Ao longo da história muito se falou sobre o Java ME, essa plataforma ficou muito famosa, principalmente na era do “celular tijolão”. Após o grande boom dos smartphones surgiu a grande dúvida: Para onde foi parar o JavaME? Ele morreu? O objetivo dessa palestra é falar sobre estratégias com o Java ME e das primeiras especificações que estão sendo trabalhadas no dos embarcados e internet das coisas.

1. Java API ME next
Otávio Santana
@otaviojava
otaviojava@java.net
otaviojava@apache.org

2. OpenJDK
• Java 7
• Java 8
• Java 9

3. OpenJDK
hg clone http://hg.openjdk.java.net/jdk9/jdk9 jdk_1_9
sh ./get_source.sh
./configure
make install

4. Launched the Java 8
● Lambda
● Metaspace
● Stream

5. Java 9
● Build: 85
● https://jdk9.java.net/download/
● Java 8 faster

6. Java 9
Reflections wrappers Regex Security Core
0
50
100
150
200
250
Java 8 - Process
Java 9 -Process
Java 8 - Memory
Java 9 -Memory

7. Improvements in GC
● Remove GC combinations deprecated
●
Strings Deduplication
● Segmented Code Cache
● Shenandoah

8. Strings duplication
● 25% of Heap are Strings
● 13.5% String duplicates
75
25
Heap
Another objects String
85
15
String inside Heap
String Strings duplicates

9. Segmented
Code Cache
● JVM internal (non-method) code
● Profiled-code
● Non-profiled code

10. JigSaw
● Scalable
● Performance
● Small computing devices

11. Java ME
● Java ME 8.2
● 2015
● Language Improvements
Java ME 8Java ME 8
Java SE 8
Language

12. News Features
● Collections
● Generics
● AutoBoxing
● Enum
● Try with
resources
● LoggingJava ME 8
Java SE 8
API

13. But still hasn't
● BigDecimal
● Reflection
● DI
● Lambda
● Streams
Java ME 8
Java SE 8
API

14. Zero-Assembler Project
● Portability
● C++
● Processor
Architecture
Java SE 8

15. Shark
● LLVM-based JIT
● Panama
● JEP 191
Java SE 8

16. AArch64 Port Project
● 64-bit mode of
ARMv8
● Panama
● JEP 191
Java SE 8

17. JVM on Modules
● Modules
● Profiles
Java SE 8

18. Mobile OpenJDK
● Java 9
● Java 8's
compact2
Java SE 8

19. Mobile OpenJDK
● iOS x64 and arm64
● Android x86 and
arm32
● Windows 10 x64
Surface Pro
● JavaLauncher helper
interface
Java SE 8

20. Java
● Java ME
● Java Embedded
● OpenJDK Mobile
● Java SE
Java SE 8

21. Measurement API
● Work with Measure
● Standardize measure unit
● Format
● Operations (convert, add, subtract)

22. Measurement API
5,898 ??????
A Measurement
A Unit
London
São Paulo

23. Measurement API
int distance = 5898; //in miles
float speed = airplane.getSpeed();
//in km/h
System.out.println(“ETA: “ +
(distance/speed) + “ hours”);
int distance = 5898; //in miles
float speed = airplane.getSpeed();
//in km/h
System.out.println(“ETA: “ +
(distance/speed) + “ hours”);
5,898 ??????
A Measurement
A Unit

24. Measurement API
LEARNING FROM
THE PAST…

25. Sea Level
Some real-life mishaps...
NASA “Star Wars” Initiative, 1983

26. Some real-life mishaps...
NASA Mars Orbiter, 1999
“Preliminary findings indicate that one team used
US/English units (e.g. inches, feet and pounds)
while the other used metric units for a key
spacecraft operation.”

27. Conversion problems
These are examples of confusion on the units in application.
But there is also ambiguity on the unit itself:
10 Gallons … Gallon Dry / Gallon Liquid - Gallon US / Gallon UK
28 Days … Day Sidereal / Day Calendar
38 Degrees … Degree Celsius / Degree Fahrenheit / Degree Angle
And the wrong conversion factors:
static final double PIXEL_TO_INCH = 1 / 72;
double pixels = inches * PIXEL_TO_INCH;

28. Measurement API
QuantityFactory<Mass> massFactory =
QuantityFactoryProvider.getQuantityFactory(Mass.class);
Quantity<Mass> tenKilogram = massFactory.create(10,
SI.KILOGRAM);

29. Measurement API
QuantityFactory<Time> timeFactory =
QuantityFactory.getInstance(Time.class);
Quantity<Time> m1 = timeFactory.create(40, MINUTE);
Quantity<Time> m2 = timeFactory.create(20, MINUTE);
Quantity<Time> h1 = m1.add(m2).to(HOUR); //1 hour

30. Measurement API
QuantityFactory<Time> timeFactory =
QuantityFactory.getInstance(Time.class);
Quantity<Time> m1 = timeFactory.create(1, DAY);
Quantity<Time> m2 = timeFactory.create(12, HOUR);
Quantity<Time> result = m1.add(m2); //1.5 day

31. Measurement API
Quantity<Time> minutes = Quantities.getQuantity(15,
SI.MINUTE);
Quantity<Time> hours = Quantities.getQuantity(18, SI.HOUR);
Quantity<Time> day = Quantities.getQuantity(1, SI.DAY);
Quantity<Time> seconds = Quantities.getQuantity(100,
SI.SECOND);
List<Quantity<Time>> times = new ArrayList<>();
times.addAll(Arrays.asList(minutes, hours, day, seconds));

32. Measurement API
List<Quantity<Time>> sortNaturalList = times.stream()
.sorted(QuantityFunctions.sortNatural())
.collect(Collectors.toList());
● seconds - 100 seconds
● minutes - 15 minutes
● hours - 18 hours
● day - 1 day

33. Measurement API
List<Quantity<Time>> sortNaturalList = times.stream()
.sorted(QuantityFunctions.sortNaturalDesc())
.collect(Collectors.toList());
● day - 1 day
● hours - 18 hours
● minutes - 15 minutes
● seconds - 100 seconds

34. Measurement API
times.add(Quantities.getQuantity(24, SI.HOUR));
Comparator<Quantity<Time>> sortNatural = QuantityFunctions.sortNatural();
Comparator<Quantity<Time>> sortSymbol = QuantityFunctions.sortSymbol();
List<Quantity<Time>> sortNaturaAndSymbolList = times.stream()
.sorted(sortNatural.thenComparing(sortSymbol)) .collect(Collectors.toList());
● seconds - 100 seconds
● minutes - 15 minutes
● hours - 18 hours
● day - 1 day
● dayInHour – 24 hours

35. Measurement API
List<Quantity<Time>> greaterThanOneDay = times
.stream()
.filter(QuantityFunctions.isGreaterThan(oneDay)).collect(Collect
ors.toList());
List<Quantity<Time>> greaterThanOneDay = times
.stream().filter(QuantityFunctions.isBetween(oneHour,
oneDay)).collect(Collectors.toList());

36. Measurement API
Mixing Filters
QuantityFunctions.isGreaterThan(oneDay).and(QuantityFunctio
ns.fiterByUnit(SI.HOUR)));
QuantityFunctions.isGreaterThan(oneDay).or(QuantityFunction
s.fiterByExcludingUnit(SI.DAY)));

37. Measurement API
QuantitySummaryStatistics<Time> summary =
times.stream().collect(QuantityFunctions.summarizingMeasure(
SI.HOUR)); //result in hours
summary.getCount();
summary.getAverage();
summary.getMax();
summary.getMin();
summary.getSum();

38. Measurement API
QuantitySummaryStatistics<Time> summaryDay =
summary.to(SI.DAY);
summary.getMin(SI.MINUTE);
summary.getMax(SI.MINUTE);
summary.getSum(SI.MINUTE);
summary.getAverage(SI.MINUTE);

39. Measurement API
Quantity<Time> t1 = timeFactory.create(1, DAY);
Quantity<Mass> m1 = timeFactory.create(12, KILOGRAM);
Quantity<Length> l1 = timeFactory.create(12, KILOGRAM);
t1.add(m1); //error
Quantity<Speed> s1 = l1.divide(t1).asType(Speed.class);

40. Measurement API
● Acceleration
● Length
● Angle
● Area
● Mass
● Power
● Energy
● Speed
● Force
● Temperature
● Time
● Information
● Volume
And more! 52 quantities

41. Measurement API
Package Description
javax.measure Core API interfaces (e.g. Dimension,
Quantity, Unit)
javax.measure.format [optional] Interfaces for quantity/unit formatting and
parsing
javax.measure.quantity [optional] Interfaces for quantity types (e.g. Mass,
Length)
javax.measure.spi [optional] Service Provider Interface (implementation
discovery)

42. Measurement API
Quantity<Length> distance = Quantities.getQuantity(5898,
US.MILE);
Quantity<Speed> airplaneSpeed = getAirplaneSpeed();
Quantity<Time> eta =
(Quantity<Time>)distance.divide(airplaneSpeed);
System.out.println(“ETA: “+ eta.to(SI.HOUR));
ETA: 10.54655… h
Quantity<Length> distance = Quantities.getQuantity(5898,
US.MILE);
Quantity<Speed> airplaneSpeed = getAirplaneSpeed();
Quantity<Time> eta =
(Quantity<Time>)distance.divide(airplaneSpeed);
System.out.println(“ETA: “+ eta.to(SI.HOUR));
ETA: 10.54655… h

43. JSR 377
● dependency injection via JSR330
● common application structure
● application life-cycle
●
localized resources
● resource injection
● localized configuration
● decouple state from UI (binding)
● persistence session state (preferences)
●
action management
● component life-cycle
● light-weight event bus
● honor threading concerns (specific to UI toolkit)
● application extensibility via plugins (implies modularity)

44. Thank you
Otávio Santana
@otaviojava