Hot.orelse(not)

@hypernation @nickvdh#Devoxx #hotornot

Hot.orElse(not)Nick Vanderhoven

Jeroen Horemans

`


String concatenation

• Compiler optimization with

StringBuilder

• “ To increase the performance

of repeated string

concatenation, a Java compiler

_may_ use the StringBuffer

class or a similar technique to

reduce the number of

intermediate String objects that

are created by evaluation of an

expression. ” - JLS

30 % 70 %

HOT NOT


milli micro nano pico

• nanoTime()

= precision timer

• currentTimeMillis()

= wall clock

• jmh35 % 65 %

HOT NOT


Streams and state

• never modify the same

list an iterator/stream

• sorted() = “stateful

intermediate

operation”

• breaks with parallel()

• mutable shared

variable

59 % 41 %

HOT NOT


Primitive constructors

• @Deprecated(since="9

")

public Integer(int value)

• 5 boolean states

• Boolean.TRUE

• Boolean.FALSE

• new Boolean(true)

• new Boolean(false)

• null

32 % 68 %

HOT NOT


JEP 286: Local-Variable Type Inference

• JEP 286

Feature Candidate

• Author

Brian Goetz

• Reviewed by

Alex Buckley, Mark

Reinhold

72 % 28 %

HOT NOT


Optional.get()

• “I think calling this

method ‘get()’ was our

biggest API mistake in

Java 8.”

- Brian Goetz

• Optional.getWhenPresent()

?33 % 67 %

HOT NOT


Lombok

• Developers are lazy,

but don’t trust anything

they don’t understand

• Beyond JSR 269

(annotation

processors)59 % 41 %

HOT NOT


Exceptions

//no comment

68 % 32 %

HOT NOT


MATCH

1 award-winning author, founder of Agile Developer, Inc., and an instructional

professor at the University of Houston.

Venkat Subramaniam

76 %

95 %

65 %

FRAMEWORKS

FUNCTIONAL

JAVA


Thank you for voting

Nick Vanderhoven

Jeroen Horemans

`

Hot.orelse(not)

Software

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