learning java is this code correct

I am new to java programming and to help me learn I created a simple telephone address book. the code runs as expected but I would be interested to here from more advanced programmers if they think I should do it differently.

    import com.mongodb.MongoClient;
    import com.mongodb.MongoException;
    import com.mongodb.DB;
    import com.mongodb.DBCollection;
    import com.mongodb.BasicDBObject;
    import com.mongodb.DBCursor;

    import java.net.UnknownHostException;
    import java.util.Scanner;

    import org.bson.types.ObjectId;

    public class MongodbPhonebook {
        public static void main(String[] args) {
            boolean boolContinue = true;
            String stringCommand;
            Scanner input = new Scanner(System.in);

            try {
                MongoClient mongoClient = new MongoClient();
                DB db = mongoClient.getDB( "myphonelist" );
                DBCollection coll = db.getCollection("myphonelist");



                do {
                    System.out.println("Enter command (add, find, show, quit): ");
                    stringCommand = input.nextLine();
                    if(stringCommand.equals("quit")){
                        boolContinue = false;
                    }
                    else if(stringCommand.equals("show")){
                        displayAll(coll);
                    }
                    else if(stringCommand.equals("add")){
                        insertNumber(coll);
                    }
                    else if(stringCommand.equals("find")){
                        findNumber(coll);
                    }
                    else {
                        System.out.println("Unknown command!");
                    }
                } while(boolContinue == true);
            }
            catch (UnknownHostException e) {
                e.printStackTrace();
            }
            catch (MongoException e) {
                e.printStackTrace();
            } 
        }

        public static void displayAll(DBCollection collDisplay) {
            DBCursor cursor = collDisplay.find();
            try {
                while(cursor.hasNext()) {
                    System.out.println(cursor.next());
                }
            } finally {
                cursor.close();
            }   
            return;
        }

        public static void insertNumber (DBCollection collInsert) {
            Scanner input = new Scanner(System.in);
            ObjectId stringID;
            String stringName = "";
            String stringNumber = "";
            System.out.println("Enter name: ");
            stringName = input.nextLine();
            System.out.println("Enter number: ");
            stringNumber = input.nextLine();
            BasicDBObject doc = new BasicDBObject("name", stringName).
                    append("number", stringNumber);
            collInsert.insert(doc);
            stringID = (ObjectId)doc.get( "_id" );
            System.out.println("Result: " + stringID.toString());
            return;
        }

        public static void findNumber (DBCollection collFind) {
            Scanner input = new Scanner(System.in);
            String stringName = "";
            System.out.println("Enter name: ");
            stringName = input.nextLine();
            BasicDBObject query = new BasicDBObject("name", stringName);

            DBCursor cursor = collFind.find();
            cursor = collFind.find(query);

            try {
                while(cursor.hasNext()) {
                    System.out.println("found " + cursor.next());
                }
            } finally {
                cursor.close();
            }
        }
    }

Here is the code after changing it to use a switch statement:

import com.mongodb.MongoClient;
import com.mongodb.MongoException;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.BasicDBObject;
import com.mongodb.DBCursor;

import java.net.UnknownHostException;
import java.util.Scanner;

import org.bson.types.ObjectId;

public class MongodbPhonebook {
    private MongoClient mongoClient;
    private DB db;
    private DBCollection coll;

    public static void main(String[] args) {
        MongodbPhonebook mpb = new MongodbPhonebook();
        mpb.doLoop();
    }

    public void doLoop() {

        boolean boolContinue = true;
        Scanner input = new Scanner(System.in);

        try {
            this.mongoClient = new MongoClient();
            this.db = mongoClient.getDB("myphonelist");
            this.coll = db.getCollection("myphonelist");

            do {
                System.out.println("Enter command (add, find, show, quit): ");
                String stringCommand = input.nextLine();
                switch (stringCommand) {
                case "quit":
                    boolContinue = false;
                    break;
                case "show":
                    displayAll(this.coll);
                    break;
                case "add":
                    insertNumber(this.coll);
                    break;
                case "find":
                    findNumber(this.coll);
                    break;
                default:
                    System.out.println("Unknown command!");
                    break;
                }
            } while (boolContinue);
        } catch (UnknownHostException e) {
            e.printStackTrace();
        } catch (MongoException e) {
            e.printStackTrace();
        }

    }

    public void displayAll(DBCollection collDisplay) {
        DBCursor cursor = collDisplay.find();
        try {
            while (cursor.hasNext()) {
                System.out.println(cursor.next());
            }
        } finally {
            cursor.close();
        }
    }

    public void insertNumber(DBCollection collInsert) {
        Scanner input = new Scanner(System.in);
        ObjectId stringID;
        System.out.println("Enter name: ");
        String stringName = input.nextLine();
        System.out.println("Enter number: ");
        String stringNumber = input.nextLine();
        BasicDBObject doc = new BasicDBObject("name", stringName).append(
                "number", stringNumber);
        collInsert.insert(doc);
        stringID = (ObjectId) doc.get("_id");
        System.out.println("Result: " + stringID.toString());
    }

    public void findNumber(DBCollection collFind) {
        Scanner input = new Scanner(System.in);
        System.out.println("Enter name: ");
        String stringName = input.nextLine();
        BasicDBObject query = new BasicDBObject("name", stringName);

        DBCursor cursor = collFind.find();
        cursor = collFind.find(query);

        try {
            while (cursor.hasNext()) {
                System.out.println("found " + cursor.next());
            }
        } finally {
            cursor.close();
        }
    }
}