An Introduction to Spring Data

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An Introduction to Spring Data

Oliver Gierke - SpringSource, a division of VMware


Oliver Gierke

Spring DataCore/JPA/MongoDB

[email protected]

2

mailto:[email protected]

mailto:[email protected]

http://www.olivergierke.de

http://www.olivergierke.de

What to expect?



Why?


Why?

How?


Why?

How?

What?

5

A Developer‘s View

What to expect?NOT!


What to expect? NOT!

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Retrospect

Relational databases

Cloud

Scaling

Data structures


(No)SQLRedis

Riak

MongoDB

Cassandra

CouchDB

Neo4JHBase

SimpleDB

OrientDB

MembaseHibari Voldemort

Sones

Graphs

Documents

Column families

Key Value

Forest for the woods?

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A Developer‘s View


There‘s someSpring for that!

Spring Data


"… provide a familiar and consistent Spring-based programming model while not over-abstracting custom traits of the specific store.


JPAJDBC


JPAJDBC


JPAJDBC


JPAJDBC


JPAJDBC


JPAJDBC

Building blocks

Spring

Mapping

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Entity mapping

@Documentclass Person {

@Id private BigInteger id;@Indexed private String firstname, lastname;@Field(„email“) private String emailAddress;@DBRef private Set<Person> colleagues;

public Person(String firstname) { … }

@PersistenceConstructorpublic Person(String firstname, String lastname) { … }

…}

Templates

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MongoOperations / -Template

public interface MongoOperations {

// Generic callback-accepting methods <T> T execute(DbCallback<T> action);

<T> T execute(Class<?> entityClass, CollectionCallback<T> action);<T> T execute(String collectionName, CollectionCallback<T> action);

// Higher level access methods<T> List<T> find(Query query, Class<T> entityClass);void save(Object objectToSave, String collectionName);WriteResult updateFirst(Query query, Update update, Class<?>

entityClass);

// Geo API<T> GeoResults<T> geoNear(NearQuery near, Class<T> entityClass);

}

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MongoTemplate usage

// Setup infrastructureMongo mongo = new Mongo();MongoDbFactory factory = new SimpleMongoDbFactory(mongo, „foo“);MongoTemplate template = new MongoTemplate(factory);

// Create and save entityPerson dave = new Person(„Dave“, „Matthews“);dave.setEmailAddress(„[email protected]“);template.save(person);

// Query entityQuery query = new Query(new Criteria(„emailAddress“)

.is(„[email protected]“));assertThat(template.find(query), is(dave));

Repositories

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Repositories

public interface PersonRepository extends Repository<Person, BigInteger>{

// Finder for a single entityPerson findByEmailAddress(String emailAddress);

// Finder for multiple entitiesList<Person> findByLastnameLike(String lastname);

// Finder with paginationPage<Person> findByFirstnameLike(String firstname, Pageable page);

// Geospatial queriesList<Person> findByLocationNear(Point location, Distance distance);GeoResults<Person> findByLocationNear(Point location);

}

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Repositories usage

<mongo:repositories base-package=„com.acme.repositories“ />

@Componentpublic class MyClient {

@Autowiredprivate PersonRepository repository;

public List<Person> doSomething() {

Point point = new Point(43.7, 48.8);Distance distance = new Distance(200, Metrics.KILOMETERS);return repository.findByLocationNear(point, distance);

}}

Repositories

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Querydsl

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MongoTemplate usage

public interface QueryDslPredicateExecutor<T> {T findOne(Predicate predicate);List<T> findAll(Predicate predicate);

}

public interface PersonRepository extends Repository<Person, ObjectId>,QueryDslPredicateExecutor { … }

QPerson $ = QPerson.person;BooleanExpression left = $.lastname.contains(„eth“);BooleanExpression right = $.firstname.is(„Carter“);

List<Person> result = repository.findAll(left.or(right));assertThat(result.size(), is(2));assertThat(result, hasItems(dave, carter));

JPA

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JPA entity mapping

@Entityclass Person {

@Id@GeneratedValue(strategy=GenerationType.AUTO)private BigInteger id;private String firstname, lastname;

@Column(name=„email“) private String emailAddress;

@OneToMany private Set<Person> colleagues;

}

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Repository

public interface PersonRepository extends Repository<Person, BigInteger>{

// Finder for a single entityPerson findByEmailAddress(String emailAddress);

// Finder for multiple entitiesList<Person> findByLastnameLike(String lastname);

// Finder with paginationPage<Person> findByFirstnameLike(String firstname, Pageable page);

}

<jpa:repositories base-package=„com.acme.repositories“ />

Wrap up

• Sophisticated mapping support• Templates• Repositories• Querydsl• Spring namespace• Geospatial support• Cross-store persistence

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Wrap up

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Upcoming Talks

• Today– 10:15 - Spring Data Gemfire– 12:45 - Spring Data MongoDB & CloudFoundry– 4:30 - Spring Data Neo4J

• Thursday– 8:30 - Spring Data JPA & Repositories– 10:15 - Polyglot persistence

• Friday– 8:30 - SQLFire


Play with it


Participate


Spread the word

Questions?

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Resources

• www.springframework.org/spring-data• github.com/SpringSource/spring-data-mongodb• http://www.se-radio.net/2010/07/episode-165-nosql-

and-mongodb-with-dwight-merriman• http://kkovacs.eu/cassandra-vs-mongodb-vs-

couchdb-vs-redis

http://www.springframework.org/spring-data

http://www.springframework.org/spring-data

https://github.com/SpringSource/spring-data-mongodb

https://github.com/SpringSource/spring-data-mongodb

http://www.se-radio.net/2010/07/episode-165-nosql-and-mongodb-with-dwight-merriman/






http://kkovacs.eu/cassandra-vs-mongodb-vs-couchdb-vs-redis




• Building blocks - http://www.sxc.hu/photo/297189• Columns - http://www.sxc.hu/photo/1033540• Dilemma - http://www.sxc.hu/photo/125069• Forest - http://www.sxc.hu/photo/1274066• Glasses - http://www.sxc.hu/photo/696003• Mapping - http://www.sxc.hu/photo/1253374• Nails - http://www.sxc.hu/photo/933587• Questions - http://www.sxc.hu/photo/860327• Repository - http://www.sxc.hu/photo/1042408• Retrospect - http://www.sxc.hu/photo/921297• Spreadsheet - http://www.sxc.hu/photo/338505• Spring - http://www.sxc.hu/photo/1291358• Umbrella - http://www.sxc.hu/photo/1364634• Template - http://www.sxc.hu/photo/619819• Wrap up - http://www.sxc.hu/photo/922227

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Sources

http://www.sxc.hu/photo/297189






























Technology

An Introduction to Spring Data