MongoDB java List数据库名称和与其相关的集合

import com.mongodb.MongoClient;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import org.bson.Document;

public class MongoDBExample {
    public static void main(String[] args) {
        // 连接MongoDB数据库
        MongoClient mongoClient = new MongoClient("localhost", 27017);
        // 获取数据库
        MongoDatabase database = mongoClient.getDatabase("mydb");
        // 获取集合
        MongoCollection<Document> collection = database.getCollection("mycollection");

        // 插入文档
        Document document = new Document("name", "John")
                .append("age", 30)
                .append("city", "New York");
        collection.insertOne(document);

        // 查询文档
        Document query = new Document("name", "John");
        Document result = collection.find(query).first();
        System.out.println(result);

        // 更新文档
        Document updateQuery = new Document("name", "John");
        Document update = new Document("$set", new Document("age", 31));
        collection.updateOne(updateQuery, update);

        // 删除文档
        Document deleteQuery = new Document("name", "John");
        collection.deleteOne(deleteQuery);

        // 关闭连接
        mongoClient.close();
    }
}