import com.mongodb.MongoClient;
import com.mongodb.MongoCredential;
import com.mongodb.ServerAddress;
import com.mongodb.client.MongoDatabase;

String user; // the user name
String database; // the name of the database in which the user is defined
char[] password; // the password as a character array
// ...

MongoCredential credential = MongoCredential.createCredential(user, database, password);

MongoClientSettings settings = MongoClientSettings.builder()
        .credential(credential)
        .applyToSslSettings(builder -> builder.enabled(true))
        .applyToClusterSettings(builder ->
            builder.hosts(Arrays.asList(new ServerAddress("host1", 27017))))
        .build();

MongoClient mongoClient = MongoClients.create(settings);

package top.sanshishu;

import java.util.Arrays;

import org.bson.Document;

import com.mongodb.*;
import com.mongodb.client.FindIterable;
import com.mongodb.client.MongoClient;
import com.mongodb.client.MongoClients;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoCursor;
import com.mongodb.client.MongoDatabase;

public class MainToDo {

	public static void main(String[] args) {
		// TODO 自动生成的方法存根
		try {

			String strMDBUser; // the user name
			String strMDBDB; // the name of the database in which the user is defined
			char[] achMDBPW; // the password as a character array
			// ...

			strMDBUser = "Berry";
			strMDBDB = "dbBBS";
			achMDBPW = "Berry".toCharArray();

			MongoCredential credential = MongoCredential.createCredential(strMDBUser, strMDBDB, achMDBPW);

			MongoClientSettings settings = MongoClientSettings.builder().credential(credential)
					.applyToClusterSettings(
							builder -> builder.hosts(Arrays.asList(new ServerAddress("127.0.0.1", 27017))))
					.build();


			MongoClient mongoClient = MongoClients.create(settings);

			// 连接到数据库
			MongoDatabase mongoDatabase = mongoClient.getDatabase("dbBBS");
			System.out.println("Connect to database dbBBS successfully");

			// 列出所有Collection的名字
			for (String name : mongoDatabase.listCollectionNames()) {
			    System.out.println(name);
			};


			MongoCollection<Document> collection = mongoDatabase.getCollection("tbMessage");
			System.out.println("集合 tbMessage 选择成功");

			// 检索所有文档
			/**
			 * 1. 获取迭代器FindIterable<Document> 2. 获取游标MongoCursor<Document> 3. 通过游标遍历检索出的文档集合
			 */
			FindIterable<Document> findIterable = collection.find();
			MongoCursor<Document> cursor = findIterable.iterator();
			try {
				while (cursor.hasNext()) {
					System.out.println(cursor.next().toJson());
				}
			} finally {
				cursor.close();
			}

			//就显示第一条文档
//			Document myDoc = collection.find().first();
//			System.out.println(myDoc.toJson());

		} catch (Exception e) {
			System.err.println(e.getClass().getName() + ": " + e.getMessage());
		}
	}
}