j2se5.0

java.sun.com/javaone/sf

| 2004 JavaOneSM Conference | Session TS-1952 1

Fast Track to Java™ 2 Platform, Standard Edition (J2SE™) 5.0 Technology

Calvin Austin J2SE 5.0 Specification LeadSun Microsystems, Inc.


Learn the key features of J2SE™ 5.0 technology in one hour!

Goal of This Presentation


Your Next Java™ Platform

“I think I’m becoming a geek, because for the first time in five years I’m actually excited about some technology.”

Beta1 Feedback


Agenda

� Introduction to “Tiger”� Main Theme Features� Miscellaneous Features� Demo� Q&A


“Tiger” J2SE 5.0 Technology

� Developed using the Java Community ProcessSM services

� 15 component JSRs for major new features� Over 160 Experts Worldwide� Over 100 Features� Lots of bug fixing and performance work


J2SE 5.0 Technology Timeline

FCSQ3 04

Beta12/4

Beta25/27

RC

2004 2005


“Tiger” Component JSRs

� 003 JMX™ API� 013 Decimal Arithmetic� 014 Generic Types� 028 SASL� 114 JDBC™ Rowsets� 133 New Memory Model� 160 JMX Remote API� 163 Profiling API

� 166 Concurrency Utilities� 174 Monitoring and

Management� 175 Metadata� 200 Pack transfer format� 201 Language updates� 204 Unicode surrogates� 206 JAXP 1.3


“Tiger” Themes

� Quality─ Compatibility, compatibility, compatibility!

� Performance and scalability� Ease of development� Monitoring and manageability� Desktop client


“Tiger” Themes


� Performance and scalability� Ease of development� Monitoring and manageability� Desktop client


� Far tighter controls on quality� Lots and lots of bug fixing� Compatibility is key to successful migration� Reliability and stability are critical

Quality, Stability, Compatibility


“Tiger” Themes


� Performance and scalability� Ease of development� Monitoring and manageability� Desktop Client


Focus on Performance

� Even more support for big heaps─ Improved concurrent/parallel collectors

� Yet more Java HotSpot™ VM tuning─ Chipset optimizations─ AMD64 native compiler─ Hyper-threading/CMT


More Performance!

� Faster startup time─ Especially important for desktop applications

� Class Data Sharing, generated at install time� java -Xshare:off to disablejava -Xshare:dump to re-generate


Even More Performance!

� Performance Ergonomics─ Less reliance on command line flags─ More support for adaptive self-tuning

� Performance tools─ Jstat and jvmstat

jstat -class 6047Loaded Bytes Unloaded Bytes Time173 135.6 0 0.0 0.81l


Performance Ergonomics

� Server class performance for Server class machines out of the box─ 2 CPU and 2 GB RAM─ Parallel Garbage Collector─ Server Java Hotspot VM compiler─ Max Heap ¼ Max Memory or 1GB─ Initial Heap 1/64 Max Memory or Max Heap


Internal Tests

Startup minimal awt applet minimal Swing app0

10

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60

70

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90

100

Reduction in Windows Startup Time

1.4.25.0build47


“Tiger” Themes




Ease of Development Changes

� MetaData� Generics� Autoboxing� Enhanced for loops� Enumerated Types, Static Import� Covariant Return Types� Formatted Output/Input� Varargs� Concurrency Utilities


Compiler Options

� Default javac compiler wants 1.5 compatible source

� Only use -source 1.4 for backward source compatibility

� Only use -source 1.4 -target 1.4 for corner cases


Metadata

� Key new Java programming language idea� Allows decoration of

packages/classes/methods/fields for simpler declarative programming

� Can be retained in class file and also be visible at runtime

� Designed for use by tools, apt tool available in beta2


Metadata

� Declared using @interface

� @Retention(RUNTIME) @interface debug {

boolean devbuild() default false;

int counter();}

� Developer specifies metadata using @tag

� public @debug mymethod;


APT Tool

� Front end to Java language Compiler� Parses metadata with AnnotationProcessorFactory

� AnnotationProcessorFactory selects an AnnotationProcessor

� AnnotationProcessor has a process()method to handle metadata tags

� process() method has access to a Filerclass to create source, class or text files

� PrintWriter pw = env.getFiler().createSourceFile("Ex1");


Java Web Services Tutorial Example: JAX-RPC Server

Before

public interface HelloIF extends Remote {public String sayHello(String s) throws RemoteException;

}

public class HelloImpl implements HelloIF {public String sayHello(String s) {

return “Hello “+s;}

}

Afterpublic class HelloImpl {

public @remote String HelloImpl(String s) {return "Hello “+s;

}}


Generics

� What happens today?─ When creating shared algorithms that work on

different types, designers have to use the general Object type, e.g., Collections

� What is the problem with that?─ Developers have to explicitly cast down to

retrieve the object they need. This negates type safety checking


Generics Solution

� The solution� Allow the developer to provide a type

parameter at declaration time inside <..>, e.g., <Integer>

� The compiler now can check for type safety� Collections have been updated to use

Generics


Generics Example

Before

ArrayList list = new ArrayList();list.add(0, new Integer(42));int total = ((Integer)list.get(0)).intValue();

After

ArrayList<Integer> list = new ArrayList<Integer>();list.add(0, new Integer(42));int total = list.get(0).intValue();


Writing Generics APIs

� Warning: generifying old APIs needs careful thought

� Look at Collections API source for examples� For portability, old Collections API is

compatible with Generic Collections API


Pre-Generic API

public class MoneyBox {private Vector pot =new Vector();

public void addCoin(Object o) {pot.add(o);

}

public Object getMoney() {return pot.firstElement();

}

public static void main(String[] args) {MoneyBox m= new MoneyBox();m.addCoin("iou");m.addCoin(new Integer(3));

System.out.println(((Integer)m.getMoney()).intValue()); }

}


Pre-Generic Result

$ javac MoneyBox.java

$ java MoneyBox

Exception in thread "main" java.lang.ClassCastException: java.lang.String

at MoneyBox.main(MoneyBox.java:18)


Generified Version

public class MoneyBox<M> {Vector<M> pot =new Vector<M>();

public void addCoin(M o) {pot.add(o);

}

public M getMoney() {return pot.firstElement();

}

public static void main(String[] args) {MoneyBox<Integer> m= new

MoneyBox<Integer>();m.addCoin("iou");m.addCoin(new Integer(3));System.out.println(m.getMoney());

}}


Generic Result

$ javac MoneyBox.java

MoneyBox.java:15: addCoin(java.lang.Integer) in MoneyBox<java.lang.Integer> cannot be applied to (java.lang.String)

m.addCoin("iou");

^

1 error


Autoboxing of Primitive Types

� Conversion to and from primitive types to their Object equivalent

Before

list.add(0, new Integer(42)); int total = (list.get(0)).intValue();

After

list.add(0,42);int total = list.get(0);


Enhanced for Loop

� Simplified iterating over collections

BeforeArrayList<Integer> list = new

ArrayList<Integer>();for (Iterator i = list.iterator();i.hasNext();{

Integer value=(Integer)i.next();}

After

ArrayList<Integer> list = new ArrayList<Integer>(); for (Integer i : list) { ... }


Enumerated Types

� Safer than emulated enumerations with constants

public enum StopLight { red, amber, green }

StopLight t=StopLight.red;StopLight t=1;//errorStopLight t=StopLight.blue; //error


Co-variant Return Types

� 1.4 Versionpublic class MyDialog {

MyDialog getDialog() {return this;

}}

public class MyFileDialog extends MyDialog{public boolean isDirectory() {}

MyDialog getDialog() {return this;

}}


Co-variant Return Types (2)

5.0 Versionclass MyDialog {MyDialog getDialog() {

return this;}

}

class MyFileDialog extends MyDialog{public boolean isDirectory() {}// was MyDialog getDialog() {MyFileDialog getDialog() {

return this;}

}

MyFileDialog f = new MyFileDialog();System.out.println("fd="+f.getDialog().isDirectory());


Formatted Output

� printf functionality is added to J2SE 5.0 technology─ Compatible with C version─ Helps migrate legacy code

� You can do things like:out.printf(“name count\n”);out.printf(“%s %5d\n”, user,total);

� Note: Use %n instead of \n for platform-independent newline


Formatted Input

� Scanner API provides simplified Input functionality

� C versionscanf(“%s”, name);

scanf(“%d”, age);

� Java VersionScanner s=new Scanner(System.in);

String name= s.next();int age=s.nextInt();s.close();


Varargs

� Allows multiple arguments to be passed into methods

void argtest(String ... args) {for (int i=0;i <args.length; i++) {}

}

//argtest(“test”, “data”);


Concurrency Utilities

� Concurrency Utility Library (JSR-166)─ Being led by Doug Lea─ Locking APIs─ Powerful high-level thread constructs

� Semaphoresfinal private Semaphore s= new Semaphore(1, true)s.acquireUninterruptibly(); //for non-blocking

//use s.acquire()balance=balance+10; //protected values.release(); //return semaphore token


Concurrency Utilities (2)

� Atomic VariablesAtomicInteger balance=new AtomicInteger(10);System.out.println(balance.getAndAdd(10));

� Thread Executorsclass Worker implements Runnable {

public void run() {System.out.println("New Worker");

}}

public class ConThread {

public static void main(String args[]) {Executor e =

Executors.newFixedThreadPool(3);e.execute(new Worker());

}}


“Tiger” Themes




Monitoring and Manageability

� JVM™ Machine Monitoring and Management API (JSR-174)─ Low memory detection─ Allow access to internal VM status─ Heap sizes, gc info, threads, etc.─ Industry standard SNMP and JMX based─ Plugs into existing management consoles

� JMX API (JSR-003)─ MBeanServer part of JRE─ Support for remote management JSR-160─ Works with existing J2EE™ application servers


SNMP Monitoring

� SNMP Out-of-the-Boxjava -Dcom.sun.management.snmp.port=161

-Dcom.sun.management.snmp.trap=162 -Dcom.sun.management.snmp.acl=false -jar

Java2Demo.jar

� Low Memory Traps from JVM-MANAGEMENT-MIBjvmLowMemoryPoolUsageNotifjvmLowMemoryPoolCollectNotif

� Easy to configure─ Set oid jvmMemPoolThreshold


JMX API Monitoring and Management

� JMX Out-of-the-Boxjava -Dcom.sun.management.jmxremote.port=5001-Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false -jar Java2Demo.jar

� Low Memory Notificationsjava.management.memory.threshold.exceeded

� Easy to Configurejava.lang.MemoryPool.TenuredGen.UsageThreshold=16000


Profiling and Diagnostics

� New Profiling API (JSR-163)─ Allows improved performance analysis─ New jvmti native api replaces jvmpi─ Includes bytecode instrumentation─ hprof updated to use jvmti

� Improved diagnostic ability─ Stack trace API─ Fatal Error handling─ Serviceability agent─ JVM internal tools, jstack, jinfo


StackTrace API

� Generating stack traces has been awkward if no console availableNew Stack Trace APIs address this

System.out.println(Thread.getAllStackTraces());

StackTraceElement e[]=Thread.currentThread().getStackTrace();

for (int i=0; i<e.length; i++) {System.out.println(e[i]);

}


Fatal Error Handler

� Start JVM machine with OnError option

-XX:OnError=”command”optional %p used as process id

-XX:OnError="pmap %p"

-XX:OnError="gcore %p; dbx - %p"

-XX:OnError=”gdb %p”

-XX:OnError="cat hs_err_pid%p.log | mailx -s help [email protected]"


Serviceability Agent Connectors

� Java Debug Interface SA Connectors ─ Attach connector to core file ─ Attach connector to hung JVM machine─ Used by JDI aware debug toolsjdb -connect

sun.jvm.hotspot.jdi.SACoreAttachingConnector:javaExecutable=/usr/java/jdk1.5.0/bin/java


jstack Example

� pstack Java extensions (jstack)─ Understands Java programming language

methods, also jmap, jinfo$ jstack -m 3248

...

----------------- t@8 -----------------

0xff29f16c ___lwp_cond_wait + 0x40xfe0cac90 int Monitor::wait(int,long) + 0x3ec0xfe1193cc void CompileBroker::compiler_thread_loop() + 0x3540xfe0f8bbc void JavaThread::run() + 0x2600xfe0cb124 _start + 0x1440xff36b74 _thread_start + 0x40


“Tiger” Themes




Desktop Client

� Continued deployment improvements─ Unified Java Plug-in and Java™ Web Start console

� Continued quality and performance work─ Startup and footprint work─ Direct support for OpenGL®─ XAWT


OpenGL and X11 Toolkit

� OpenGL acceleration for JFC/Swing applications enabled using:

� java -Dsun.java2d.opengl=true -jar Java2D.jar

� Optional fast X11 toolkit called XAWT, enabled on Linux, option on SolarisTM Operating System

� java -Dawt.toolkit=sun.awt.X11.XToolkit -jar Notepad.jar


Desktop Client 3

� Improved GUI look-and-feel support─ Improved Gnome skins support─ Synth skinnable API─ Improved Windows XP look and feel─ Fresh new cross-platform Java technology

look and feel—“Ocean”


Screenshot of Ocean


Features Outside the Themes

� XML, Web Services� Unicode� JDBC API Disconnected Rowsets� Pack200


Core XML Support

� JSR 206 JAXP 1.3─ XML 1.1 and Namespace─ XML Schema─ XSLT/XSLTC─ SAX 2.0.2─ DOM level 3


Java Web Services Developer Pack

� Commitment to latest Web Services standards � JAX-RPC and SAAJ (WSDL/SOAP)� JAXB� XML Security─ Encryption and Digital Signature

� JAXR


Unicode Supplementary Characters

� Unicode 3.1 adds extra characters─ Some characters don’t fit in Java “char” 16 bits

� Extended characters are pairs of values─ Encoded in a string

� Character still uses 16 bits, includes supplementary int methods

� J2SE 5.0 technology supports Unicode 4.2


JDBC Disconnected RowSets

� CachedRowSet─ Contains in-memory collection of rows─ Allows disconnected use of data─ Updates can be resynchronized into database

� WebRowSet─ Can also import and export XML representation


JDBC Rowset Example

CachedRowSetImpl rowSet = new CachedRowSetImpl();rowSet.setUsername("postgres");rowSet.setPassword("duke");rowSet.setUrl("jdbc:postgresql:test");rowSet.setCommand("SELECT * FROM users");rowSet.execute();

... rowSet.first(); //Select the first rowrowSet.updateInt(2,id+1); //Set the fieldrowSet.updateRow(); //mark row as donerowSet.acceptChanges(); //batch up to database


Pack200

� JAR File Compression API and Tool

� javax.pack.Pack200 classpack200, unpack200 command line tools

� pack200 -v charsets.pack.gz charsets.jar

� unpack200 -v charsets.pack.gz charsets.jar


Summary

� This was a fast-track overview─There are over 100 features

� Watch out for “Tiger”!─ Performance, ease of development,

RAS and Desktop Client


Q&A

Calvin Austin


Further Information

� http://java.sun.com/j2se/1.5.0

� http://jcp.org/en/jsr/detail?id=176

java.sun.com/javaone/sf


Fast Track to Java™ 2 Platform, Standard Edition (J2SE™) 5.0 Technology

Calvin Austin J2SE 5.0 Specification LeadSun Microsystems, Inc.

j2se5.0

Documents

backward source compatibility

performance work

tiger j2se

java platform

quality lots

manageability desktop

key features of j2se

tiger component jsrs