Java Manipulation Mongodb_3 (a preliminary study of MongoDB)

By opening the MongoDB jar package you can see that the MONGO class has many methods, including getaddress (), Dropdatabase (String), Getdb (string), and so on. Here are one by one demonstrations of the use of Mongo.class.

The demo of MONGO is done primarily in a test class, so I've built a junittest_1 Java class here. The main code is as follows, because the comments are rich, not explained.

Import Com.mongodb.Mongo;

public class Junittest_1 {

@Test

public void Test1 () throws exception{

Mongo Mongo = new Mongo ();

Get all the databases

List<string> dbs = Mongo.getdatabasenames ();

for (String Db:dbs) {

SYSTEM.OUT.PRINTLN (DB);

}

Get the current MongoDB version

System.out.println ("MONGO Version =" + Mongo.getversion ());

Get server address

SYSTEM.OUT.PRINTLN ("MONGO server address =" + mongo.getaddress ());

Delete a database

Mongo.dropdatabase ("test");

You can also view the maximum setting value for a Bson document

System.out.println ("bsonobjectsize =" + mongo.getmaxbsonobjectsize ());

Debugstring

System.out.println ("debugstring =" + mongo.debugstring ());

Mongo.close ();

}

}

Running on my computer, the results of the output are as follows:

Local

Test

MONGO Version = 2.10.1

MONGO server address =/127.0.0.1:27017

Bsonobjectsize = 16777216

debugstring = Dbtcpconnector:/127.0.0.1:27017/127.0.0.1:27017

In practice, it is recommended to use mongoclient instead of the MONGO class. The calling test code for the Mongoclient class is as follows

public void Test2 () throws exception{

Mongoclient client = new Mongoclient ();

Querying all the current databases

List<string> dbs = Client.getdatabasenames ();

for (String Db:dbs) {

SYSTEM.OUT.PRINTLN (DB);

}

Get the current MongoDB version

System.out.println ("MONGO Version =" + Client.getversion ());

Get server address

SYSTEM.OUT.PRINTLN ("MONGO server address =" + client.getaddress ());

Delete a database

Client.dropdatabase ("test");

You can also view the maximum setting value for a Bson document

System.out.println ("bsonobjectsize =" + client.getmaxbsonobjectsize ());

Debugstring

System.out.println ("debugstring =" + client.debugstring ());

Client.close ();

}

The print results are as shown.

Java Manipulation Mongodb_3 (a preliminary study of MongoDB)