Deep Dive into Spring Data and MongoDB Fabiano Guizellini Modos - - PowerPoint PPT Presentation

Deep Dive into Spring Data and MongoDB

Fabiano Guizellini Modos Software Architect at HBSIS @fmodos

I Java and MongoDB

Why do I love Java?

• Learned Object Oriented

Programming

• Design Patterns, Clean Code, Unit Test
• Saved me from Programming in

Delphi

Why do I love MongoDB?

• Save complex Objects in an easy way
• No more relational database

commands: Create table, Alter Table, etc..

• Open Source

It is not only a Story ...run this in Production in 3 critical systems

Order Invoice

Supermarket

Order Invoice

Supermarket

Deliver ~5k Suppliers Invoice Daily ~4M Events Daily >10M DB Ops/Daily >100k Sales Invoices Daily >500k Events Daily >10M DB Ops/Daily ~35k Transport Invoice Daily ~300k Events Daily >1M DB Ops/Daily Validate Suppliers Invoice Sales Invoice Transport Invoice

Why did we use MongoDB?

• Complex documents and events
• High Concurrency System

Why did we use MongoDB?

• Complex documents and events
• High Concurrency System

Relational Database? SQL?

SQL NOSQL

“Different databases are designed to solve different problems. Using a single database engine for all of the requirements usually leads to non- performant solutions” ― Pramod J. Sadalage, NoSQL Distilled: A Brief Guide to the Emerging World

• f Polyglot Persistence

“Complex applications combine different types of problems, so picking the right language for each job may be more productive than trying to fit all aspects into a single language.” ― Pramod J. Sadalage, NoSQL Distilled: A Brief Guide to the Emerging World

• f Polyglot Persistence

Case Study – Food Recipe System

Class Diagram Table Diagram (SQL) Document Diagram (NoSQL)

• Users should be able to create Dish with a name, description and list of ingredientes
• Users should be able to add Comments to the Dish.

Create

SQL NoSQL INSERT INTO dish (name) VALUES (“White Rice”) INSERT INTO ingredient (name, dish_id) VALUES (“rice”, 1) INSERT INTO ingredient (name) VALUES (“garlic”, 1) INSERT INTO comment (text, user_id, dish_id) VALUES (“This rice is really good”, 1, 1) db.getCollection(‘Dish’).save({name: “White Rice” ingredients : [“rice”, “garlic”], comments : Array[ { text : ‘This rice is really good’ user : { nickname : ‘FoodLover’, email: ‘fabiano@mail.com’ } ] })

Read

SQL NoSQL SELECT d.name, d.description FROM dish d WHERE id=1 SELECT i.name FROM ingredient i WHERE i.dish_id=1 SELECT c.text, u.nickname, u.name FROM comment c, user u WHERE c.user_id = u.id and c.dish_id = 1 db.getCollection(‘Dish’).find({_id : 1})

Update

SQL NoSQL UPDATE user SET nickname = ‘Bryan’ WHERE id=1 db.getCollection(‘User’).update({_id : 1}, {$set : {nickname : ‘Bryan’}})

{name: “White Rice” ingredients : [“rice”, “garlic”], comments : Array[ { text : ‘This rice is really good’ user : { nickname : ‘FoodLover’, email: ‘fabiano@mail.com’ } ]

Data Inconsistency

Delete

SQL NoSQL DELETE FROM ingredient WHERE dish_id=1 DELETE FROM comment WHERE dish_id=1 DELETE FROM dish WHERE id=1 db.getCollection(‘Dish’).remove({_id : 1})

Java MongoDB Driver

Where is the Framework to Map Java Objects and Documents?

Spring Data

Spring Data

“This is an umbrella project which contains many subprojects that are specific to a given database”

• MongoDB
• Neo4j
• Cassandra
• JDBC Extensions
• Redis
• Etc

How do we get started?

• Add this maven configuration to the pom.xml file
• Add the MongoDB config properties to the config file

<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data- mongodb</artifactId> <version>1.10.6.RELEASE</version> </dependency> spring.data.mongodb.host=localhost spring.data.mongodb.port=27017 spring.data.mongodb.database=dish-db

Application Layers

DishController DishService DishMongoRepository

Application Layers

How to create MongoDB Repository?

package com.fmodos.dish.infraestructure.mongodb; import org.springframework.data.mongodb.repository.MongoRepository; import com.fmodos.dish.domain.Dish; public interface DishMongoRepository extends MongoRepository<Dish, String> { }

How to use the MongoDB Repository?

@Service public class DishService { @Autowired DishMongoRepository dishRepository; public void insert(Dish dish) { dishRepository.insert(dish); } public interface DishMongoRepository extends MongoRepository<Dish, String> { } Where is the insert method?

SpringData Repositories

MongoRepository PagingAndSortingRepository CrudRepository Repository DishMongoRepository <extends>

SpringData Repositories

<S extends T> S save(S entity); <S extends T> Iterable<S> save(Iterable<S> entities); long count(); void delete(ID id); void delete(T entity); void delete(Iterable<? extends T> entities); void deleteAll();

dishMongoRepository.delete("id"); List<Dish> listDish = new ArrayList<Dish>(); List<Dish> savedList = dishMongoRepository.save(listDish); long count = dishMongoRepository.count();

SpringData Repositories

T findOne(ID id); boolean exists(ID id); Iterable<T> findAll(); Iterable<T> findAll(Iterable<ID> ids); Iterable<T> findAll(Sort sort); Page<T> findAll(Pageable pageable);

List<Dish> listDish = dishRepository.findAll() Dish dish = dishRepository.findOne(id) Page<Dish> pageDish = dishMongoRepository.findAll( new PageRequest(1, 10));

What about Query Filter?

public interface DishMongoRepository extends MongoRepository<Dish, String> { public List<Dish> findByName(String name); public List<Dish> findByNameAndDateCreatedGreaterThan(String name Date dateCreated); } “Methods should have verb or verb phrase names” Clean Code

What is the magic? DSL – Dynamic Reception

• Handle messages without defining

them in the receiving class

• Build dynamic queries using the

method declaration

Spring Data Query

Keyword Sample Logical result After findByBirthdateAfter(Date date) {"birthdate" : {"$gt" : date}} GreaterThan findByAgeGreaterThan(int age) {"age" : {"$gt" : age}} GreaterThanEqual findByAgeGreaterThanEqual(int age) {"age" : {"$gte" : age}} Before findByBirthdateBefore(Date date) {"birthdate" : {"$lt" : date}} LessThan findByAgeLessThan(int age) {"age" : {"$lt" : age}} LessThanEqual findByAgeLessThanEqual(int age) {"age" : {"$lte" : age}} Between findByAgeBetween(int from, int to) {"age" : {"$gt" : from, "$lt" : to}} In findByAgeIn(Collection ages) {"age" : {"$in" : [ages…​]}} NotIn findByAgeNotIn(Collection ages) {"age" : {"$nin" : [ages…​]}} IsNotNull, NotNull findByFirstnameNotNull() {"firstname" : {"$ne" : null}} IsNull, Null findByFirstnameNull() {"firstname" : null} Like, StartingWith, EndingWith findByFirstnameLike(String name) {"firstname" : name} (name as regex) NotLike, IsNotLike findByFirstnameNotLike(String name) {"firstname" : { "$not" : name }} (name as regex)

Spring Data Query

Containing on String findByFirstnameContaining(String name) {"firstname" : name} (name as regex) NotContaining on String findByFirstnameNotContaining(String name) {"firstname" : { "$not" : name}} (name as regex) Containing on Collection findByAddressesContaining(Address address) {"addresses" : { "$in" : address}} NotContaining on Collection findByAddressesNotContaining(Addr ess address) {"addresses" : { "$not" : { "$in" : address}}} Regex findByFirstnameRegex(String firstname) {"firstname" : {"$regex" : firstname }} (No keyword) findByFirstname(String name) {"firstname" : name} Not findByFirstnameNot(String name) {"firstname" : {"$ne" : name}} IsTrue, True findByActiveIsTrue() {"active" : true} IsFalse, False findByActiveIsFalse() {"active" : false} Exists findByLocationExists(boolean exists) {"location" : {"$exists" : exists }}

MongoDB JSON Based Query

public interface DishMongoRepository extends MongoRepository<Dish, String> { @Query(value="{ 'ingredients' : {$in : ?0 }", fields="{ 'name' : 1}") public List<Dish> findNameByIngredients(List<String> ingredients); }

MongoTemplate Operations

mongoTemplate.upsert(new Query(Criteria.where("name").is("Brazil Food")), Update.update("description", "Really Good Food"), Dish.class) @Autowired MongoTemplate mongoTemplate;

• Upsert - Update or insert a new Document combining the Query and the Update values
• Autowire MongoTemplate
• FindAndModify – Query the Document, update it and return the Updated one

Dish dish = mongoTemplate.findAndModify(new Query(Criteria.where("name").is("Brazil Food")), Update.update("description", "Really Good Food"), Dish.class); “The design goal was to make it as easy as possible to transition between the use of the base MongoDB driver and MongoOperations”

How to combine Repository and MongoTemplate?

interface DishMongoRepository interface MongoRepository interface IDishMongoTemplateRepository class DishMongoTemplateRepository extends extends extends

DishController DishService DishMongoRepository

Application Layers

High Coupling Between Dish Service Businesse Rules and MongoDB

Application Layers

DishController DishService IDishRepository MongoDishRepository JpaRepository <extends> <extends> SQLDishRepository <extends>

Database Resilience – Circuit Breaker

IDishRepository MongoDishRepository SQLDishRepository HystrixRepository <extends>

Demo Lessons Learned

Application Query without Index Query without Projection

Cool features I never used in Production

Full Text Query

Query query = TextQuery.queryText(new TextCriteria().matching("rice")); mongoTemplate.find(query, Dish.class);

Query in the Dish Fields annotated with @TextIndexed(weight=1)

Similar behavior would be to query using OR operator

GeoSpatial – Query Player within Box

Box box = new Box(new Point(-73.99756, 40.73083), new Point(-73.988135, 40.741404)); List<Player> venues = template.find(new Query(Criteria.where("location").withinBox(box)), Player.class); class Player { private double[] location; }

GeoSpatial – Query by distance

Point location = new Point(-73.99171, 40.738868); NearQuery query = NearQuery.near(location).maxDistance(new Distance(10, Metrics.MILES)); GeoResults<SinglePerson> = operations.geoNear(query, SinglePerson.class);

Summary

• Document Oriented Modelling
• Native CRUD operations in MongoDB
• Application Layers
• SpringData Repositories
• SpringData Query
• MongoTemplate Operations
• Lessons Learned in Production
• FullTextQuery
• GeoSpatialQuery

Thank you! @fmodos