Java Language
Java is a programming language originally developed by James Gosling at Sun Microsystems and launched in 1995 as one of the main components of the platform in the company Sun Microsystems Java. Language comes most of the syntax of C and C + +, but it is a model of simple objects and fewer low-level objects. Typically compiled into Java bytecode (class file), which can run on any virtual machine, Java (JVM), regardless of computer architecture.
The original machine and a reference implementation of compilers, Java, virtual and class libraries were developed by Sun in 1995. Since May 2007, as stated in the Java Community Process, Sun Java Most relicensed under the GNU General Public License. Other countries have also developed the implementation of these alternative technologies for the Armed Forces, such as the GNU Compiler for Java and GNU CLASSPATH.
James Gosling initiated the project in Java in June 1991 for use in one of his numerous television projects field. Language was initially called Oak after a tree that stood outside the office Gosling also went by the name of the green and came later renamed Java, from a list of random words. Gosling to implement a virtual machine and language that are familiar C / C + + style of notation.
Sunday launched the first public implementation, Java 1.0 in 1995. He promised "Write Once, Run Anywhere" (WORA), offering no cost run-time on popular platforms. Enough to distinguish between safe and configurable security enabled network and file access. Major web browsers soon incorporated the ability to run Java applets on Web pages and Java quickly became popular. With the advent of Java 2 (released initially in J2SE 1.2, in December 1998), new versions have been built several configurations for different types of platforms. For example, the target enterprise application J2EE and largely stripped-down version for J2ME mobile applications. J2SE appointed Standard Edition. In 2006, for marketing purposes, Sun renamed in November J2 versions as Java EE, Java ME and Java SE, respectively.
In 1997, Sun Microsystems approached ISO / IEC JTC1 standards body and later the Ecma International officially Java, but soon withdrew from the process. Java-remains the de facto standard is controlled via the Java Community Process. At one time, Sun made most of its Java implementations available without charge, despite their status as proprietary software. Sunday Income from Java, through the sale of licenses for specialized products, such as the Java Enterprise System. Sunday distinction between its Software Development Kit (SDK) and Runtime Environment (JRE) (a subset of the SDK), the main differences do not result in the compiler JDK, useful programs and header files.
On November 13, 2006 Sun released much of Java as open source under GNU General Public License (GPL). On May 8, 2007 Sunday over the process that makes the whole code is available on the basis of the free software Java / open source terms of distribution, but a small portion of code that Sun did not hold the copyrights.
Sun vice president Rich Green said that Sun is an ideal role in terms of Java is that the evangelist "[13].
Guidelines
There were five main objectives in creating the language Java: [14]
1.It should be "simple, object-oriented, and familiar.
2.It should be "safe and secure.
3.It should be "architecture neutral and portable.
4.It should work with "high performance".
5.It should be "interpreted, threaded, and dynamic.
Java Platform
One feature of Java is portability, which means that programs written in Java Similarly, you should run on any hardware / OS platform. This is achieved by compiling Java code intermediate representation called byte-code Java, and not directly to a particular platform is computer code. Java bytecode instructions are similar to native code, but they are intended to be interpreted by the virtual machine (VM), written specifically for the receiving equipment. End users typically use Java Runtime Environment (JRE), installed on their computer for offline applications, Java, or web browser to run applets Java.
The standard library provides a common way to access specific objects, such as graphics, threading and networking.
The main advantage of machine code is a port. However, the overhead of interpretation means that almost always interpreted programs run slower than programs compiled to native executables should be, and Java has suffered a reputation for poor performance. This gap was reduced to a series of optimization methods introduced in the latest JVM implementation.
Running Java
Sun Microsystems official license for Java Standard Edition platform for Linux, Mac OS X and Solaris [citation needed]. While in the past, Sun has a license for Java Microsoft, the license expired and was not renewed. Through a network of suppliers and third licensees, alternative Java environments are available for these and other platforms.
License to use Sun Java brand insists that all implementations be "compatible". This led to a legal dispute with Microsoft after Sunday claimed that the introduction of Microsoft were not in favor of RMI or JNI, and added features of the platform of their own. Sun suit in 1997 and in 2001 received permission to U.S. $ 20 million, and the court of licensing conditions in the BC As a result, Microsoft is not shipping Java with Windows, such as recent versions of Windows, Internet Explorer does not support Java applets without a third party Plug-In . Sun, and others were freely available Java Run-time for these systems and other windows.
Platform independent Java-is important for the Java EE strategy and more rigorous testing required for certification. This environment enables portable server applications effects, such as Web services, Java Servlets and Enterprise JavaBeans, and integrated systems based on OSGi, using an embedded Java environment. The new project GlassFish, Sun seeks to create a fully functional implementation of a single Open Source Java EE technologies.
Sunday also called extensions JRE Java Development Kit (commonly known as the JDK), which includes development tools such as compiler Java, Javadoc, Jar and debugger.
Java Performance
Programs written in Java was considered to be slower and require more memory than those written in other languages. [18] However, the speed of Java programs "significantly improved with the introduction of the principle of" just-in-time compilation in 1997-1998 to add the capabilities of the Java language support for better analysis and code optimization in Java Virtual machine itself, as the Sun HotSpot JVM is becoming to default in 2000.
Java memory management
Java uses garbage collector for automatic memory management life cycle objects. The programmer determines when objects are created and the Java runtime is responsible for the recovery of memory after the object is no longer used. As soon as any reference to the object remains inaccessible memory is right to be issued automatically by the garbage collector. Something similar to a memory leak may still occur if the code a programmer has a reference to an object that is no longer necessary, usually when no longer needed objects are stored in containers that are still in use. If the methods of existing objects is called a null pointer exception "thrown.
One of the ideas behind Java model of automatic memory management that programmers will be spared the burden of having to perform manual memory management. In some languages, to create a memory object is allocated on the stack implicitly or explicitly allocated and freed from the work area. However, the memory management is the responsibility of the programmer. If the program does not free the object memory leak. If a program tries to access or release the memory that was already released, the result will be uncertain and difficult to predict, and the program can become unstable and / or accident. This can be partly remedied by the use of smart indicators, but they add overhead and complexity. Note that does not prevent garbage collection 'logical memory loss ", that is, the memory is still a reference, but never used.
Garbage collection can occur at any time. Ideally, this will occur when the program is inactive. It is guaranteed to be triggered if there is sufficient free memory in the heap to allocate a new object, it can cause the program to lock momentarily. Explicit memory management is not possible in Java.
Java does not support C / C + + style pointer arithmetic, where the object addresses and signatures of integers (usually long integers) can be used as synonyms. This allows the garbage collector is used to move objects, and provides type safety.
As in C + + and other object-oriented languages, variables are Java primitive data types are not objects. Values of primitive types are stored directly in the fields (objects) or on the stack (for methods), but not in the workplace, as is usually applied to objects (see, but Escape analysis). This was a conscious decision Java developers to improve performance. For this reason, Java does not take a purely object-oriented language. However, as of Java 5.0, which allows developers to proceed as autoboxing primitive type, where the cases of their wrapper classes.
Java syntax
Java syntax is largely derived from C + +. Unlike C + +, which combines the syntax for structured, general and object-oriented programming, Java was built almost exclusively as an object-oriented language. All codes are written inside the class and everything is an object, except for internal data types (ordinal and real boolean values, and character), not classes for performance reasons.
Java suppresses some functions (such as operator overloading and multiple inheritance) classes in order to simplify the language and to prevent possible errors and anti-model.
Java uses the same methods as C + + comments. There are two different styles of comments: single line style, marked by two forward slashes before, and style multiple lines opened with a slash asterisk (/ *) and closed with a slash asterisk (*/).
Java Class Library
Java byte-code libraries compile the source code developed for the implementation of the JRE to support the development of applications in Java. Examples of such libraries are:
Main library, including:
Collections of libraries that implement data structures such as lists, dictionaries, trees and sets
Processing XML (parsing, processing, validation) libraries
Safety
Library of internationalization and localization
Integration libraries to the application writer to communicate with external systems. These libraries include:
Java Database Connectivity (JDBC) API for database access
Java Naming and Directory Interface (JNDI) for search and detection
RMI and CORBA for distributed application development
JMX management and monitoring applications
UI libraries, including:
(Heavy weight, or native) Abstract Window Toolkit (AWT), which provides GUI components, tools for creating these components and means of handling events from those components
(Light) Swing libraries, which are built on AWT but provide (native) implementations of AWT widgetry
API for audio capture, processing and reproduction
Platform-dependent implementation of the virtual machine Java (JVM), which is the means through which runs Java byte code libraries and third-party applications
Plug-ins that will allow the applet will run in Web browsers
Java Web Start, which allows applications to Java, to be efficiently distributed to end users on the Internet
Licensing and documentation.
Java Editions
Sunday identified and supported the four editions of applications Java, designed for different environments and segmented many of its API for this, that they are one of the platforms. Platform:
Java Card for smart cards.
Java Platform, Micro Edition (Java ME) - targeting environments with limited resources.
Java Platform, Standard Edition (Java SE) - targeting workstation.
Java Platform, Enterprise Edition (Java EE) - targeting large distributed enterprise environments, or the Internet.
Classes in the Java API for organized into separate groups called packages. Each package contains a set of related interfaces, classes and exceptions. Refers to a single platform for the description of available packages.
A set of API to control Sun Microsystems, in collaboration with others in the program Java Community Process. Companies or individuals involved in this process may affect the design and development of API. This was the subject of controversy.
http://www.wwworldwidewebdesigner.com
The original machine and a reference implementation of compilers, Java, virtual and class libraries were developed by Sun in 1995. Since May 2007, as stated in the Java Community Process, Sun Java Most relicensed under the GNU General Public License. Other countries have also developed the implementation of these alternative technologies for the Armed Forces, such as the GNU Compiler for Java and GNU CLASSPATH.
James Gosling initiated the project in Java in June 1991 for use in one of his numerous television projects field. Language was initially called Oak after a tree that stood outside the office Gosling also went by the name of the green and came later renamed Java, from a list of random words. Gosling to implement a virtual machine and language that are familiar C / C + + style of notation.
Sunday launched the first public implementation, Java 1.0 in 1995. He promised "Write Once, Run Anywhere" (WORA), offering no cost run-time on popular platforms. Enough to distinguish between safe and configurable security enabled network and file access. Major web browsers soon incorporated the ability to run Java applets on Web pages and Java quickly became popular. With the advent of Java 2 (released initially in J2SE 1.2, in December 1998), new versions have been built several configurations for different types of platforms. For example, the target enterprise application J2EE and largely stripped-down version for J2ME mobile applications. J2SE appointed Standard Edition. In 2006, for marketing purposes, Sun renamed in November J2 versions as Java EE, Java ME and Java SE, respectively.
In 1997, Sun Microsystems approached ISO / IEC JTC1 standards body and later the Ecma International officially Java, but soon withdrew from the process. Java-remains the de facto standard is controlled via the Java Community Process. At one time, Sun made most of its Java implementations available without charge, despite their status as proprietary software. Sunday Income from Java, through the sale of licenses for specialized products, such as the Java Enterprise System. Sunday distinction between its Software Development Kit (SDK) and Runtime Environment (JRE) (a subset of the SDK), the main differences do not result in the compiler JDK, useful programs and header files.
On November 13, 2006 Sun released much of Java as open source under GNU General Public License (GPL). On May 8, 2007 Sunday over the process that makes the whole code is available on the basis of the free software Java / open source terms of distribution, but a small portion of code that Sun did not hold the copyrights.
Sun vice president Rich Green said that Sun is an ideal role in terms of Java is that the evangelist "[13].
Guidelines
There were five main objectives in creating the language Java: [14]
1.It should be "simple, object-oriented, and familiar.
2.It should be "safe and secure.
3.It should be "architecture neutral and portable.
4.It should work with "high performance".
5.It should be "interpreted, threaded, and dynamic.
Java Platform
One feature of Java is portability, which means that programs written in Java Similarly, you should run on any hardware / OS platform. This is achieved by compiling Java code intermediate representation called byte-code Java, and not directly to a particular platform is computer code. Java bytecode instructions are similar to native code, but they are intended to be interpreted by the virtual machine (VM), written specifically for the receiving equipment. End users typically use Java Runtime Environment (JRE), installed on their computer for offline applications, Java, or web browser to run applets Java.
The standard library provides a common way to access specific objects, such as graphics, threading and networking.
The main advantage of machine code is a port. However, the overhead of interpretation means that almost always interpreted programs run slower than programs compiled to native executables should be, and Java has suffered a reputation for poor performance. This gap was reduced to a series of optimization methods introduced in the latest JVM implementation.
Running Java
Sun Microsystems official license for Java Standard Edition platform for Linux, Mac OS X and Solaris [citation needed]. While in the past, Sun has a license for Java Microsoft, the license expired and was not renewed. Through a network of suppliers and third licensees, alternative Java environments are available for these and other platforms.
License to use Sun Java brand insists that all implementations be "compatible". This led to a legal dispute with Microsoft after Sunday claimed that the introduction of Microsoft were not in favor of RMI or JNI, and added features of the platform of their own. Sun suit in 1997 and in 2001 received permission to U.S. $ 20 million, and the court of licensing conditions in the BC As a result, Microsoft is not shipping Java with Windows, such as recent versions of Windows, Internet Explorer does not support Java applets without a third party Plug-In . Sun, and others were freely available Java Run-time for these systems and other windows.
Platform independent Java-is important for the Java EE strategy and more rigorous testing required for certification. This environment enables portable server applications effects, such as Web services, Java Servlets and Enterprise JavaBeans, and integrated systems based on OSGi, using an embedded Java environment. The new project GlassFish, Sun seeks to create a fully functional implementation of a single Open Source Java EE technologies.
Sunday also called extensions JRE Java Development Kit (commonly known as the JDK), which includes development tools such as compiler Java, Javadoc, Jar and debugger.
Java Performance
Programs written in Java was considered to be slower and require more memory than those written in other languages. [18] However, the speed of Java programs "significantly improved with the introduction of the principle of" just-in-time compilation in 1997-1998 to add the capabilities of the Java language support for better analysis and code optimization in Java Virtual machine itself, as the Sun HotSpot JVM is becoming to default in 2000.
Java memory management
Java uses garbage collector for automatic memory management life cycle objects. The programmer determines when objects are created and the Java runtime is responsible for the recovery of memory after the object is no longer used. As soon as any reference to the object remains inaccessible memory is right to be issued automatically by the garbage collector. Something similar to a memory leak may still occur if the code a programmer has a reference to an object that is no longer necessary, usually when no longer needed objects are stored in containers that are still in use. If the methods of existing objects is called a null pointer exception "thrown.
One of the ideas behind Java model of automatic memory management that programmers will be spared the burden of having to perform manual memory management. In some languages, to create a memory object is allocated on the stack implicitly or explicitly allocated and freed from the work area. However, the memory management is the responsibility of the programmer. If the program does not free the object memory leak. If a program tries to access or release the memory that was already released, the result will be uncertain and difficult to predict, and the program can become unstable and / or accident. This can be partly remedied by the use of smart indicators, but they add overhead and complexity. Note that does not prevent garbage collection 'logical memory loss ", that is, the memory is still a reference, but never used.
Garbage collection can occur at any time. Ideally, this will occur when the program is inactive. It is guaranteed to be triggered if there is sufficient free memory in the heap to allocate a new object, it can cause the program to lock momentarily. Explicit memory management is not possible in Java.
Java does not support C / C + + style pointer arithmetic, where the object addresses and signatures of integers (usually long integers) can be used as synonyms. This allows the garbage collector is used to move objects, and provides type safety.
As in C + + and other object-oriented languages, variables are Java primitive data types are not objects. Values of primitive types are stored directly in the fields (objects) or on the stack (for methods), but not in the workplace, as is usually applied to objects (see, but Escape analysis). This was a conscious decision Java developers to improve performance. For this reason, Java does not take a purely object-oriented language. However, as of Java 5.0, which allows developers to proceed as autoboxing primitive type, where the cases of their wrapper classes.
Java syntax
Java syntax is largely derived from C + +. Unlike C + +, which combines the syntax for structured, general and object-oriented programming, Java was built almost exclusively as an object-oriented language. All codes are written inside the class and everything is an object, except for internal data types (ordinal and real boolean values, and character), not classes for performance reasons.
Java suppresses some functions (such as operator overloading and multiple inheritance) classes in order to simplify the language and to prevent possible errors and anti-model.
Java uses the same methods as C + + comments. There are two different styles of comments: single line style, marked by two forward slashes before, and style multiple lines opened with a slash asterisk (/ *) and closed with a slash asterisk (*/).
Java Class Library
Java byte-code libraries compile the source code developed for the implementation of the JRE to support the development of applications in Java. Examples of such libraries are:
Main library, including:
Collections of libraries that implement data structures such as lists, dictionaries, trees and sets
Processing XML (parsing, processing, validation) libraries
Safety
Library of internationalization and localization
Integration libraries to the application writer to communicate with external systems. These libraries include:
Java Database Connectivity (JDBC) API for database access
Java Naming and Directory Interface (JNDI) for search and detection
RMI and CORBA for distributed application development
JMX management and monitoring applications
UI libraries, including:
(Heavy weight, or native) Abstract Window Toolkit (AWT), which provides GUI components, tools for creating these components and means of handling events from those components
(Light) Swing libraries, which are built on AWT but provide (native) implementations of AWT widgetry
API for audio capture, processing and reproduction
Platform-dependent implementation of the virtual machine Java (JVM), which is the means through which runs Java byte code libraries and third-party applications
Plug-ins that will allow the applet will run in Web browsers
Java Web Start, which allows applications to Java, to be efficiently distributed to end users on the Internet
Licensing and documentation.
Java Editions
Sunday identified and supported the four editions of applications Java, designed for different environments and segmented many of its API for this, that they are one of the platforms. Platform:
Java Card for smart cards.
Java Platform, Micro Edition (Java ME) - targeting environments with limited resources.
Java Platform, Standard Edition (Java SE) - targeting workstation.
Java Platform, Enterprise Edition (Java EE) - targeting large distributed enterprise environments, or the Internet.
Classes in the Java API for organized into separate groups called packages. Each package contains a set of related interfaces, classes and exceptions. Refers to a single platform for the description of available packages.
A set of API to control Sun Microsystems, in collaboration with others in the program Java Community Process. Companies or individuals involved in this process may affect the design and development of API. This was the subject of controversy.
http://www.wwworldwidewebdesigner.com
1.3.1
1.4.2
activex
android
applet
application
applications
arcade
array
arraylist
asp.net
bonus
boolean
button
class
codes
coffee
coffee house
coffee shop
coldfusion
compiler
component
computer
computer programming
computers
constructor
consultant
convert
database
design
developer
documentation
dotnet
download
downloads
ebooks
equals
event
example
examples
exception
extends
flash
flash games
frame
free games
games
gourmet coffee
graphics
hacking
hardware
hashmap
hashtable
hibernate
hosting
image
import
information technology
install
integer
interface
internet
it jobs
it training
iterator
javadoc
jframe
jpanel
jtable
linux
method
methods
microsoft
mobile
mobile games
music
network
networking
object
online
open source
outsourcing
package
plugin
plugins
programmer
programmers
programming
project
project manager
public
recruitment
resume
ringtones
ruby on rails
sample
screensavers
script
scripts
servlet
software
software consulting
software developer
software development
software engineering
software outsourcing
software testing
source code
spring
static
string
struts
summary
symbian
systems
technology
thread
tostring
training
tutorial
tutorials
using
version
video
visual basic
visual c
visual studio
wallpapers
web design
web designing
web development
web hosting
weblogic
website
website design
website development
websites
websphere
win32
window
windows
1.4.2
activex
android
applet
application
applications
arcade
array
arraylist
asp.net
bonus
boolean
button
class
codes
coffee
coffee house
coffee shop
coldfusion
compiler
component
computer
computer programming
computers
constructor
consultant
convert
database
design
developer
documentation
dotnet
download
downloads
ebooks
equals
event
example
examples
exception
extends
flash
flash games
frame
free games
games
gourmet coffee
graphics
hacking
hardware
hashmap
hashtable
hibernate
hosting
image
import
information technology
install
integer
interface
internet
it jobs
it training
iterator
javadoc
jframe
jpanel
jtable
linux
method
methods
microsoft
mobile
mobile games
music
network
networking
object
online
open source
outsourcing
package
plugin
plugins
programmer
programmers
programming
project
project manager
public
recruitment
resume
ringtones
ruby on rails
sample
screensavers
script
scripts
servlet
software
software consulting
software developer
software development
software engineering
software outsourcing
software testing
source code
spring
static
string
struts
summary
symbian
systems
technology
thread
tostring
training
tutorial
tutorials
using
version
video
visual basic
visual c
visual studio
wallpapers
web design
web designing
web development
web hosting
weblogic
website
website design
website development
websites
websphere
win32
window
windows
