This document provides an overview and agenda for a presentation on Java 8 features and the Jinq library. It discusses Java 8 language features like lambda expressions and default methods. It then describes Jinq, an open-source library that allows functional-style database queries in Java by translating Java code into SQL. The document outlines how Jinq works, its configuration, supported query operations like filtering, sorting and joins, and limitations. It also briefly mentions alternative libraries like JOOQ.

1. Java 8 in action.
Jinq
Sergey Morenets, morenets@mail.ru
March, 12 2015

2. About author
• Works in IT since 2000
• 11 year of Java SE/EE experience
• Regular speaker on Java User Group conferences
• Java evangelist

3. Agenda
• Java 8 overview
• Libraries support
• Jinq
• Q&A

4. Java 8 overview

5. Java 8 overview
• Lambda expressions
• Streams API
• Java time
• Default & static methods
• Method references
• Repeating & type annotations
• Hashorn
• Metaspace

6. Native support
• Lambda expressions
• Default methods
• Method references
• Nashorn
• Metaspace

7. Type annotations
• @Nullable
• @NonNull
• @ReadOnly

8. Repeatable annotations
• Spring Framework

9. Java time
• Joda replacement
• Supported in Spring 4
• Ignored by Hibernate, partially supported by JPA

10. Hibernate

11. JPA

12. JPA

13. Streams API

14. Streams API

15. File storage

16. Data access

17. Data access
• JDBC
• Spring JDBC
• ORM (Hibernate)
• JPA
• Functional programming

18. Recently
• SQL
• HQL/JPQL
• Hibernate/JPA criteria
• Custom API

19. Jinq
• Initially developed by Dr. Ming-Yee
• Open-source project
• Functional database queries in Java and Scala
• Inspired by LINQ
• Required JPA & Java 8

20. Jinq flow
• Translated Java code and Run it as database query
statements
• Run as ordinary Java code

21. Configuration
• Map entities
• JPA provider
• JPA configuration

22. Configuration

23. Configuration

24. Count
select count(city.id) from City city

25. Filtering

26. Jinq
select city.id, city.name, city.population from City city
limit ?

27. Where
select count(city.id) from City city where
city.population>100

28. Variables
select count(city.id) from City city where
city.population > ?

29. Select
select city.name from City city limit ?

30. Comparison
select count(city.id) from City city where
city.name='Odessa'

31. Comparison
select count(city.id) from City city where city.name is
not null

32. Concatenation
select concat('City:', city.name) from City city limit ?

33. Concatenation

34. Aggregate
select max(city.population) from City city

35. Methods

36. Sorting
select city.id, city.name, city.population as from City
city order by city.population ASC, city.name ASC limit
?

37. Country

38. Associations
select count(city.id) from City city cross join Country
country where city.countryId=country.id and
country.name='Ukraine'

39. Pairs
select city.id, country.id, city.countryId, city.name,
city.population, country.name from City city inner join
Country country on city.countryId=country.id limit ?

40. Join
• join()
• joinList()
• selectAll()

41. Grouping
• select city.countryId, sum(city.population),
count(city.id), country.id, country.name from City
city inner join Country country on city.countryId=
country.id group by city.countryId limit ?

42. Limitations
• Your code cannot contain any loops
• Your code can call other methods but only those
from a restricted list with known side-effects
• Your code can read and modify local variables
(since these changes will be discarded once the
function exits)
• Your code can read but not modify non-local
variables
• Your code cannot contain casting between
different data types

43. Data types
Java type Supported operations
String equals()
BigDecimal, BigInteger, Integer,
int, Double, double, Long, long
==, <, <=, >, >=, !=, +, -, *, /
Boolean, boolean !, &&, ||, ==
java.util.Date, java.sql.Date,
java.sql.Time,
java.sql.Timestamp,
java.util.Calendar
equals(), before(), after()
enums ==, !=
entities ==, !=
java.util.Collection contains(), JPQL.isIn()

44. Functions
Java JPQL alternative
Math.abs() / BigDecimal.abs() /
BigInteger.abs()
ABS()
Math.sqrt() SQRT()
% MOD()
String.toUpperCase() /
String.toLowerCase()
UPPER() / LOWER()
String.trim() TRIM()
String.length() LENGTH()
String.indexOf() LOCATE()

45. Pro
• Brings up functional style
• Database & provider independent
• SQL-92 - compatible

46. Cons
• Requires JPA
• Limited to JPA functionality
• No stored procedures
• Lacks NoSQL support
• Hard to debug

47. To be continued?
• XML
• JSON
• JDBC

48. Jooq
• Java object oriented querying
• Lightweight alternative
• JDBC wrapper
• SQL building, code generation & SQL execution
• Jinq provides basic support for Jooq
• Open-source & paid version

49. References

50. Q&A
Sergey Morenets, morenets@mail.ru