2016/11/08

Devoxx 2016 - day 2: notes (2016/11/08)

Array Linked to a List, the full story!

José Paumard


https://stuartmarks.wordpress.com/2015/12/18/some-java-list-benchmarks/
basic operations
  • list.sort
  • list.removeIf()
  • forEach
  • stream()
  • ... random:
  • arraylist
    • will never shrink
    • arraycopy operations
  • http://www.hackersdelight.org/
  • linkedlist:
    • som costly operations
benchmarks: JMH
cpu architecture
Java 9
  • List.of()
  • Set.of()
demo

Exploring Java 9

Venkat Subramaniam

Modularity
  • big rt.jar split in modules ("jmods" subdir)
  • java.base: default dependencies
  • other code also in modules
  • rule: no cycles (cyclic dependencies)
module
  • collection of packages / data
  • name
  • "requires"
  • "exports": only exported stuff can be used
  • convention: put module in dedicated dir
  • module-info.java in a top-level directory
    • module { export ; }
    • "requires java.base;" automatically added
  • public is not "public" anymore -- module-bound
  • examine dependencies
    • jdeps -s (exists since java 8)
    • -Xdiag:resolver
    • java -listmods -- JRE dependencies
  • implied readability: support transitive dependencies
    • "requires public"
  • transition to java 9:
    • jdeps -genmoduleinfo outputdir *.jar
    • put old jars in module path (-mp option)
    • "automatic modules"
    • uses name of jar instead of name of module"
    • classpath: "unnamed module" -- 'quarantined' module (exports all)
  • versions: still ongoing
others
  • jlink: create platformspecific binary executable -- "java"
  • REPL "read evaluate print loop" -- jShell: snippets

The end of polling : why and how to transform a REST API into a Data Streaming API?

Audrey Neveu

"realtime user experience"
  • no refresh buttons
  • solutions
    • polling -- chatty protocol / inefficient
    • alternative
demo with http://streamdata.io and a drone

Open Sesame! Conversations With My Front Door

Maurice Naftalin

raspberry pi for controlling dooropener
  • python
  • asterisk: voip solution
    • complex setup / config
    • freepbx (commercial modules)
    • Asterisk-Java: support Fast AGI -- server on 45373
    • dialplay: voice recognition -- IBM Watson speech recognition service for converting the codes
    • DTMF is more reliable for entering a code future:
    • Natural Language Processing

Notes on Type Theory for absolute beginners

Hanneli Tavante

intro to Type theory
steps:
  • collect all keywords / analyse gramar
  • replace with mathemetics
  • remove duplicates
  • symbolic logic
  • environment (set of classes / variables)
  • predicate logic to analyse your system
  • lambda calculus
  • ...

Post a Comment