詢

    @Test
    public void findAllTest3(){
        //獲取集合
        MongoCollection<Document> collection = getCollection("books","book");
    　　//查詢id等於1,2,3,4的文檔
        Bson fileter=Filters.in("id",1,2,3,4);
        //查詢集合的所有文檔
        FindIterable findIterable= collection.find(fileter).projection(new BasicDBObject("id",1).append("name",1).append("_id",0));
        MongoCursor cursor = findIterable.iterator();
        while (cursor.hasNext()) {
            System.out.println(cursor.next());
        }
    }

2.3分頁查詢　

2.3.1.統計查詢

//集合的文檔數統計
    @Test
    public void getCountTest() {
        //獲取集合
        MongoCollection<Document> collection = getCollection("books","book");
        //獲取集合的文檔數
        Bson filter = Filters.gt("price", 30);
        int count = (int)collection.count(filter);
        System.out.println("價錢大於30的count==："+count);
    }

　　

2.3.2分頁列表查詢　

    //分頁查詢
    @Test
    public void findByPageTest(){
        //獲取集合
        MongoCollection<Document> collection = getCollection("books","book");
        //分頁查詢  跳過0條，返回前10條
        FindIterable findIterable= collection.find().skip(0).limit(10);
        MongoCursor cursor = findIterable.iterator();
        while (cursor.hasNext()) {
            System.out.println(cursor.next());
        }
        System.out.println("----------取出查詢到的第一個文檔-----------------");
        //取出查詢到的第一個文檔
        Document document = (Document) findIterable.first();
        //打印輸出
        System.out.println(document);
    }

2.4修改文檔

  //修改文檔
    @Test
    public void updateTest(){
        //獲取集合
        MongoCollection<Document> collection = getCollection("books","book");
        //修改id=2的文檔    通過過濾器Filters，Filters提供了一系列查詢條件的靜態方法
        Bson filter = Filters.eq("id", 2);
        //指定修改的更新文檔
        Document document = new Document("$set", new Document("price", 44));
        //修改單個文檔
        collection.updateOne(filter, document);
        //修改多個文檔
      // collection.updateMany(filter, document);
        //修改全部文檔
        //collection.updateMany(new BasicDBObject(),document);
    }

2.5 刪除文檔

  //刪除與篩選器匹配的單個文檔
    @Test
    public void deleteOneTest(){
        //獲取集合
        MongoCollection<Document> collection = getCollection("books","book");
        //申明刪除條件
        Bson filter = Filters.eq("id",3);
        //刪除與篩選器匹配的單個文檔
        collection.deleteOne(filter);

        //刪除與篩選器匹配的所有文檔
       // collection.deleteMany(filter);

        System.out.println("--------刪除所有文檔----------");
        //刪除所有文檔
       // collection.deleteMany(new Document());
    }