Java 10: Bridging the Gap Between Database and Stream. Per Minborg, CTO Speedment, Inc. github.com/minborg Speedment, Inc.

Transcription

1 Java 10: Bridging the Gap Between Database and Stream Per Minborg, CTO Speedment, Inc. github.com/minborg

2 Oracle Java Magazine Article

3 Why Should I Need to Use SQL?

4 JShell Demo Sakila Open Source Film Database for MySQL Product Presentation #1 TOOLSpeedment TO CREATEEnterprise SUPERFAST DATABASE APPLICATIONS Speedment,Inc. Inc Speedment,

5 SQL vs. Stream Operations SELECT * FROM FILM WHERE RATING = PG-13 films.stream().filter(film.rating.equal(rating.pg13))

6 Comparison Between SQL and Stream Operations SQL FROM stream() COUNT count() LIMIT limit() DISTINCT distinct() SELECT map() WHERE filter() HAVING filter() JOIN flatmap() or map() UNION concat(s0, s1).distinct() ORDER BY sorted() OFFSET skip() GROUP BY collect(groupingby()) Java Stream Operations

7 Why We Developed Speedment Creating a new DB application took hours Too much boilerplate ORM code Mixing SQL and Java Slow...

8 Speedment Open Source Project Pure Java for entire application Type safety Lazy evaluation of stream Apache 2 license ithub ost p 3rd m va O a J r a opul ng RM o

9 Users From All Over the World

10 How It Works Connects seamlessly to a database Lazily pulls data as streams are consumed Stream introspect its own pipeline before it starts Operations such as filter() and sorted() can be moved from the stream s pipeline and merged into a SQL query

11 Both Streams and SQL Have Declarative Constructs films.stream().filter(film.rating.equal(rating.pg13)) SELECT * FROM FILM WHERE RATING = PG-13

12 Database Collations vs. Java films.stream().filter(film.rating.equal(rating.pg13)) SELECT * FROM FILM WHERE RATING = PG-13 COLLATE utf8_bin

13 Columns Present in the Domain Model films.stream().filter(film.rating.equal(rating.pg13)) SELECT `film_id`,`title`,`description`,`release_year`, `language_id`,`original_language_id`,`rental_duration`,`rental_rate`, `length`,`replacement_cost`,`rating`,`special_features`, `last_update` FROM `sakila`.`film` WHERE (`sakila`.`film`.`rating` =? COLLATE utf8_bin)

14 Sorting films.stream().filter(film.rating.equal(rating.pg13)).sorted(film.title.comparator()) SELECT `film_id`,`title`,`description`,`release_year`, `language_id`,`original_language_id`,`rental_duration`,`rental_rate`, `length`,`replacement_cost`,`rating`,`special_features`, `last_update` FROM `sakila`.`film` WHERE (`sakila`.`film`.`rating` =? COLLATE utf8_bin) ORDER BY `sakila`.`film`.`title` IS NULL, `sakila`.`film`.`title` COLLATE utf_bin ASC

15 Do You Recognize This Code? Class.forName("org.postgresql.Driver"); try (Connection conn = DriverManager.getConnection( "jdbc:postgresql://hostname:port/dbname", "username", "password ); PreparedStatementps = conn.preparestatement( SELECT * FROM FILM ResultSetrs= ) { while (rs.hasnext()) { Film film = new Film( rs.gettitle(), ) dosomething(film); } } catch

16 Lazy Evaluation films.stream().filter(film.rating.equal(rating.pg13)).limit(10).foreach(this::dosomething());

17 Parallel Execution films.stream().parallel().filter(film.rating.equal(rating.pg13)).foreach(this::expensiveoperation());

18 Write Your Own Parallel Executor with JDBC

19 Expressing Queries as Streams films.stream().filter(film.rating.equal(rating.pg13)).filter(film.length.greaterthan(75)).count(); SELECT COUNT(*) FROM film WHERE rating ::bytea = PG-13 ::bytea AND length > 75 SELECT COUNT(*) FROM film WHERE rating = PG-13 COLLATE utf8_bin AND length > 75

20 Querying the Database Using Streams SELECT * FROM film Film.RATING.equal(Rating.PG13) Film.LENGTH.greaterThan(75) count()

21 Querying the Database Using Streams SELECT * FROM film WHERE rating = PG-13 COLLATE utf8_bin Film.RATING.equal(Rating.PG13) Film.LENGTH.greaterThan(75) count()

22 Querying the Database Using Streams SELECT * FROM film WHERE rating = PG-13 COLLATE utf8_bin AND length > 75 Film.LENGTH.greaterThan(75) count()

23 Querying the Database Using Streams SELECT COUNT (*) FROM film WHERE rating = PG-13 COLLATE utf8_bin AND length > 75 count()

24 Querying the Database Using Streams SELECT COUNT (*) FROM film WHERE rating = PG-13 COLLATE utf8_bin AND length > 75

25 Is This Really Legit? From the Java 9 Docs for Stream::peek In cases where the stream implementation is able to optimize away the production of some or all the elements (such as with short-circuiting operations like findfirst, or in the example described in count()), the action will not be invoked for those elements.

26 Code Generation Film Java entity interface Generated from the film table Getters and setters from all columns FilmManager Create streams FilmImpl and FilmManagerImpl Default implementation Or write your own

27 Initializing Speedment SakilaApplicationapp = new SakilaApplicationBuilder().withPassword("sakila-password").build(); FilmManagerfilms = app.getorthrow(filmmanager.class);

28 Spring public class AppConfig{ String username; String password; String public SakilaApplication getsakilaapplication() { return new SakilaApplicationBuilder().withUsername(username).withPassword(password).withSchema(schema).build(); }

29 Spring Integration // Individual public FilmManager getfilmmanager(sakilaapplication app) { return app.getorthrow(filmmanager.class); }

30 Spring private FilmManager films;

31 Serving Up a Spring REST Endpoint app.pagesize:50 ) /films/{rating}/{page} ) Stream<Film> pg(@pathvariable String int page) { return films.stream().filter(film.rating.equal(rating)).sorted(film.length.comparator()).skip(page * pagesize).limit(pagesize); }

32 Serving Up REST Endpoint SELECT `film_id`,,`last_update` FROM `sakila`.`film` WHERE (`sakila`.`film`.`rating` =? COLLATE utf8_bin) ORDER BY `sakila`.`film`.`length` ASC LIMIT? OFFSET? values:[pg-13, 50, 500]

33 Speedment Spring Plugin Use the Speedment Spring Plugin to generate a working Rest API Open Source

34 Get Started With Speedment

35 Initializer on speedment.com The Initializer The Initializer allows configuration of a new Speedment project in seconds. To try Enterprise features such as enterprise databases and In-Memory Acceleration, a free 30-day trial is available.

36 Getting Speedment Using Maven <plugin> <groupid>com.speedment</groupid> <artifactid>speedment-maven-plugin</artifactid> <version>3.0.22</version> </plugin>

37 Getting Speedment Using Maven <dependency> <groupid>com.speedment</groupid> <artifactid>runtime</artifactid> <version>3.0.22</version> <type>pom</type> </dependency>

38 Get Started with Speedment

39 Get Started with Speedment Generate Code Write Logic Iterate Run App

40 Speedment API Summary Stream to SQL Lazy Streams Type Safety Parallel Streams

41 Easy Integration - Datasource

42 Deploy Anywhere

43 IDE Integration

44 Web Server Integration

45 Application API 10

46 Speedment Enterprise Same Stream API as Open Source In-JVM-memory acceleration with query latency well below 1 µs 100-1,000 times speed up

47 Learn More How to Use Java Streams to Access Existing Data with Ultra-low Latency Grand Ballroom B, 2:50 PM github.com/speedment/speedment

48 Speedment Style Guide (Just a reminder) Colors Fonts Rubrik: Advent pro #99cfff #cce7ff #6fbbff #45a6fc #ccffff #9bebec #70e1e1 #2bdda0 #9be9ce #33b88a #3a9b79 #ffe591 #fff2c8 #ffda64 #ffcf38 Logos ABCDEFGHIJKLMNPÅQRSTUVWXYZÅÄÖ abcdefghijklmnopqrstuvwxyzåäö!?&@() Brödtext: Source Sans Pro ABCDEFGHIJKLMNPÅQRSTUVWXYZÅÄÖ abcdefghijklmnopqrstuvwxyzåäö!?&@() Kodelement: Source code pro ABCDEFGHIJKLMNPÅQRSTUVWXYZÅÄÖ abcdefghijklmnopqrstuvwxyzåäö!?&@()