What's new in Java 8

What’s New in Java 8?
John Clingan
Oracle
Product Manager – Java EE, GlassFish,
EclipseLink, Avatar

Copyright © 2014, Oracle and/or its affiliates. All rights reserved.2
The following is intended to outline our general product
direction. It is intended for information purposes only, and may
not be incorporated into any contract. It is not a commitment to
deliver any material, code, or functionality, and should not be
relied upon in making purchasing decisions. The development,
release, and timing of any features or functionality described
for Oracle s products remains at the sole discretion of Oracle.

Copyright © 2014, Oracle and/or its affiliates. All rights reserved.3 3
Lambda (JSR 335)
Date/Time API (JSR 310)
Type Annotations (JSR 308)
Compact Profiles
Lambda-Form Representation for Method Handles
Remove the Permanent Generation
Improve Contended Locking
Generalized Target-Type Inference
DocTree API
Parallel Array SortingBulk Data Operations
Unicode 6.2
Base64
Prepare for Modularization
Parameter Names
TLS Server Name Indication
Configurable Secure-Random Number Generation
Java SE 8
Nashorn
Enhanced Verification Errors
Fence Intrinsics
Repeating Annotations
HTTP URL Permissions
Limited doPrivileged
http://openjdk.java.net/projects/jdk8/features

Java SE 8:
Enhancing The Core Java
Platform

Java SE 8
!  Biggest change in the Java language since Java SE 5
!  Significant enhancements to the class libraries
!  The main goal of these changes are …
–  Better developer productivity
–  More reliable code
–  Better utilization of multi-core / multi-processor systems
!  Code is no longer inherently serial or parallel

Lambda Expressions
!  Almost all machines now are multi-core, multi-processor, or both
!  We need to make it simpler to write multi-threaded Java code
–  Java has always had the concept of threads
–  Even using the concurrency utilities and fork-join framework this is hard
!  Let’s add better library code
–  This is good, but sometimes we need to change the language too
!  The answer: Lambda expressions and the streams API
!  Backwards compatible with existing APIs like Collections.
Why Do We Need Them?

Lambda & Streams Demos

Stream Sources
!  From collections and arrays
–  Collection.stream()
–  Collection.parallelStream()
–  Arrays.stream(T array) or Stream.of()
!  Static factories
–  IntStream.range()
–  Files.walk()
!  Roll your own
–  java.util.Spliterator()
Many Ways To Create

Stream Sources
!  Access to stream elements
!  Decomposition (for parallel operations)
–  Fork-join framework
!  Stream characteristics
–  ORDERED
–  DISTINCT
–  SORTED
–  SIZED
–  SUBSIZED
–  NONNULL
–  IMMUTABLE
–  CONCURRENT
Manage Three Aspects

Optional<T>
!  Used in new Java 8 APIs to replace null
!  Indicates that reference may, or may not have a value
!  Makes developer responsible for checking
Reducing NullPointerException Occurences
Optional<GPSData> maybeGPS = Optional.of(gpsData);
maybeGPS = Optional.ofNullable(gpsData);
maybeGPS.ifPresent(GPSData::printPosition);
GPSData gps = maybeGPS.orElse(new GPSData());
maybeGPS.filter(g -> g.lastRead() < 2).ifPresent(GPSData.display());

java.util.function Package
!  Predicate<T>
–  Determine if the input of type T matches some criteria
!  Consumer<T>
–  Accept a single input argumentof type T, and return no result
!  Function<T, R>
–  Apply a function to the input type T, generating a result of type R
!  Plus several more

Annotations On Java Types
!  Annotations can currently only be used on type declarations
–  Classes, methods, variable definitions
!  Extension for places where types are used
–  e.g. parameters
!  Permits error detection by pluggable type checkers
–  e.g. null pointer errors, race conditions, etc
public void process(@notnull List data) {…}

Concurrency Updates
!  Scalable update variables
–  DoubleAccumulator, DoubleAdder, etc
–  Multiple variables avoid update contention
–  Good for frequent updates, infrequent reads
!  ConcurrentHashMap updates
–  Improved scanning support, key computation
!  ForkJoinPool improvements
–  Completion based design for IO bound applications
–  Thread that is blocked hands work to thread that is running

Parallel Array Sorting
!  Additional utility methods in java.util.Arrays
–  parallelSort (multiple signatures for different primitives)
!  Anticipated minimum improvement of 30% over sequential sort
–  For dual core system with appropriate sized data set
!  Built on top of the fork-join framework
–  Uses Doug Lea’s ParallelArray implementation
–  Requires working space the same size as the array being sorted

Date And Time APIs
!  A new date, time, and calendar API for the Java SE platform
!  Supports standard time concepts
–  Partial, duration, period, intervals
–  date, time, instant, and time-zone
!  Provides a limited set of calendar systems and be extensible to others
!  Uses relevant standards, including ISO-8601, CLDR, and BCP47
!  Based on an explicit time-scale with a connection to UTC

Base64 Encoding and Decoding
!  Currently developers are forced to use non-public APIs
–  sun.misc.BASE64Encoder
–  sun.misc.BASE64Decoder
!  Java SE 8 now has a standard way
–  java.util.Base64.Encoder
–  java.util.Base64.Decoder
–  encode, encodeToString, decode, wrap methods

Nashorn JavaScript Engine
!  Lightweight, high-performance JavaScript engine
–  Integrated into JRE
!  Use existing javax.script API
!  ECMAScript-262 Edition 5.1 language specification compliance
!  New command-line tool, jjs to run JavaScript
!  Internationalised error messages and documentation

Native Memory Usage
!  No more tuning PermGen
–  PermGen – Artificial memory limitation
–  Metaspace – Regular native allocation
!  Limited only by process address space
!  Can force a limit: -XX:MaxMetaspaceSize=<size>
–  Part of the HotSpot, JRockit convergence
!  Class data sharing across processes – Experimental feature
–  Available on all platforms, -Xshare:[off|on|auto]
–  Reduce footprint and startup sharing JDK classes between processes
No more “java.lang.OutOfMemoryError: PermGen space”

Multistep Optimization
!  Interpreter " Client Compiler " Server Compiler
–  Fast initial compilation
–  Keep peak performance
–  Enabled by default
!  Improve time to performance
–  Startup of large applications
–  Performance for short running applications
Tiered Compilation

Java EE Application Deployment
Tiered Compilation

JSR 292 - InvokeDynamic
!  Complete rewrite of the VM support for JSR 292
–  Improved stability, maintainability and performance
!  Lambda
–  Avoid repeated calculations during capture
–  No allocation for non-capturing Lambdas
–  On par or faster than inner classes
!  JavaScript Engine – Nashorn
–  Incremental inlining of MethodHandle invocations
Major Updates

JavaScript Engine - Nashorn
JSR 292 - InvokeDynamic
JDK 8 updates double performance of a couple of these

Java Mission Control

JavaFX 8
New Stylesheet
24
Caspian vs Modena

JavaFX 8
!  Customisable
–  Configurable key combinations to exit full screen mode
–  Ability to prevent user exiting full screen mode
Improvements To Full Screen Mode
// Set the key combination that the user can use to exit
stage.setFullScreenExitKeyCombination(KeyCombination.NO_MATCH);
// Setup the click handler so we can escape from full screen
Rectangle r = new Rectangle(0, 0, 250, 250);
r.setOnMouseClicked(e -> stage.setFullScreen(false));
// Set full screen again
stage.setFullScreen(true);

JavaFX 8
!  New API for printing
–  Currently only supported on desktop
!  Any node can be printed
Printing Support
PrinterJob job = PrinterJob.createPrinterJob(printer);
job.getJobSettings().setPageLayout(pageLayout);
job.getJobSettings().setPrintQuality(PrintQuality.HIGH);
job.getJobSettings().setPaperSource(PaperSource.MANUAL);
job.getJobSettings().setCollation(Collation.COLLATED);
if (job.printPage(someRichText))
job.endJob();

JavaFX 8
!  DatePicker
!  TreeTableView
New Controls

JavaFX 8
!  Gestures
–  Swipe
–  Scroll
–  Rotate
–  Zoom
!  Touch events and touch points
Touch Support

JavaFX 8
!  Predefined shapes
–  Box
–  Cylinder
–  Sphere
!  User-defined shapes
–  TriangleMesh, MeshView
!  PhongMaterial
!  Lighting
!  Cameras
3D Support

Compact Profiles
Approximate static footprint goals
Compact1 Profile
Compact2 Profile
Compact3 Profile
Full JRE 54Mb
30Mb
16Mb
11Mb
[Migration path for CDC,
logging and SSL]
[Adds XML, JDBC, RMI]
[Adds mgmt, naming, more
security, compiler support]

Java SE Public Updates Schedule
GA Date
Notification of
End of Public Updates
End of Public Updates
Java SE 1.4.2 Feb 2002 Dec 2006 Oct 2008
Java SE 5 May 2004 Apr 2008 Oct 2009
Java SE 6 Dec 2006 Feb 2011 Feb 2013
Java SE 7 July 2011 Mar 2014 April 2015
Java SE 8 Mar 2014 Mar 2016* TBD
For details see, http://www.oracle.com/technetwork/java/eol-135779.html
* Or later. Exact date TBD.

Books
!  “Java SE 8 for the Really Impatient” (Horstmann)
!  “Functional Programming in Java: Harnessing the Power of Java 8
Lambda Expressions” (Subramaniam)
!  “Mastering Lambdas: Java Programming in a Multicore World” (Naftalin)
!  “Java 8 in Action: Lambdas, Streams, and functional-style
programming” (Urma, Fusco, Mycroft)
!  “Java 8 Lambdas: Pragmatic Functional Programming” (Warburton)
!  “Java in a Nutshell” (Evans, Flanagan)

Where Next?

Java 9 And Beyond
!  Modularisation of the Java platform
–  Project Jigsaw
!  Foreign function interface
–  Like JNA
!  Enhanced volatiles
Java Never Stops

Java SE Lifetime Support Policy
GA Date Premier Support Extended Support
Java SE 1.4.2 Feb 2002 Feb 2010 Feb 2013
Java SE 5 May 2004 May 2011 May 2015
Java SE 6 Dec 2006 Dec 2015 Jun 2018
Java SE 7 July 2011 July 2019 July 2022
Java SE 8 Mar 2014 Mar 2022 Mar 2025
For details see, http://www.oracle.com/support/library/brochure/lifetime-support-middleware.pdf

Java SE Platform enhanced with enterprise-grade features for
monitoring, manageability, and analytics.
# 24x7 support, offered in 27 local languages
# Security updates on older and current releases
# Only source for Java SE 6 updates after Feb 2013
# Monitor, manage, and profile Java desktop applications
# Enterprise JRE features i.e., Java SE usage tracking
Java SE Commercial Products
Java SE Suite
Java SE Platform hardened for mission
critical applications having extreme and
predictable computing needs.
# Soft real-time deterministic garbage collector for
mission critical applications
# Memory leak server for dynamic memory leak
detection on mission critical production systems
Java SE Support
Oracle Premier Support for Java SE.
# 24x7 support, offered in 27 local languages
# Security updates on older and current releases
# Only source for Java SE 6 updates after Feb 2013
# Enterprise JRE features i.e., update control
Java SE Advanced Desktop and Java SE Advanced

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