Java - 如何从 MongoDatabase 类获取 DB 对象，因为 MongoClient.getDB(dbName) 已弃用

Question

Here is the old code:

String uri = "mongodb://" + dbUser + ":" + dbPass + "@" + servers + "/"+dbName+ "?ssl=true&authSource=admin&connectTimeoutMS=6000&socketTimeoutMS=6000";  
MongoClientURI uriObj = new MongoClientURI(uri);            
MongoClient client = new MongoClient(uriObj);

DB db = client.getDB(dbName);  ==> deprecated  

Since MongoClient.getDB(dbName) is deprecated, here is the new code:

String uri = "mongodb://" + dbUser + ":" + dbPass + "@" + servers + "/"+dbName+ "?ssl=true&authSource=admin&connectTimeoutMS=6000&socketTimeoutMS=6000";  
MongoClientURI uriObj = new MongoClientURI(uri);            
MongoClient client = new MongoClient(uriObj);

MongoDatabase database = client.getDatabase(dbName);  ==> How to get DB db?

How to get a DB object (as DB db in the old code) from the new code?

Answer 1

Exactly your code DB db = mongoClient.getDB(dbName); is for mongodb java drivers versions like 2.14.2 and 2.13.3 . Below is for newer, since 3.0.4 and 3.7.1 .

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As mentioned in the documentation:

Use MongoClients.create(), or MongoClient() for the legacy MongoClient API, to make a connection to a running MongoDB instance.

up to version 3.7 (Legacy MongoClient API), you can use connection string and getDatabase() method to access a database like:

MongoClient mongoClient = new MongoClient(new MongoClientURI("mongodb://user1:pwd1@host1/?authSource=db1&ssl=true"));
MongoDatabase database = mongoClient.getDatabase("db_name");

or by the same logic:

MongoClientURI uri = new MongoClientURI("mongodb://user1:pwd1@host1/?authSource=db1&ssl=true");
MongoClient mongoClient = new MongoClient(uri);
MongoDatabase database = mongoClient.getDatabase("db_name");

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New MongoClient API ( since 3.7 )

To make a connection to a running MongoDB instance and to access a database , you can use:

MongoClient mongoClient = MongoClients.create("mongodb://user1:pwd1@host1/?authSource=db1&ssl=true");
MongoDatabase database = mongoClient.getDatabase("db_name");

Specify the name of the database to the getDatabase() method. If a database does not exist, MongoDB creates the database when you first store data for that database.