Kotlin exercise 1: Connect to MongoDB -part 2-

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In the first part of this exercise we have seen how connect to a MongoDb with Java. Now that is clear how the connection can be performed, we can try to do the same with Kotlin.
Ok, no waste other time, start coding:


import com.mongodb.BasicDBObject
import com.mongodb.MongoClient
import com.mongodb.MongoException
import java.net.UnknownHostException
import java.util.*

/**
 * Created by Claudio on 01/05/16.
 * This is a main to test mongoDB connection in kotlin
 */

fun main(args: Array<String>) {

    try
    {
        val mongo = MongoClient("localhost", 27017)

        val db = mongo.getDB("testDB")

        val table = db.getCollection("person")

        //Reflection example
        val person = Person("Jon","Doe",20);

        val data = person.javaClass;


        //Insert document
        val document = BasicDBObject()
        document.put("name", "mkyong")
        document.put("age", 30)
        document.put("createdDate", Date())
        table.insert(document)

        /**** Find and display ****/
        val searchQuery = BasicDBObject();
        searchQuery.put("name", "mkyong");

        val cursor = table.find(searchQuery);

        while (cursor.hasNext()) {
            System.out.println(cursor.next());
        }
    }
    catch (e: UnknownHostException) {
        e.printStackTrace ( );
    } catch (e: MongoException) {
        e.printStackTrace();
}

}
  

Sorry but the kotlin code isn’t highlighted

How we see the code is similar with Java example and the output is equal:

Schermata 2016-05-04 alle 21.10.01

This code can be converted from Java code with the intellij IDE function called: “Convert java code to kotlin code”. This can be reached from the search tool or vith copy and paste of java code to kotlin file:

Cattura

For exercise the “Main.kt” code is was written from scratch.

In this little exercice I learned how connect to MongoDb and how code something more difficult to “hello world” in Kotlin.

A little step for mankind, a big step for a developer!

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