MongoDBHelper

import java.util.ArrayList;
import java.util.List;

import org.bson.Document;
import org.bson.conversions.Bson;

import com.mongodb.BasicDBObject;
import com.mongodb.MongoClient;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;

public class MongoDBHelper {

    public MongoClient connection;
    public MongoDatabase database;
    public MongoCollection<Document> collection;

    public MongoDBHelper(String host, int port, String database, String collection) {
        this.setConnection(host, port);
        this.setDatabase(database);
        this.setCollection(collection);
    }

    public MongoClient getConnection() {
        return connection;
    }

    public void setConnection(MongoClient connection) {
        this.connection = connection;
    }

    public void setConnection(String host, int port) {
        this.connection = new MongoClient(host, port);
    }

    public MongoDatabase getDatabase() {
        return database;
    }

    public void setDatabase(MongoDatabase database) {
        this.database = database;
    }

    public void setDatabase(String database) {
        this.database = this.getConnection().getDatabase(database);
    }

    public MongoCollection<Document> getCollection() {
        return collection;
    }

    public void setCollection(MongoCollection<Document> collection) {
        this.collection = collection;
    }

    public void setCollection(String collection) {
        this.collection = this.getDatabase().getCollection(collection);
    }

    private List<Document> executeSelect(Bson query) {
        List<Document> records = (List<Document>) this.getCollection().find(query).into(new ArrayList<Document>());
        return records;
    }

    public List<Document> getFieldValueEqualTo(String field, String value) {
        List<Document> records = executeSelect(new BasicDBObject(field, value));
        return records;
    }

    public List<Document> getFieldValueNotEqualTo(String field, String value) {
        List<Document> records = executeSelect(new BasicDBObject(field, new BasicDBObject("$ne", value)));
        return records;
    }

    public static void printRecords(List<Document> records) {
        for (Document record : records) {
            System.out.println(record.toJson());
        }
    }
}