JavaProject

package com.collabera.mongo;
import java.util.*;

import static org.bson.codecs.configuration.CodecRegistries.fromProviders;
import static org.bson.codecs.configuration.CodecRegistries.fromRegistries;

import org.bson.codecs.configuration.CodecProvider;
import org.bson.codecs.configuration.CodecRegistry;
import org.bson.codecs.pojo.PojoCodecProvider;
import org.bson.types.ObjectId;

import com.mongodb.MongoClient;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.model.Filters;
import com.mongodb.client.model.Updates;
import com.mongodb.client.result.DeleteResult;
import com.mongodb.client.result.UpdateResult;

public class UserMongoDao {
	private MongoClient mongoClient = null;
	private MongoDatabase database = null;
	private MongoCollection<User> collection = null;

	public void connectToMongo() {
		CodecProvider pojoCodecProvider = PojoCodecProvider.builder().
				automatic(true).build();
		CodecRegistry pojoCodecRegistry =
				fromRegistries(MongoClient.getDefaultCodecRegistry(),
						fromProviders(pojoCodecProvider));

		mongoClient = new MongoClient( "localhost" , 27017 );
		database = mongoClient.getDatabase("mydb")
				.withCodecRegistry(pojoCodecRegistry);
		collection = database.getCollection("users", User.class);
	}
	public User findByUserName(String userName) {
		User user = collection.find(
				Filters.eq("userName", userName)).first();
		System.out.println(user);
		return user;
	}
	public User findById(ObjectId id) {
		User user = collection.find(
				Filters.eq("_id", id)).first();
		System.out.println(user);
		return user;
	}

	public List<User> listAllUsers() {
		List<User> users = new ArrayList<User>();
		users = collection.find().into(new ArrayList<User>());
		for(User user:users) {
			System.out.println(user);
		}
		return users;
	}

	public boolean authUser(String username, String password) {

		UserMongoDao uDao = new UserMongoDao();
		boolean flag = false;

		if(uDao.findByUserName(username) != null) {
			if(uDao.findByUserName(username).getPassword() == password) {
				flag = true;
			}
		}
		else {
			System.out.println("Something went wrong!");
		}
		return flag;
	}

	public static void main(String[] args) {
		UserMongoDao userDao = new UserMongoDao();
		userDao.connectToMongo();

		System.out.println("--------- List All Users -------------");
		userDao.listAllUsers();

		System.out.println("--------- Find User By ID -------------");
		userDao.findById(new ObjectId("5dd888779cb58b493f10bcd1"));

		System.out.println("--------- List All Users -------------");
		userDao.listAllUsers();

		System.out.println("--------- Find User -------------");
		userDao.authUser("root", "root");
	}
}