MongoDB via Morphia in Spark Java

Posted By: Todd Sharp on 4/7/2017 2:05 GMT

Tagged: Groovy, Java, MongoDB, Morphia, Spark Java

The latest journey in my quest to see just how many new technologies and frameworks I can learn in one week involves Morphia. Morphia is a "Java Object Document Mapper for MongoDB". In other words, it let's us map our POJOs and POGOs to MongoDB Documents and persist them in MongoDB.

Right, so, on to the codes. To get started with Morphia declare a dependency as such:

compile group: 'org.mongodb.morphia', name: 'morphia', version: '1.3.1'

Obviously you'll need to make sure you've got access to a running instance of MongoDB before you try to connect/persist to it. Next, create a domain class - we'll call this one Person:

	package codes.recursive.domain

	import groovy.transform.ToString
	import org.bson.types.ObjectId
	import org.mongodb.morphia.annotations.Entity
	import org.mongodb.morphia.annotations.Id

	@Entity("person")
	@ToString(includeNames = true)
	class Person {
	@Id
	ObjectId id
	String firstName
	String lastName
	}

view raw Person.groovy hosted with ❤ by GitHub

We've annotated this domain class with @Entity and the ID with @Id as required by the framework. To make things a bit more realistic, I've wrapped some common functionality for dealing with a Person in a PersonService. The service will handle getting a reference to the framework and the datastore (I'd probably include that in an abstract service in a real application) and has a save(), list() and findById() method. Standard stuff:

	package codes.recursive.service

	import codes.recursive.domain.Person
	import com.mongodb.MongoClient
	import org.bson.types.ObjectId
	import org.mongodb.morphia.Datastore
	import org.mongodb.morphia.Morphia

	class PersonService {
	Morphia _morphia
	Datastore _datastore

	def getMorphia() {
	if( !_morphia ) {
	_morphia = new Morphia()
	_morphia.mapPackage("codes.recursive.domain");
	}
	return _morphia
	}

	def getDatastore() {
	if( !_datastore ) {
	_datastore = morphia.createDatastore(new MongoClient("localhost", 27017), "mongodb");
	_datastore.ensureIndexes()
	}
	return _datastore
	}

	def save(Person person) {
	datastore.save( person )
	}

	def list() {
	def q = datastore.createQuery(Person.class)
	return q.asList()
	}

	def findById(String id){
	def q = datastore.createQuery(Person.class)
	return q.filter("id", new ObjectId(id)).asList()?.first()
	}
	}

view raw PersonService.groovy hosted with ❤ by GitHub

Next we'll create a simple route in Spark Java to interact with our PersonService, create and persist a new Person if necessary and return a list of Persons to our view.

	get "/mophia", { req, res ->
	def model = [:]
	def person = personService.findById('58e46f2a5b21434c8b592665')
	if (!person) {
	person = new Person(firstName: 'Foo', lastName: 'Manchu')
	personService.save(person)
	}

	model << [people: personService.list()]
	return engine.render(new ModelAndView(commondModel() << model, "morphia"))
	}

view raw Bootstrap.groovy hosted with ❤ by GitHub

And finally, the view code if you're dying to see that:

	<!DOCTYPE html SYSTEM "http://www.thymeleaf.org/dtd/xhtml1-strict-thymeleaf-4.dtd">
	<html xmlns:layout="http://www.ultraq.net.nz/thymeleaf/layout"
	layout:decorate="~{fragments/main}" th:with="nav=${menu}">

	<head>
	<title>Thymeleaf Layout Page</title>
	</head>

	<body>

	<div layout:fragment="content">
	<table class="table table-bordered">
	<tr>
	<th>ID</th>
	<th>First</th>
	<th>Last</th>
	</tr>
	<tr th:each="person : ${people}">
	<td th:text="${person.id}"></td>
	<td th:text="${person.firstName}"></td>
	<td th:text="${person.lastName}"></td>
	</tr>
	</table>
	</div>

	</body>
	</html>

view raw morphia.html hosted with ❤ by GitHub

Which results in the following:

And that's simple object based persistence in MongoDB via a Spark Java application.

Image by jplenio from Pixabay

recursive.codes

recursive.codes

recursive.codes

MongoDB via Morphia in Spark Java

Posted By: Todd Sharp on 4/7/2017 2:05 GMT

Tagged: Groovy, Java, MongoDB, Morphia, Spark Java

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