Do you knew all 60 keywords of java?????????????.

1. abstract 
2. boolean
3. break
4. byte
5. by value
6. case
7. cast 
8. catch
9. char
10. class
11. const
12. continue
13. default
14. do
15. double
16. else
17. extends
18. false
19. final
20. finally
21. float
22. for
23. future
24. generic
25. goto
26. if
27. implements
28. import
29. inner
30. instanceof
31. int
32. interface
33. long
34. native
35. new
36. null
37. operator
38. outer
39. package
40. private
41. protected
42. public
43. rest
44. return
45. short
46. static
47. super
48. switch
49. synchronized
50. this
51. threadsafe
52. throw
53. throws
54. transient
55. true
56. try
57. var
58. void
59. volatile
60. while

Easy explanation about features of java

FEATURES OF JAVA

1. Simple
   
       It is simple because of the following factors:

• free from pointer.
• It have Rich set of API (application protocol interface).
• Introduction of Garbage Collector.
• It contains user friendly syntax for developing any applications.

2.Platform Independent

A program or technology is said to be platform independent if and only if which can run on all available operating systems with respect to its development and compilation. Here  platform represents O.S

3. Architectural Neutral

Architecture represents processor.

A Language is said to be Architectural neutral which can run on any available processors in the real world without considering there architecture and vendor (providers) irrespect to its development and compilation.

4. Portable

If any language supports platform independent and architectural neutral feature known as portable. 

                             Platform independent+architecture neutral=portable

5. Multi threaded

When any Language execute multiple thread at a time that language is known as multithreaded Language. 

6. Distributed

In distributed application multiple client system are depends on multiple server systems so that even problem occurred in one server will never be reflected on any client system.
Best eg: internet applications

7. Robust

Robust means strong i.e, java is a strong Programming Language because of its capability to handle Run-time Error, automatic garbage collection, lack of pointer concept, Exception Handling. All these points makes It robust Language.

8. Dynamic

It support Dynamic memory allocation. The process of allocating the memory space to the input of the program at a run-time is known as dynamic memory allocation, We use an operator called 'new' 'new' operator for dynamic memory allocation which is also known as dynamic memory allocation operator

9. Secure

It is more secured language compare to c and c++. In this language all code is covered into byte code after compilation which can not be understood by human.

10. High performance

It have high performance because of following reasons;

•  uses Bytecode which is more faster than ordinary pointer code so Performance of this language is high.
• Garbage collector, collect the unused memory space and improve the performance of application.
• It have no pointers so that using this language we can develop an application very easily.
• It support multithreading, because of this time consuming process can be reduced to execute the program.

Why jdk jre and jvm??????? is it needed to devide them and explain??

The program developer needs to develop the code and execute the program i.e, verify the codeand provide a runtime environment 

but the user need not be considered about all those. They are just considered about the execution of the code.

HIERARCHY OF JDK JRE AND JVM :

JDK consists of JRE and JRE consists of JVM

What is JDK:

• JDK stands for java development kit 
• JDK consists of both compiler and JRE 
• For a programmer to write the source code, compile and then execute the program Jdk is used
• JDK is the set of Compiler and JRE

Then what is JRE

• JRE stands for Java runtime environment 
• It has only Jvm 
• That means using JRE we can only execute programs

Note: we can download jre as different application

Now comment what programmers use and what clients use?

Simple explanation on java programdevelopment,compilation and executution procedre u

             In the java programing language,all source code is first written in plain text files ending with the ".java" extension. Those source files are thencompiled into ".class" files by the javac compiler. ".class file doesnt contain code that is native to your processor, it instead contains byte codes.
                   the native language of the JVM. The java launcher tool then runs your application with an instance of the JAVA VIRTUAL MACHINE

                  DIAGRAM SHOWING JAVA PROGRAM COMPILATION AND EXECUTION

What is the solution for achieving platform independency / Why only java is plaform independent?

Its very simple, generate machine language for the client OS. Machine language generation must be moved from compilation phase to execution phase, Because client OS is known only at the time of execution
                   This is how JAVA achieved platform independency




                                     

JAVA history(easy to understand)

HISTORY OF JAVA

Java history is interesting to know. The history of java starts from Green Team. Java team members (also known as Green Team), initiated a revolutionary task to develop a language for digital devices such as set-top boxes, televisions etc.

For the green team members, it was an advance concept at that time. But, it was suited for internet programming. Later, Java technology as incorporated by Netscape.

1) James Gosling, Mike Sheridan, and Patrick Naughton initiated the Java language project in June 1991. The small team of sun engineers called Green Team.Currently, Java is used in internet programming, mobile devices, games, e-business solutions etc. There are given the major points that describes the history of java.

2) Originally designed for small, embedded systems in electronic appliances like set-top boxes.

3) Firstly, it was called "Greentalk" by James Gosling and file extension was .gt.

4) After that, it was called Oak and was developed as a part of the Green project.

Why Oak name for java language?

5) Why Oak? Oak is a symbol of strength and choosen as a national tree of many countries like U.S.A., France, Germany, Romania etc.

6) In 1995, Oak was renamed as "Java" because it was already a trademark by Oak Technologies.

Why Java name for java language?

7) Why they choosed java name for java language? The team gathered to choose a new name. The suggested words were "dynamic", "revolutionary", "Silk", "jolt", "DNA" etc. They wanted something that reflected the essence of the technology: revolutionary, dynamic, lively, cool, unique, and easy to spell and fun to say.

According to James Gosling "Java was one of the top choices along with Silk". Since java was so unique, most of the team members preferred java.

8) Java is an island of Indonesia where first coffee was produced (called java coffee).

9) Notice that Java is just a name not an acronym.

10) Originally developed by James Gosling at Sun Microsystems (which is now a subsidiary of Oracle Corporation) and released in 1995.

11) In 1995, Time magazine called Java one of the Ten Best Products of 1995.

12) JDK 1.0 released in(January 23, 1996).

JAVA CONCEPTS AND TECHNOLOGIES TO DEVELOP ALL APPLICATIONS IN PROJECT

JAVA CONCEPTS AND TECHNOLOGIES TO DEVELOP ANY APPLICATION IN PROJECT

                        Sun Microsystems divided java into three categories to suport all three types of domains mobile, desktop and internet applications. In java a each category is specified as edition. So we can say java concepts are divided into 3 editions they are

1. Java ME (Micro Edition)
2. Java SE (Standard  Edition)
3. Java EE (Enterprise Edition)
                     

for users convinience software industry devided java concepts into 4 divisions 

1. CoreJava
2. Adv java
3. J2EE
   
4. Framework

Frameworks:

                         Frameworks are not part of java SE or Java EE they are developed by third party companies by using Java EE technologies. Frameworks are not developed by SUN/Oracle. Framework softwares are reusable projects used for developing new projects.

Explanation of applications used in Gmail Server Architecture

Explanation of applications used in Gmail Server Architecture 

Conclusions from the above diagram 

Every real worls project contains below three application

• Web supprtive application 
• Web application
• Data interaction application

In JAVA we develop above applications using

• HTML/Applet- to develop web supportive application
•  Servlet and JSP- to develop web application.
• JDBC and EJB- to develop database applications 

In .NET we develop above applications using

• HTML- to develop web supportive application
• ASP.NET         - to develop web application.
• ADO.NET       - to develop database applications 

Web supportive application(HTML/APPLET) is used

•  for collecting input from end user by providing GUI then to pass it to web application
• for displaying output to end user by providing report                  

Web application (servlet and jsp technologies ) is used for

• Processing request and 
• Preparing response 

Server role is processing request means 

1. Reading input from network that is sent by end user via html forms, then
2. Executing business logic by using this input then
3. Finally generating output and sending it to JSP 

JSP role is preparing response means

• Generating dynamic HTML by using the output given by Servlet
• Sending the result HTML back to servlet

Then servlet sends this response to browser to display this output to end user.

1. Database Interaction Application (JDBC/EJB technologies) is used for performing CRUD operation on DB                                                                                                                               DB terminology                                                                                                                            C-       create (insert)R-        read(select)
   U-        update(update)
   D-        delete (deletes)

GMAIL SERVER ARCHITECHTURE

GMAIL SERVER ARCHITECHTURE TO UNDERSTAND BOTH CLIENT SYSTEM BROWSER AND SERVER SYSTEM

Let us understand the gmail server architecture in 12 steps of description

1. First you will open browser, then you enter gmail server address "gmail.com" in the address bar 
2. Soon you press "enter" key on keyboard, you will observe gmail login page is apeared. Is that logic page HTML code available in your computer? Or is it downloaded from gmail server? It is downloaded from general server then your browser renders that html code and displays it to you. now tell me HTML technology develops what type of application? Web supportive application 
3. Now, as per next step you will enter your gmail account username and password, and you will click "sign in" button. If the given username and password is correct you will get your inbox mails, else you will get an error page saying that username and password incorrect.
4. what happened in background? :    Browser sends the given username and password to gmail server. Gmail server reads these values and passes those values to an application runing on server side. It is nothing but servlet, means web application. 
5. Then servlet passes those values to database interaction application, JDBC program.
6. Now, JDBC program executes SELECT query on DB LOGIN table to check whether user exists with the given values or not. If user exists DB returns userid                                                The query would be                                                                                                                   SELECT userid FROM login WhERE uname=givenusername AND pwd=given
7. Using this returned userid, JDBC program executes another SELECT query on INBOX table to get all mails related to this user. DB sends all mails related to this user to JDBC application. The query would be                                                                                                                          SELECT mails FROM inbox WHERE userid= returnedid;
8. Then JDBC application sends those mails to Servlet.
9. Now the servlet sends those mails to jsp to format the mails with help of html hyperlinks 
10. Using these mails, JSP generates HTML code dynamically and sends that html code to servlet 
11. Servlet sends those mails which are formatted in html code to the browser 
12. Finally, the browser displays those mails to user.

FEATURES OF JAVA

To support java as internet application it has following features

• Architecture neutral 
• Byte code
• Compiled and highly interpreted
• Dynamic
• Distributed
• arbage collection
• High performance
• Multithreaded
• Networked
• Object oriented
• Portable
• Robust
• Simple:  
• Secure 
• Platform independent

Is their any abbrevation for java?

 NO JAVA  doesn't have any abbreviation. The development team of java has just choose it. The name java specifically doesn't have any meaning rather it refers to the hot, aromatic drink cofee. This is reason why java icon is cofee cup

Who developed java?

           James Gosling, PHD (born may 19, 1955 near calgary,alberta, canada) along with other engineer scientists discovered Java at SUN Microsystem. He is a famous software developer, best known as the father of java 

Notes for web Supportive application and web application

Web supportive application:


       An application that resides in server system and that is downloaded and executed in client computer via network call is called web supportive application.

                                                Execution control flow diagram 

                                                 

WEB APPLICATION:

                             An application that resides in server system and that is executed directly in the server system via network call and sending response back to client is called web application.

For further explanation please comment

TYPES OF APPLICATIONS

Types of applications 
                               Based on the way of execution of programs, all available applications are divided into 2 types

Stand alone application: 
                           An application that can only be executed in local system with local call is called as stand alone application

Internet application:
                           An application that can be executed in local system with local call and also from remote computer via network call is called internet application.

Types of internet applications:
                          We have two types of internet applications in turn

• Web Supportive Applications            -       executed in client computer
• Web application                                 -       executed in server computer

INTRODUCTION OF JAVA

Why is java???

                                    

                 Java programming language is mainly designed to develop internet applications by providing platform independency. C, c++ programming languages supports developing only stand alone applications, it can only be executed in current system, cannot be executed from remote system via network call.

Then What is java?
         
 Defination: Java is a very simple, high level, secured, multithreaded, platform independent, object oriented programming language.

yeah..... i wish u are fed off with this same old theory oriented definations. But try something new compare your programming skills with our life
object oriented doesnt mean a simple defination. Java is one of programming language that u are going to implement it further in real life projects.
then why dont you start it while studying???????

follow me for further and i will post you the best ever real programing codes