Java Day Tokyo 2013

大きな地図で見る
Java Day Tokyo 2013 was held in Akihabara UDX.

• Keynote
  • Java SE strategy
    • The most improvement : lambda expression
      • Collection becomes more useful
      • Advantage for parallel execution of JVM
    • Other improvements
      • Virtual Extension Methods : Extending existing Interface
      • Project Nashron : Brand-new JavaScript engine
    • Java9 development is going on
    • Java8 : 2014/02 (Delayed from 2013 4Q)
    • Java9 : 2 year after from releasing Java8
  • JavaFX Strategy
    • Plan : Deliverying JavaFX application with JavaFX runtime on Mac AppStore
    • JavaFX is completely OSS-ed : integrated into the openJDK
    • Scene Builder : JavaFX GUI tool
      • Now supports Win and Mac
      • And, supports Linux in 2013 4Q
    • Demo : JavaFX 3D on Microsoft Surface
  • Java Embedded Strategy
    • The most advantege of using Java Embedded : Standarlized
    • Recently, JavaME Embedded 3.3 has been released
  • Java EE Strategy
    • JavaEE 6 has 18 implementations (including Glassfish)
    • JavaEE 7
      • Release plan : 2013/06/13
      • feature closed
      • Batch process
      • JSON
      • WebSocket
      • concurrency
    • Demo : WebSocket
  • Java Community
    • How to join Java community
    • What about Java Community Process
    • Introduction of JJUG
• WebSocket
  • HTTP is half-duplex
  • HTTP is verbose
  • Last technologies for server push (e.g. polling, comet) are complex and inefficient.
  • WebSocket
    • bi-directional full-duplex messaging
    • IETF-defined RFC6455
    • W3C-defined JavaScript API
    • No headers, cookies authentication
  • Procedure
    
    1. handshake as HTTP
    2. Upgrade from HTTP to WebSocket
    3. handshake as WebSocket
  • Protocol is ws://
  • HTTP is client-server / WebSocket is peer-peer
  • To survey supporting Browser : caniuse.com/websockets
  • IE starts supporting WebSocket since IE10
  • JSR356
    
    • Standard Java API for creating WebSocket Application
    • A part of JavaEE 7
    • java.net/projects/tyrus
  • WebSocket and Glassfish 4
    
    • details of JSR356 annotations
    • details of TextDecoder / TextEncoder
    • details of Dependency Injection
  • Servlet API 3.1 adds new API HttpServletRequest.upgrade
  • How about secutiry
    • Do secure-releated procedures and authentications on HTTP, before handshaking WebSocket
    • WebSocket with SSL (wss://)
• Lambda Expression
  • Multicore processor is current evolution of CPU
  • JavaSE should adapt multicore and parallel
  • external iteration is serial, and hard to be parallel
  • internal iteration is NOT serial, and easy to be parallel
  • a good way of internal iteration : iambda expression
  • Lambda in JavaSE 8
    • Not only internal iteration, target typing
    • It is Not closure
    • this indicates enclosing class, does not indicate inner lambda
    • Parameters of lmabda can do type inference
    • New accessor notation :: : (single method call)
  • When updating collections for lambda in JavaSE class library
    
    • Collection is defined as Interface
    • changing interface means changing all of concrete classes
    • But, JavaSE class library is required backward compatibility
    • So that JavaSE 8 also adapts also Virtual Extension Method
  • Virtual Extension Method
    • A new syntax to extend existing interface
    • Defining both new API and default behavior for it
  • JavaSE 8's lambda is optimized by using invokedynamic when compiled : so that javac uses invokedynamic since JavaSE 8
• Batch Applications
  • JSR352 : IBM leads standarlization for Java Batch Processes
  • A part of JavaEE 7
  • But it can us stand-alone on Java SE : java.net/projects/jbatch
  • Details of JSR352 architecture
    • Job, Step
    • ItemReader, ItemProcessor, ItemWriter
    • Partitioning : Mapper, Reducer, Collector, Analyzer
  • Job Supecification Language(JSL) : XML for Java Batch DSL
    • How to handle/not-handle exceptions : skippable-exception, retryable-exception, no-rollback-exception
    • Flow : a serial set of Steps
    • Split : a parallel set of Flows
  • Demo
• invokedynamic and Project Nashorn
  • invokedynamic : one of bytecode instruction since Java SE 7
  • In Java SE 7 : used for dynamic languages running on JVM
  • In Java SE 8 : used also for optimizing lambda expression when compiled
  • Details of invokedynamic
  • dynamic languages on JVM : JRuby, Jython, Groovy and so forth
  • difficulties of creating dynamic language
    • Type is not determined at some time
    • members of class and object are changable
    • Ablilty to re-define existing members
  • Project Nashorn
    • A JavaScript engine for JVM using invokedynamic
    • JavaSE6, JavaSE7 bundles Rhino
      • invokedynamic is not used
      • It's slow
    • It also roles as reference implementation for using invokedynamic
    • Target : running node.js
    • ECMAScript based
    • Faster
    • Size is well small for using in Java Embedded

And, in this day, Oralce Japan has announced that they release Java Documentation Japanese Edition.
Java Platform Standard Edition 7 Document (Japanese)
Java Platform Standard Edition 7 API Document (Japanese)