J2SE5 by Luqman

8/6/2019 J2SE5 by Luqman

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J2SE 5.0Tiger


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J2SE Road Map

Version Code Name Release Date

JDK 1.1.4

JDK 1.1.5

JDK 1.1.6

JDK 1.1.7JDK 1.1.8

J2SE 1.2

J2SE 1.2.1

J2SE 1.2.2

J2SE 1.3

J2SE 1.3.1

J2SE 1.4.0

J2SE 1.4.1

J2SE 1.4.2

Sparkler

Pumpkin

Abigail

BrutusChelsea

Playground

(none)

Cricket

Kestrel

Ladybird

Merlin

Hopper

Mantis

Sept 12, 1997

Dec 3, 1997

April 24, 1998

Sept 28, 1998April 8, 1999

Dec 4, 1998

March 30, 1999

July 8, 1999

May 8, 2000

May 17, 2001

Feb 13, 2002

Sept 16, 2002

June 26, 2003

J2SE 5.0 (1.5.0) Tiger Sept 29, 2004


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J2SE Themes

J2SE 1.4.0 - Quality(Merlin)

J2SE 5.0 - Ease of Development

(Tiger)

J2SE 6.0 - Becoming more open

(Mustang) (Java goes multilingual)


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Theme forJ2SE 5.0

Ease of development

Quality

Monitoring and Manageability

Performance and Scalability

Desktop Client


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New Features in J2SE 5.0

Language Features

Virtual Machine Features

Performance Enhancements

Base Libraries

Integration Libraries


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Language Features



Base Libraries



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Language Features

Generics

Enhanced forLoop Variable Arguments

Boxing / Unboxing

Type-safe enumerations Static import


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Generics

A way to make class type-safe that are

written on any arbitrary object type.

Allows to narrow an instance of a Collection

to hold a specific object type and eliminating

the need to typecast it while retrieving the

object.


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J2SE 1.4.0

ArrayList intList = new ArrayList();

intList.add(new Integer(0));

Integer intObj = (Integer) intList.get(0);

J2SE 5.0

ArrayList intList = new ArrayList();intList.add(new Integer(0)); // Only Integer Objects allowed

Integer intObj = intList.get(0); // No need to Type Cast


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Enhanced for Loop

Iterating over collections is a pain.

Often, iterator is unused except to get elements. Iterators are error-prone.

Iterator variable occurs three times per loop.

Gives you two opportunities to get it wrong.

Common cut-and-paste error. Wouldnt it be nice if the compiler took care of the

iterator for you?


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J2SE 1.4.0

for(Iterator iter = myArray.iterator(); iter.hasNext(); ){

MyClass myObj = (MyClass)iter.next();

myObj.someOperation();

}

J2SE 5.0

for(MyClass myObj : myArray){

myObj.someOperation();

}


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// Returns the sum of the elements of a

int sum(int[] a)

{

int result = 0;

for (int i : a)

result += i;

return result;

}

For Arrays

Eliminates array index rather than iterator

Similar advantages


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Variable Arguments

To write a method that takes an arbitrary

number of parameters, you must use anarray.

Creating and initializing arrays is a pain.

Why not complier take care of it?


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public int sum(int... intList){int i, sum;

sum=0;

for(i=0; i


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Boxing / Unboxing

Collections hold only objects, so to put

primitive data types it needs to be wrappedinto a class, like int to Integer.

It is a pain to wrap and unwrap.

Wouldnt it be nice if the compiler took care

of it for you?


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J2SE 1.4.0

ArrayList arrayList = new ArrayList();

Integer intObject = new Integer(10);

arrayList.add(intObject);// cannot add 10 directly

J2SE 5.0

ArrayList arrayList = new ArrayList();

arrayList.add(10);// int 10 is automatically wrapped into Integer


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Type-safe enumerations

Compiler support for Typesafe Enum pattern.

Looks like traditional enum (C, C++, Pascal). Far more powerful.

Can be used in switch/case statements.

Can be used in for loops.


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An enumeration is an ordered list of items wrapped into a

single entity.

enum Season {winter, spring, summer, fall}

UsageE

xamplefor (Season s : Season.VALUES){

//

}

An enumeration (abbreviated enum in Java) is a special type of class.

All enumerations implicitly subclass a new class in Java,java.lang.Enum.

This class cannot be subclassed manually.


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Static import

Ability to access static members from a class

without need to qualify them with a classname.


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interface ShapeNumbers {

public static int CIRCLE = 0;public static int SQUARE = 1;

public static int TRIANGLE = 2;

}

Implementing this interface creates an unnecessary dependence on

the ShapeNumbers interface.

It becomes awkward to maintain as the class evolves, especially if

other classes need access to these constants also and implement this

interface


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To make this cleaner, the static members are placed into a class and

then imported via a modified syntax of the import directive.

package MyConstants;

class ShapeNumbers {

public static int CIRCLE = 0;

public static int SQUARE = 1;

public static int TRIANGLE = 2;}

To import the static members in your class, specify the following in the import section

of yourJava source file.

import static MyConstants.ShapeNumbers.*;// imports all static data

You can also import constants individually by using the following syntax:

import static MyConstants.ShapeNumbers.CIRCLE;

import static MyConstants.ShapeNumbers.SQUARE;


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Language Features



Base Libraries



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Class Data Sharing

Server-Class Machine Detection Garbage Collector Ergonomics

Thread Priority Changes

High-Precision Timing Support


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Class Data Sharing

Reduces startup time of java applications.

Better results for smaller applications. Automatically enabled when conditions allow it to

be used.

Not supported in Microsoft Windows 95/98/ME.


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How CDS Works :

When JRE is installed on 32-bit platforms using the Sun providedinstaller, it loads a set of classes from the system jar file into a

private internal representation, and dumps that representation to a

file, called a "shared archive".

Unix : jre/lib/[arch]/client/classes.jsa

Windows : jre/bin/client/classes.jsa

During subsequent JVM invocations, the shared archive is

memory-mapped in, saving the cost of loading those classes and

allowing much of the JVM's metadata for these classes to be

shared among multiple JVM processes.

CDS produces better results for smaller applications because it

eliminates a fixed cost of loading certain core classes.


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The footprint cost of new JVM instances has been

reduced in two ways.

First, a portion of the shared archive, currently 5-6 MB, is

mapped read-only and therefore shared among multiple

JVM processes. Previously this data was replicated in

each JVM instance.

Second, since the shared archive contains class data in

the form in which the Java VM uses it, the memory which

would otherwise be required to access the original class

information in rt.jar is not needed.

These savings allow more applications to be run concurrently

on the same machine.


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Server-Class Machine Detection

At startup Launcher automatically detects if

application is running on server-class Machine.

Uses ServerVM / Client VM accordingly.

Server-class Machine : One with at least 2 CPUs and

at least 2GB of physical memory.

ServerVM start more slowly than client VM, but over time runs

more quickly.


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Garbage CollectorErgonomics

On server-class machines running the server VM,

the garbage collector (GC) has changed from the

previous serial collector to a parallel collector.

Can switch the GC collector mode using the

command-line option.

XX:+UseSerialGC - Serial collector

XX:+UseParallelGC - Parallel collector


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Thread Priority Changes

Java threads and Native threads to compete on equalfooting.

Java threads at NORM_PRIORITY can now competeas expected with native threads.

Java priorities in the range [10...5] are all mapped to the

highest possible TS (timeshare) or IA (interactive)priority.

Priorities in the range [1..4] are mapped tocorrespondingly lower native TS or IA priorities


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High-Precision Timing Support

System.nanoTime() method added.

Provides access to nanosecond granularity

time source for relative time measurements.

The actual precision of the time value

returned is platform dependant.


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Language Features



Base Libraries



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Garbage collection Ergonomics

StringBuilder Class Java 2D Technology

Image I/O


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Garbage collection Ergonomics

Automatic detection of Sever-Class Machine

Using Client / ServerVM accordingly. Parallel Garbage Collection

Default parallel garbage collection on ServerVM.


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StringBuilder Class

Introduced a new classjava.lang.StringBuilder.

It is like unsunchronized StringBuffer. Faster than StringBuffer.


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Java 2D Technology

Improved acceleration for Buffered Image

Objects Support for H/W accelerated rendering using

OpenGL.

Improved text-rendering performance.


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Image I/O

Improved Performance and memory usage

while reading and writing JPEG Images.

In mage I/O API (javax.imageio) added

support for reading and writing BMP and

WBMP images.


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Language Features



Base Libraries



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Base Libraries

Lang and Util Packages

Networking JAXP

Bit Manipulation Operations


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Lang and Util Packages

ProcesBuilder More convenient way to invoke sub processes than Runtime.exec

Formatter printfstyle format strings.

Support for layout justification and alignment, common formats for

numeric, string and date/time data.

Scanner Converts text into primitives or Strings.

regular expression based searches on streams, file data,

strings.


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Lang and Util Packages contd

Instrumentation

New packagejava.land.instrument, allows javaprogramming agents to instrument programs running on the

Java virtual machine by modifying methods' bytecodes at

runtime

Threads

getState() for querying the execution state of a thread. getStackTrace to obtain stack trace of a thread.

A new form of the sleep() method is provided which allows

for sleep times smaller than one millisecond.


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Networking

Complete support for IPv6 on Windows XP

(sp1) and 2003. ping like feature InetAddress class

provides API to test the reachability of a host.

Improved Cookie support.

Proxy Sever Configuration ProxySelector

API provides dynamic proxy configuration.


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JAXP 1.3

A built-in validation processor forXML Schema.

XSLTC, the fast, compiling transformer, which is nowthe default engine for XSLT processing.

Java-Centric XPathAPIs injavax.xml.xpath, which

provide a more java-friendly way to use an XPath

expression.

Grammar pre-parsing and caching, which has a

major impact on performance for high-volume XML

processing.


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Bit Manipulation Operations

The wrapper classes (Integer, Long, Short, Byte, andChar) now support common bit manipulation

operations like highestOneBit,

lowestOneBit,

numberOfLeadingZeros,

numberOfTrailingZeros,

bitCount, rotateLeft,

rotateRight,

reverse,

signum, and

reverseBytes.


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Language Features



Base Libraries



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Remote Method Invocation (RMI)

Java Database Connectivity (JDBC) Java Naming and Directory Interface (JNDI)


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Remote Method Invocation (RMI)

Dynamic Generation of Stub Classes G

eneration of stub at runtime eliminated the need of stubcompilerrmic.

Standard SSL/TLS Socket Factory Classes Standard Java RMI socket factory classes,

javax.rmi.ssl.SslRMIClientSocketFactory and

javax.rmi.ssl.SslRMIServerSocketFactory added. Communicate over the Secure Sockets Layer (SSL) or

Transport Layer Security (TLS) protocols using the Java

Secure Socket Extension (JSSE).


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Java Database Connectivity (JDBC)

RowSetinterface has been implemented in five

common ways a RowSet object can be used.

JdbcRowSet- used to encapsulate a result set or a driver.

CachedRowSet- disconnects from its data source and operatesindependently except when it is getting data from the data source

or writing modified data back to the data source.

FilteredRowSet- extends CachedRowSet and is used to get a

subset of data.

JoinRowSet- extends CachedRowSet and is used to get anSQL JOIN of data from multiple RowSet objects.

WebRowSet- extends CachedRowSet and is used for XMLdata.


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Q & ATiger


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Thank You

Documents

J2SE5 by Luqman