Spring Data MongoDB Maciej Walkowiak

Agenda NoSQL MongoDB Spring Data Spring Data MongoDB

NoSQL

NoSQL

key-value store document oriented column family based graph NoSQL

NoSQL schemaless non-relational cluster friendly Common characteristics

No content

document oriented full index support auto-sharding BSON map reduce non-transactional document linking geospatial indexes

post collection entry author collection entry { "_id" : ObjectId("5146227a0364038863be7514"), "title" : "post title", "content" : "hello jug", "createdAt" : ISODate("2013-03-17T20:07:22.455Z"), "tags" : [ "mongodb", "jug", "szczecin" ], } { "_id" : ObjectId("514622790364038863be7513"), "name" : "maciej walkowiak", }

post collection entry linked with author { "_id" : ObjectId("5146227a0364038863be7514"), "title" : "post title", "content" : "hello world coders", "createdAt" : ISODate("2013-03-17T20:07:22.455Z"), "tags" : [ "mongodb", "jug", "szczecin" ], "author" : DBRef("author", ObjectId("514622790364038863be7513")) }

post collection entry with embedded author { "_id" : ObjectId("51476f8d03646a6b3186f081"), "title" : "post title", "content" : "hello world coders", "createdAt" : ISODate("2013-03-18T19:48:29.667Z"), "tags" : [ "mongodb", "jug", "szczecin" ], "author" : { "name" : "maciej walkowiak", "email" : "walkowiak.maciej@yahoo.com" } }

db.post.find(); db.post.findOne({ _id: ObjectId("5146227a0364038863be7514") }); db.place.find({ coords : { $near: [-110,32], $maxDistance : 10/111.12 } }) db.post.find({ tags: "szczecin", createdAt: { $gt : ISODate("2013-03-01") } })

MongoDB + Java

MongoDB + Java

MongoDB + Java Morphia Spring Data MongoDB

Spring Data

Spring Data Same programming model for many databases simple things simple, complex things possible One API to rule them all - nope reduce amount boilerplate code

Spring Data Same programming model for many databases simple things simple, complex things possible One API to rule them all - nope reduce amount boilerplate code

JPA MongoDB Redis Hadoop Neo4j HBase Spring Data Supported databases

mapping template repositories Map Reduce QueryDSL Cross-Store Spring Data

Mapping { "_id" : ObjectId("5149471a0364c59b4e743584"), "_class" : "pl.maciejwalkowiak.jug.mongo.Post", "post_title" : "post title", "content" : "hello world coders", "createdAt" : ISODate("2013-03-20T05:20:26.985Z"), "comments" : [ ], "tags" : [ "mongodb", "jug", "szczecin" ], "version" : 0, "author" : DBRef("user", ObjectId("5149471a0364c59b4e743583")) }

Mapping @Document public class Post { @Id private ObjectId id; @DBRef private User author; @Field("post_title") private String title; private String content; @CreatedDate private DateTime createdAt; private List comments = new ArrayList(); private Set tags = new HashSet(); @Version private Integer version; ... } { "_id" : ObjectId("5149471a0364c59b4e743584"), "_class" : "pl.maciejwalkowiak.jug.mongo.Post", "post_title" : "post title", "content" : "hello world coders", "createdAt" : ISODate("2013-03-20T05:20:26.985Z"), "comments" : [ ], "tags" : [ "mongodb", "jug", "szczecin" ], "version" : 0, "author" : DBRef("user", ObjectId("5149471a0364c59b4e743583")) }

Template interface MongoOperations { T findOne(Query query, Class entityClass); T findAndModify(Query query, Update update, Class entityClass); long count(Query query, String collectionName); void save(Object objectToSave); WriteResult updateMulti(Query query, Update update, Class> entityClass); void remove(Query query, Class entityClass); GroupByResults group(String inputCollectionName, GroupBy groupBy, Class entityClass); MapReduceResults mapReduce(Query query, String inputCollectionName, String mapFunction, String reduceFunction, Class entityClass); CommandResult executeCommand(DBObject command); ... }

Repositories DAO in DDD CrudRepository PagingAndSortingRepository declarative find methods

Repositories public interface UserRepository extends PagingAndSortingRepository{ User findByName(String name); List findByNameLike(String name, Pageable pageable); }

Repositories public interface UserRepository extends PagingAndSortingRepository{ User findByName(String name); List findByNameLike(String name, Pageable pageable); } public interface PostRepository extends CrudRepository, PostRepositoryCustom { @Query("{$where : 'this.content.length > 20'}") List findLongPosts(); @Query("{$where : 'this.content.length > ?0'}") List findPostsLongerThan(int length); }

Repositories public interface UserRepository extends PagingAndSortingRepository{ User findByName(String name); List findByNameLike(String name, Pageable pageable); } @Repository public class PostRepositoryImpl implements PostRepositoryCustom { @Autowired private MongoOperations mongoOperations; public Post foo() { return mongoOperations.findOne(Query.query(Criteria.where("title").exists(true)), Post.class); public interface PostRepository extends CrudRepository, PostRepositoryCustom { @Query("{$where : 'this.content.length > 20'}") List findLongPosts(); @Query("{$where : 'this.content.length > ?0'}") List findPostsLongerThan(int length); }

Map Reduce // map function () { emit(this.description, 1); }

Map Reduce // reduce function (key, values) { var sum = 0; for (var i = 0; i < values.length; i++) sum += values[i]; return sum; } // map function () { emit(this.description, 1); }

Map Reduce MapReduceResults results = mongoOperations.mapReduce("collectionName", "classpath:map.js", "classpath:reduce.js", ValueObject.class); // reduce function (key, values) { var sum = 0; for (var i = 0; i < values.length; i++) sum += values[i]; return sum; } // map function () { emit(this.description, 1); }

QueryDSL Type-Safe criteria API

QueryDSL @Generated("com.mysema.query.codegen.EntitySerializer") public class QPost extends EntityPathBase { private static final long serialVersionUID = -1782980951; private static final PathInits INITS = PathInits.DIRECT; public static final QPost post = new QPost("post"); public final QUser author; public final ListPath comments = this.createList("comments", Comment.class, QComment.class, PathInits.DIRECT); public final StringPath content = createString("content"); public final org.joda.time.QDateTime createdAt; public final org.bson.types.QObjectId id; Type-Safe criteria API

QueryDSL postRepository.findAll(QPost.post.content.contains("hello"))); @Generated("com.mysema.query.codegen.EntitySerializer") public class QPost extends EntityPathBase { private static final long serialVersionUID = -1782980951; private static final PathInits INITS = PathInits.DIRECT; public static final QPost post = new QPost("post"); public final QUser author; public final ListPath comments = this.createList("comments", Comment.class, QComment.class, PathInits.DIRECT); public final StringPath content = createString("content"); public final org.joda.time.QDateTime createdAt; public final org.bson.types.QObjectId id; Type-Safe criteria API

Demo

MongoDB as a Service 0.5GB for free

Q&A

Contact walkowiak.maciej@yahoo.com @MaciejWalkowiak http://maciejwalkowiak.pl/