Transcript Enabling the IBM Blue Stack with Java

Enabling the IBM Blue Stack with Java
October 18th 2010, Bangalore, India
Java Language : New Features in a
nutshell
Lakshmi Narasimhan
© 2010 IBM Corporation
Conference materials may not be reproduced in whole or in
part without the prior written permission of IBM.
Enabling the IBM Blue Stack with Java
Agenda
 Evolution of Java
 Java eco-system
 What’s driving the change
https://espresso.hursley.ibm.com/perl/secure/fetch/j9-60/Other/pxi32hs60/20090206_02/pxi32hs60-20090206_02-hsdk.jar
 New Language Features in JDK7
 Demo
 Q&A
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Bangalore, October 18th 2010
© 2010 IBM Corporation
Enabling the IBM Blue Stack with Java
Disclaimer
Opinions/views expressed
here are my own and
should not be taken as
IBM’s views.
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Bangalore, October 18th 2010
© 2010 IBM Corporation
Enabling the IBM Blue Stack with Java
Evolution of Java - Eras of Java Programming Language
1.
Embedded System (1991-1994)

Originally called Oak

Aimed at electronic devices
2.
Client Side System (1995-1997)

Internet changed it all.

Browsers and Applets gained popularity
3.
Middle Tier System (1997-2007)

Forms core of the 3-Tier Architecture

Powers most of the Middleware systems.
4.
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Language for Languages (2007 onwards):

Powering development of newer Programming Languages

Clojure, Groovy, JRuby, Scala, Rhino, Jython…
Bangalore, October 18th 2010
© 2010 IBM Corporation
Enabling the IBM Blue Stack with Java
Java eco-system
 Relevance of “Java” brand name
– At least 15 known proprietary JVM implementations.
– >30 Free and open source implementations.
 Image of Sun/Oracle in the Community
– More open participation through OpenJDK
– Multiple avenues available for contribution
 Newer/simpler programming paradigms
– Combine the best of interpreted and compiled languages.
– Allow for rapid prototyping and development
 MMP and Cloud scale architectures
– Thousands of “Clustered” JVMs
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© 2010 IBM Corporation
Enabling the IBM Blue Stack with Java
What’s driving the changes
 Faster
– Invoke Dynamic
– Concurrency and Collections update
 Smaller
– Modular Java (Moved to Java8)
 Easier
– Coin
– NIO2
– Method to close a URLClassLoader
 Nicer
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Locale Enhancements
Unicode 6.0
Translucent shaped windows
Swing : Nimbus L&F, JLayer components
XRender pipeline for Java 2D
Bangalore, October 18th 2010
© 2010 IBM Corporation
Enabling the IBM Blue Stack with Java
JDK7 Features - Faster
InvokeDynamic
 Implemented via JSR-292
 Improves compatibility between Java and various dynamic languages, such as Ruby and Python, by
providing better-than-native implementations of these languages on top of the Java Runtime
Environment (JRE).
 Eliminates need for “Glue-code” in the program interpreters.
 Addition of new bytecode – “invokedynamic”
 Read More : http://java.sun.com/developer/technicalArticles/DynTypeLang/
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Bangalore, October 18th 2010
© 2010 IBM Corporation
Enabling the IBM Blue Stack with Java
JDK7 Features - Faster
Concurrency and collections update
 Implemented via JSR 166y
 Light-weight task framework called ForkJoin(FJ)
 Introduces Parallel-Array (PA) concept to Java (simlar to Map-Reduce?)
 Recursive Parallel De-composition of tasks
 Suited for MMP Architectures.
Read More : http://artisans-serverintellect-com.sieioswww6.com/default.asp?W9
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Enabling the IBM Blue Stack with Java
JDK7 Features - Easier
 Project Coin: Small language changes
 New IO2 to define a true filesystem API
 Method to close a URLClassLoader
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Enabling the IBM Blue Stack with Java
JDK7 Features – Easier
Project Coin
 Strings in switch: A simple change that improves regularity in the language
 Improved Type Inference for Generic Instance Creation (diamond)
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© 2010 IBM Corporation
Enabling the IBM Blue Stack with Java
JDK7 Features - Easier
Project Coin
 Simplified varargs method invocation
– Type information from generics gets erased at compile-time.
– Current implementation generates unchecked warning at call time.
– Proposal moves warnings from call site to Method declaration.
 An omnibus proposal for better integral literals
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© 2010 IBM Corporation
Enabling the IBM Blue Stack with Java
JDK7 Features – Easier
Project Coin
 Automatic Resource Management : Automatically close the resources using a new try
clause.
 Applies to Streams, Reader/Writers, Channels, Sockets, SQL operations and even
Graphics.
 When the statement completes, whether normally or abruptly, all of its resources are
closed automatically.
 Obviates the need for manual resource termination which is error prone and ugly.
 Exception chaining masks true failures needing more verbose code (OR) more debugging
time.
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© 2010 IBM Corporation
Enabling the IBM Blue Stack with Java
Project Coin – Automatic Resource Management
 Lets accept it, even good programmers get it wrong!!
 The same code with ARM would look like this:
 Makes the code vastly clear and concise.
 Downside is you lose WYSIWYG (a lot happens under the hood now)
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© 2010 IBM Corporation
Enabling the IBM Blue Stack with Java
JDK7 Features - Easier
New I/O 2
 JSR203
 Need
– Java I/O File API buggy and not fully fail-safe.
– Inconsistent behavior across platforms (eg: rename function)
– Limited support for operating on Files.
 What NIO2 provides:
– “Path” Class Operations
– Support for Directory manipulation
– Recursive File operations – FileVisitor class
– Full support for Symbolic links
– WatchService API
Read more : http://java.sun.com/developer/technicalArticles/javase/nio/
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Bangalore, October 18th 2010
© 2010 IBM Corporation
Enabling the IBM Blue Stack with Java
JDK7 Features - Easier
Method to close a URLClassLoader
 Custom URLClassLoaders are commonly written for loading classes and resources
from file-system directories, jar files or URLs.
 Current implementation does not guarantee a “refresh” of updated
implementations loaded from a particular codebase.
 A new method close() introduced in URLClassLoader which:
– Invalidates the loader (so new classes can be loaded)
– Closes any resource opened by it (jar files)
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© 2010 IBM Corporation
Enabling the IBM Blue Stack with Java
Method to close URLClassLoader
 Code snippet
 Foo.jar now gets updated somehow
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Bangalore, October 18th 2010
© 2010 IBM Corporation
Enabling the IBM Blue Stack with Java
Java7 Features - Nicer
Swing Enhancements
 Swing JLayer component
– Universal decorator for Swing components.
– easily decorate your compound components and catch all Mouse,
Keyboard and FocusEvent for all its subcomponents
– Greatly eliminates verbose AWTEventListeners
 Nimbus L & F :
– Cross platform L&F based on Synth LAF.
– Implemented in Java6 update10.
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Bangalore, October 18th 2010
© 2010 IBM Corporation
Enabling the IBM Blue Stack with Java
Java7 Features - Nicer
XRender pipeline for Java 2D
 a new Java2D graphics pipeline based upon the X11 XRender
extension.
 Aim is to leverage hardware acceleration for most of Java2D’s
functionality.
Locale Enhancements
 Support for IETF BCP 47 and UTR 35 (CLDR/LDML)
Unicode 6.0
 Support for Unicode 6.0 (changed from original goal of 5.1)
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© 2010 IBM Corporation
Enabling the IBM Blue Stack with Java
Want to get your hands dirty?
 Participate in the IBM SDK for Java7 Beta program
 Visit https://www.ibm.com/developerworks/java/jdk/beta/index.html
to enroll.
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Bangalore, October 18th 2010
© 2010 IBM Corporation
Enabling the IBM Blue Stack with Java
Questions?
https://espresso.hursley.ibm.com/perl/secure/fetch/j9-60/Other/pxi32hs60/20090206_02/pxi32hs60-20090206_02-hsdk.jar
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© 2010 IBM Corporation
Enabling the IBM Blue Stack with Java
Useful links
 List of JVM implementations :
http://en.wikipedia.org/wiki/List_of_Java_virtual_machine
s
 Java7 features overview :
http://tech.puredanger.com/java7/
 Project coin updates : http://www.baptistewicht.com/2010/04/java-7-updates-project-coin/
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Enabling the IBM Blue Stack with Java
JDK7 Features overview
Modularity
 A large-scale effort to refactor, or break up, the Java SE platform into smaller, separate,
interdependent modules.
 Implemented via JSR-294
 Java Programming language was not designed with Modularity in mind.
 Many module systems currently exist:
– Most mature implementation is OSGi.
– IntelliJ, Eclipse and Netbeans offer their own Plugin architecture.
 JSR 294 aims at making Modules natively supported by the language.
 Smaller download, start-up performance, smaller footprint.
 Has taken various Avatars : JSR 291 (Dynamic Component Support for Java SE), JSR 277
(Java Module System)
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Enabling the IBM Blue Stack with Java
Modularity
 So what’s changing:
– ClassLoader Architecture
– New java.lang.Module package
– New “module” keyword
– New packaging & distribution formats (one package per module??)
 “module” keyword can be used by compilers to generate “meta” information.
These can then be used for runtime validation for module dependencies,
versioning etc.
 Implemented in OpenJDK via Project Jigsaw
 Aimed at making not just Java Modularized but also application classes.
 Jigsaw modules aimed to be compatible with OSGi systems.
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Bangalore, October 18th 2010
© 2010 IBM Corporation
Enabling the IBM Blue Stack with Java
JDK7 Features overview – Developer Productivity
Type Annotations
 JSR308
 Java6 Annotation syntax useful but limited.
 Type Annotations
allow more expressive programming
 Example : List<@NonNull Object>
 Tools (annotation processors) can then validate the code for
errors.
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