Connecting to a Database

• Connecting to a replica set

  mongodb://<username>:<password>@<instance_ip>:<instance_port>/<database_name>?authSource=admin&replicaSet=replica&ssl=true

  Table 1 Parameters

  Parameter	Description
  <username>	Current username.
  <password>	Password for the current username.
  <instance_ip>	If you access an instance from an ECS, instance_ip is the private IP address of the instance.
  	If you access an instance through an EIP, instance_ip is the EIP that has been bound to the instance.
  <instance_port>	Database port displayed on the Basic Information page. Default value: 8635
  <database_name>	Name of the database to be connected.
  authSource	Authentication user database. The value is admin.
  ssl	Connection mode. true indicates that SSL will be used.

Example script in Java:

import java.util.ArrayList;
import java.util.List;
import org.bson.Document;
import com.mongodb.MongoClient;
import com.mongodb.MongoCredential;
import com.mongodb.ServerAddress;
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.MongoCollection;
import com.mongodb.MongoClientURI;
import com.mongodb.MongoClientOptions;
public class MongoDBJDBC {
public static void main(String[] args){
      try {
              System.setProperty("javax.net.ssl.trustStore", "/home/Mike/jdk1.8.0_112/jre/lib/security/mongostore");
              System.setProperty("javax.net.ssl.trustStorePassword", "****");
              ServerAddress serverAddress = new ServerAddress("ip", port);
              List addrs = new ArrayList();
              addrs.add(serverAddress);
              // There will be security risks if the username and password used for authentication are directly written into code. Store the username and password in ciphertext in the configuration file or environment variables.
              // In this example, the username and password are stored in the environment variables. Before running this example, set environment variables EXAMPLE_USERNAME_ENV and EXAMPLE_PASSWORD_ENV as needed.
              String userName = System.getenv("EXAMPLE_USERNAME_ENV");
              String rwuserPassword = System.getenv("EXAMPLE_PASSWORD_ENV");
              MongoCredential credential = MongoCredential.createScramSha1Credential("rwuser", "admin", rwuserPassword.toCharArray());
              List credentials = new ArrayList();
              credentials.add(credential);
              MongoClientOptions opts= MongoClientOptions.builder()
              .sslEnabled(true)
              .sslInvalidHostNameAllowed(true)
              .build();
              MongoClient mongoClient = new MongoClient(addrs,credentials,opts);
              MongoDatabase mongoDatabase = mongoClient.getDatabase("testdb");
              MongoCollection collection = mongoDatabase.getCollection("testCollection");
              Document document = new Document("title", "MongoDB").
              append("description", "database").
              append("likes", 100).
              append("by", "Fly");
              List documents = new ArrayList();
              documents.add(document);
              collection.insertMany(documents);
              System.out.println("Connect to database successfully");
              } catch (Exception e) {
              System.err.println( e.getClass().getName() + ": " + e.getMessage() );
         }
      }
}

Sample code:

javac -cp .:mongo-java-driver-3.2.0.jar MongoDBJDBC.java

java -cp .:mongo-java-driver-3.2.0.jar MongoDBJDBC

• Connecting to a replica set

  mongodb://<username>:<password>@<instance_ip>:<instance_port>/<database_name>?authSource=admin&replicaSet=replica

  Table 2 Parameters

  Parameter	Description
  <username>	Current username.
  <password>	Password for the current username.
  <instance_ip>	If you access an instance from an ECS, instance_ip is the private IP address of the instance.
  	If you access an instance through an EIP, instance_ip is the EIP that has been bound to the instance.
  <instance_port>	Database port displayed on the Basic Information page. Default value: 8635
  <database_name>	Name of the database to be connected.
  authSource	Authentication user database. The value is admin.

Example script in Java:

import com.mongodb.ConnectionString;
import com.mongodb.reactivestreams.client.MongoClients;
import com.mongodb.reactivestreams.client.MongoClient;
import com.mongodb.reactivestreams.client.MongoDatabase;
import com.mongodb.MongoClientSettings;
public class MyConnTest { 
    final public static void main(String[] args) { 
	try {
        // no ssl 
	ConnectionString connString = new ConnectionString("mongodb://rwuser:****@192.*.*.*:8635,192.*.*.*:8635/test? authSource=admin");
	MongoClientSettings settings = MongoClientSettings.builder()
		.applyConnectionString(connString)
		.retryWrites(true)
		.build();
	MongoClient mongoClient = MongoClients.create(settings);
	MongoDatabase database = mongoClient.getDatabase("test");
     System.out.println("Connect to database successfully");  
	} catch (Exception e) { 
            e.printStackTrace(); 
            System.out.println("Test failed"); 
        } 
}
} 

• Connecting to a replica set

  spring:
    data:
      mongodb:
        uri: mongodb://<username>:<password>@<instance_ip>:<instance_port>/<database_name>?authSource=admin&replicaSet=replica

  Table 3 Parameters

  Parameter	Description
  <username>	Current username.
  <password>	Password for the current username.
  <instance_ip>	If you access an instance from an ECS, instance_ip is the private IP address of the instance.
  	If you access an instance through an EIP, instance_ip is the EIP that has been bound to the instance.
  <instance_port>	Database port displayed on the Basic Information page. Default value: 8635
  <database_name>	Name of the database to be connected.
  authSource	Authentication user database. The value is admin.

  Example script using YML file:

  • application.yml

    spring:
      data:
        mongodb:
          uri: mongodb://<username>:<password>@<instance_ip>:<instance_port>/<database_name>?authSource=admin&replicaSet=replica

  • ITestService.java

    package com.springboot.cli.service;
    public interface ITestService {
        long doCount();
    }

  • TestServiceImpl.java

    package com.springboot.cli.service.impl;
    import com.springboot.cli.service.ITestService;
    import lombok.RequiredArgsConstructor;
    import org.springframework.data.mongodb.core.MongoTemplate;
    import org.springframework.stereotype.Service;
    @Service
    @RequiredArgsConstructor
    public class TestServiceImpl implements ITestService {
        private final MongoTemplate mongoTemplate;
        @Override
        public long doCount() {
            return mongoTemplate.estimatedCount("coll");
        }
    }

  • MongodbApplicationTests.java

    package com.springboot.cli;
    import com.springboot.cli.service.impl.TestServiceImpl;
    import org.junit.jupiter.api.Test;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.boot.test.context.SpringBootTest;
    import org.springframework.stereotype.Service;
    @SpringBootTest
    @Service
    class MongodbApplicationTests {
        @Autowired
        TestServiceImpl testService;
        @Test
        void doCount() {
            System.out.println("coll count is: " + testService.doCount());
        }
    }