GraphAware®

Build Spring Data Neo4j 4 Applications like a Superhero

graphaware.com

@graph_aware, @luannem

Luanne Misquitta

Most active Spring project

Convenient data access to (No)SQL databases

Consistent API’s

Mapping POJOs, Template, Repositories

Neo4j, JPA, MongoDB, Redis, CouchBase & more

Spring Data

GraphAware®

Focus on performance

Based on a pure Java OGM [Neo4j-OGM]

3 Drivers available to connect to Neo4j

HTTP

Embedded

Bolt

Spring Data Neo4j 4.1

GraphAware®

Object Graph Mapping from any Java or JVM-based application

“Vampire” metadata scanning (no reflection!)

“Smart” object mapping

Mapping contexts tied to Session lifetimes

Application

HTTP session/request etc.

Support for default and bespoke type conversions

Repositories, Neo4jTemplate [SDN]

Custom Queries, Derived Finders [SDN]

Transactional Support

Features

GraphAware®

Persistence horizon (depth) indicates how many relationships should be traversed in the graph when loading or saving data

Default loading depth is 1

Default persistence depth is -1

Variable Depth Persistence

GraphAware®

It’s a bird, it’s a plane, it’s a superhero graph!

Node Entities - Character

GraphAware®

@NodeEntity(label = "Character")

public class Character {

@GraphId Long graphId;

…

private Long id;

private String name;

private String alias;

private String realName;

Node Entities - Relationships

GraphAware®

public class Character {…@Relationship(type = "ALLY_OF", direction = Relationship.UNDIRECTED)

@Relationship(type = "ENEMY_OF", direction = Relationship.UNDIRECTED)

@Relationship(type = "MEMBER_OF")

@Relationship(type = "STARS", direction = Relationship.INCOMING)

Set<Character> allies = new HashSet<>();

Set<Character> enemies = new HashSet<>();

Set<Team> teams = new HashSet<>();

Set<Role> roles = new HashSet<>();

Set<Game> gamesFeaturedIn = new HashSet<>();

@Relationship(type = "FEATURED_IN")

@Relationship(type = "FEATURED_IN")

Set<Comic> comicsFeaturedIn = new HashSet<>();

Node Entities - Hierarchy

GraphAware®

public class Villain extends Character{

…

}

public class Hero extends Character {

… }

@NodeEntity(label = "Hero")

@NodeEntity(label = "Villain")

Node Entities - Team

GraphAware®

@NodeEntity(label = "Team")

public class Team {

@GraphId private Long graphId;

private Long id;

private String name;

private String operationsBase;

@Relationship(type = "MEMBER_OF",

direction = "INCOMING")

private Set<Character> members = new HashSet<>();

public Team() {

}

Node Entities - Comic

GraphAware®

@NodeEntity(label = "Comic")

private Long id;

private String title;

private String author;

private String artist;

private boolean available;

private Binding binding;

@DateLong

private Date onSaleDate;

@Relationship(type = "FEATURED_IN", direction = Relationship.INCOMING)

private Set<Character> characters = new HashSet<>();

public enum Binding {

SOFT,

LEATHER,

CLOTH,

HARD

}

public class Comic {

@GraphId private Long graphId;

Node Entities - Game

GraphAware®

@NodeEntity(label = "Game")

public class Game {

@Graphid private Long graphId;

private Long id;

private String title;

private int year;

private String publisher;

private Rating rating;

private Set<Platform> platforms;

@Relationship(type = "FEATURED_IN",

direction = Relationship.INCOMING)

private Set<Character> characters = new HashSet<>();

public enum Platform {

PC,

WII,

XBOX_360,

PLAYSTATION_3

}

Node Entities

GraphAware®

@Convert(UrlConverter.class)

private URL imdbUrl;

@Relationship(type = "STARS")

private Set<Role> stars;

public class UrlConverter implements

AttributeConverter<URL, String> {

@Override

public String toGraphProperty(URL value) {

return value == null? null : value.toString();

}

@Override

public URL toEntityAttribute(String value) {

try {

return new URL(value);

} catch (MalformedURLException e) {

e.printStackTrace();

}

return null;

} }

@NodeEntity(label = "Movie")

public class Movie {

@GraphId private Long graphId;

private Long id;

private String title;

private int year;

private Rating rating;

Relationship Entities

GraphAware®

@RelationshipEntity(type = "STARS")

public class Role {

private Long id;

@StartNode private Movie movie;

@EndNode private Character character;

private String actor;

Repositories

GraphAware®

public interface CharacterRepository<T extends Character> extends GraphRepository<T> {

List<T> findByNameLike(String keyword);

@Query(" MATCH (c:Character) WHERE ID(c)={characterId} " +

"OPTIONAL MATCH (c)-[:ALLY_OF|ENEMY_OF]-(other) " +

"WITH c, collect(other) as others " +

"OPTIONAL MATCH (c)-[:MEMBER_OF|FEATURED_IN]->

()<-[:MEMBER_OF|FEATURED_IN]-(teamMember) " +

"WITH c, others + collect(teamMember) as othersWithTeam " +

"OPTIONAL MATCH (c)<-[:STARS]-()-[:STARS]->(actors) " +

"WITH othersWithTeam + collect(actors) as allOthers " +

"UNWIND allOthers as related " +

"WITH count(*) as count, related " +

"RETURN related ORDER BY count DESC")

List<Character> findRelatedCharacters(@Param("characterId") Long id);

Repositories

GraphAware®

public interface HeroRepository extends CharacterRepository<Hero> {

}

public interface VillainRepository extends CharacterRepository<Villain>{

}

Services

GraphAware®

@Service

public class CharacterService {

@Autowired CharacterRepository<Character> characterRepository;

@Autowired HeroRepository heroRepository;

@Autowired VillainRepository villainRepository;

public List<CharacterSummary> searchHeroesByKeyword(String keyword) {

return summarizeCharacter(heroRepository.findByNameLike(getKeywordParam(keyword));

}

public List<Character> findRelatedCharacters(Long id) {

return characterRepository.findRelatedCharacters(id);

}

public Character getById(Long id) {

return characterRepository.findById(id);

}

…

}

Controller

GraphAware®

@RestController

@RequestMapping("/api/")

public class CharacterController {

@Autowired CharacterService characterService;

@RequestMapping(value = "characters/{id}", method = RequestMethod.GET)

public Character getCharacterById(@PathVariable("id") Long id) {

return characterService.getById(id);

}

@RequestMapping(value = "characters/{id}/related", method = RequestMethod.GET)

public List<Character> getRelatedCharacters(@PathVariable("id") Long id) {

return characterService.findRelatedCharacters(id);

}

SDN 4.1 / Neo4j OGM Driver Configuration

GraphAware®

driver=org.neo4j.ogm.drivers.http.driver.HttpDriver

URI=http://neo4j:neo@localhost:7474

Auto configure with ogm.properties

Java Configuration

Components.configuration()

.driverConfiguration()

.setDriverClassName("org.neo4j.ogm.drivers.http.driver.HttpDriver")

.setURI("http://user:password@localhost:7474")

SDN 4.1 Neo4j Configuration

GraphAware®

@Configuration

@ComponentScan("com.graphaware.superhero")

@EnableAutoConfiguration

@EnableTransactionManagement

@EnableNeo4jRepositories("com.graphaware.superhero.repository")

public class Application extends Neo4jConfiguration {

public static void main(String[] args) {

SpringApplication.run(Application.class, args);

}

…

SDN 4.1 Neo4j Configuration

GraphAware®

…

public class Application extends Neo4jConfiguration {

@Override

@Bean

public SessionFactory getSessionFactory() {

return new SessionFactory("com.graphaware.superhero.domain");

}

@Override

@Bean

@Scope(value = "session", proxyMode = ScopedProxyMode.TARGET_CLASS)

public Session getSession() throws Exception {

return super.getSession();

}

Up, up and away!

GraphAware®

mvn clean spring-boot:run

Documentation: http://docs.spring.io/spring-data/neo4j/docs/current/reference/html/

Code: https://github.com/spring-projects/spring-data-neo4j

Sample Applications: http://github.com/neo4j-examples?query=sdn4

Where to find stuff

GraphAware®

Where to find us

GraphAware®

Luanne Misquitta

Adam George

Michal “Batman” Bachman

Vince Bickers

Getting Help

StackOverflow (spring-data-neo4j-4, neo4j-ogm)

Slack: neo4j-users (neo4j-sdn)

Email the team: spring-data-neo4j@neotechnology.com

Raise issues: https://jira.spring.io/browse/DATAGRAPH

Twitter: Follow @graph_aware for pro tips

Blog: http://graphaware.com/blog

You’re a Graph Hero!

www.graphaware.com@graph_aware

Thank you

GraphAware®