mongoDB数据库连接

/*
mongoDB连接模块
建议mongod.cfg配置文件增加directoryPerDB: true，表示每个数据库均保存在独立同名文件夹中

# Where and how to store data.
storage:
  dbPath: D:\Program Files\MongoDB\Server\6.0\data\db
  directoryPerDB: true
  journal:
    enabled: true


不认证直接链接数据库
public MongoClient getConn()
通过用户密码认证链接数据库
public MongoClient getConnByCredit()
使用示例：
        mongoConnection = new MongoDbConnection();
        //新建连接
        mongoClient = mongoConnection.getConn();
        //连接数据库对象，如果不存在，创建
        database = mongoClient.getDatabase(databaseName);
        //处理数据...
        mongoGridFS.readFromGridFS("D:\\temp","GAAA0127.mp4");
        //关闭连接
        mongoClient.close();

ChenLX，2023.5.15
 */
package mongo.gdsky.com.cn;

import com.mongodb.*;
import com.mongodb.MongoClient;
import com.mongodb.client.*;

import java.util.ArrayList;
import java.util.List;

//mongoDB数据库连接
public class MongoDbConnection {
    //不认证直接链接数据库
    public MongoClient getConn(){
        MongoClient mongoClient = new MongoClient("localhost",27017);
        //也可使用MongoClientURI
        // MongoClientURI mongoClientURI = new MongoClientURI("mongodb://localhost:27017");
        // MongoClient mongoClient = new MongoClient(mongoClientURI);
        return mongoClient;

    }

//通过用户密码认证链接数据库

    public MongoClient getConnByCredit(){
        String name = "test";//用户名
        String dbName = "myDB";//数据库名
        char [] pwd = "test".toCharArray();//用户密码(将字符串转换成字符数组)
        List<ServerAddress> addresses = new ArrayList<>();
        //服务器地址：链接地址,端口号
        ServerAddress address = new ServerAddress("localhost",27017);
        addresses.add(address);
        List<MongoCredential> credentials = new ArrayList<>();
        //认证方法需要三个参数，用户名，数据库名，用户密码
        MongoCredential credential = MongoCredential.createScramSha1Credential(name,dbName,pwd);
        credentials.add(credential);
        //创建链接对象
        MongoClient mongoClient = new MongoClient(addresses,credentials);
        return mongoClient;
    }


    //测试是否连接成功

    public static void main(String[] args) {

        MongoDbConnection mongoDbConnection = new MongoDbConnection();
        MongoDatabase mongoDatabase = null;
        MongoClient mongoClient = mongoDbConnection.getConn();
        //MongoClient mongoClient = mongoDBConnection.getConnByCredit();
        // 查询所有数据库名称
        MongoIterable<String> dbNameList = mongoClient.listDatabaseNames();
        System.out.println("查询所有数据库名称:");
        for(String dbName : dbNameList)
            System.out.println(dbName);
        //创建数据库对象
        mongoDatabase = mongoClient.getDatabase("myDB");
        //查询Test数据库中所有集合名称
        MongoIterable<String> colNameList = mongoDatabase.listCollectionNames();
        System.out.println("查询myDB数据库中所有集合名称:");
        for(String colName: colNameList)
            System.out.println(colName);
        //关闭连接
        mongoClient.close();

    }

}