java driver連接mongodb的三種方法

三種方法中均需要注意，創建client時，會連接認證數據庫，而不是存儲數據的數據庫。

方法一:new MongoClient(new MongoClientURI(url))
注意這種方法中，url中不要跟存儲數據的數據庫名字。

String url = "mongodb://username:password@host:port";
MongoClient mongoClient = new MongoClient(new MongoClientURI(url));

 

方法二：new MongoClient(serverAddress, Arrays.asList(credential))
此方法已經deprecated。

MongoCredential credential = MongoCredential.createCredential(username, 認證數據庫名稱，通常為"admin", password.toCharArray());
ServerAddress serverAddress = new ServerAddress(host, port);
MongoClient mongoClient = new MongoClient(serverAddress, Arrays.asList(credential));

 

方法三：new MongoClient(serverAddress, credential, options)

MongoCredential credential = MongoCredential.createCredential(username, 認證數據庫名稱，通常為"admin", password.toCharArray());
MongoClientOptions options = new MongoClientOptions.Builder().build();
ServerAddress serverAddress = new ServerAddress(host, port);
MongoClient mongoClient = new MongoClient(serverAddress, credential, options);

 

取數據以驗證是否連接成功

import static com.mongodb.client.model.Filters.eq;
MongoDatabase db = mongoClient.getDatabase(db_name);
MongoCollection<Document> collection = db.getCollection("表名");
Document doc = collection.find(eq("列名", 值)).first();
if (doc != null)
    System.out.println(doc.toJson());
mongoClient.close();

pom.xml中mongo driver依賴來自於https://mvnrepository.com/，進去搜mongo java就能找到，copy下來粘貼到我們自己pom.xml文件中。

<dependency>
    <groupId>org.mongodb</groupId>
    <artifactId>mongo-java-driver</artifactId>
    <version>3.12.7</version>
</dependency>