Unit 2: What is Database?

What is Database?



A Database is a collection of related data organized in a way that data can be easily accessed, managed and updated.
In a database, we would be grouping only related data together and storing them under one group name called table.



For example below:
_Library catalogues 
_Medical records 
_Bank accounts 
_Product catalogues 
_Telephone directories 
_Train timetables 
_Airline bookings 
_Credit card details 
_Student records 
_Discussion boards and so on…

Databases are useful because: 
Many computing applications deal with large amounts of information 
Database systems give a set of tools for storing, searching and managing this information

Database systems are systems in which the interpretation and storage of information are of primary importance.
It is a system that allows users to Store, Update, Retrieve, Organize, and Protect their data. 

Unit 1: What is Data and Information?

What is Data and Information?



What is Data?
Data, is defined as a body of facts or figures, which have been gathered for one or more specific purposes
data can exist in the forms of
linguistic expressions (e.g. name, age, address, date, ownership)
symbolic expressions (e.g. traffic signs)
mathematical expressions (e.g. E = mc2)
signals (e.g. electromagnetic waves)

What is Information?
Information, is defined as data which have been processed into a form that is meaningful to a recipient. In other words, data has to be interpreted in order to obtain information.
- although data are ingredients of information, not all data make useful information
- information is only useful to its recipients when it is
    +  relevant (to its intended purposes and with appropriate level of required detail)
    +  reliable, accurate and verifiable (by independent means)
    +  up-to-date and timely (depending on purposes)
Information system, is  a system used to  change "data" into "information“.

Unit 4: What are all the features of Java Programming Languages? Features Contd....

Features Contd....

- Robust:
    Robust simply means strong. Java uses strong memory management. There is lack of           pointers that avoids a security problem. There is automatic garbage collection in java. There     are exception handling and type checking mechanism in java. All these points make java         robust.

- Architectural-neutral:
   There is no implementation dependent features e.g. size of primitive types is set.

- Portable
   We may carry the java bytecode to any platform.

- High – Performance
   Java is faster than traditional interpretation since bytecode is "close" to native code still        somewhat slower than a compiled language (e.g., C++)

- Distributed
   We can create distributed applications in java. RMI and EJB are used for creating                    distributed applications. We may access files by calling the methods from any machine on      the internet.

- Multi-Threaded

   A thread is a separate program, executing concurrently. We can write Java programs        that deal with many tasks at once by defining multiple threads. The main advantage of            multi-threading is that it shares the same memory. Threads are important for multi-                media, Web applications etc.

Unit 4: What are all the features of Java Programming Languages? Features Contd....

Features Contd....



- Platform Independent:
A platform is the hardware or software environment in which a program runs.                           There are two types of platforms software-based and hardware-based. Java                         provides the software-based platform. The Java platform differs from most other                         platforms in the sense that it's a software-based platform that runs on top of other                   hardware-based platforms.It has two components:
1. Runtime Environment,   2. API(Application Programming Interface)

- Java is secured because:
No explicit pointer
Programs run inside virtual machine sandbox

       

Unit 4: What are all the features of Java Programming Languages?

What are all the features of Java Programming Languages?

The Features of Java
- Simple
- Object-Oriented
- Platform independent
- Secured
- Robust
- Architecture neutral
- Portable
- Dynamic
- Interpreted
- High Performance
- Multithreaded
- Distributed

The Details of Each Features
1_Simple
According to Sun, Java language is simple because:
 + the syntax is based on C++ (so easier for programmers to learn it after C++).
 + removed much confusing and/or rarely-used features e.g., explicit pointers, operator overloading etc.
 + No need to remove unreferenced objects because there is Automatic Garbage Collection in java.

2_Object-oriented
 + Object-oriented means we organize our software as a combination of different types of objects that incorporate both data and behavior.
 + Object-oriented programming(OOPs) is a methodology that simplifies software development and maintenance by providing some rules.
 + Basic concepts of OOPs are: 
      Object
      Class
      Inheritance
      Polymorphism
      Abstraction
      Encapsulation.

Continued....

Unit 3: The history of Java Programming

The history of Java Programming

- James Gosling, Mike Sheridan, and Patrick Naughton initiated the Java language project in June 1991. The small team of sun engineers called Green Team.
- Originally designed for small, embedded systems in electronic appliances like set-top boxes.
 - Firstly, it was called "Greentalk" by James Gosling and file extension was .gt.
- After that, it was called Oak and was developed as a part of the Green project.
- Why Oak? Oak is a symbol of strength and chosen as a national tree of many countries like U.S.A., France, Germany, Romania etc.
- In 1995, Oak was renamed as "Java" because it was already a trademark of Oak Technologies.
- Why they chose java name for java language?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.
- Java is an island of Indonesia where first coffee was produced (called java coffee).
- Notice that Java is just a name, not an acronym.
- Originally developed by James Gosling at Sun Microsystems (which is now a subsidiary of Oracle Corporation) and released in 1995.
- In 1995, Time magazine called Java one of the Ten Best Products of 1995.
- JDK 1.0 released in(January 23, 1996).

Java Programming Version History
There are many java versions that have been released. Current stable release of Java is Java SE 8.
- JDK Alpha and Beta (1995)
- JDK 1.0 (23rd Jan, 1996)
- JDK 1.1 (19th Feb, 1997)
- J2SE 1.2 (8th Dec, 1998)
- J2SE 1.3 (8th May, 2000)
- J2SE 1.4 (6th Feb, 2002)
- J2SE 5.0 (30th Sep, 2004)
- Java SE 6 (11th Dec, 2006)
- Java SE 7 (28th July, 2011)
- Java SE 8 (18th March, 2014)

Unit 2: What are the types of Java Applications?

What are the types of Java Applications?

There is mainly 4 type of applications that can be created using java programming:

1_Standalone Application :

         It is also known as the desktop application or window-based application. An application that we need to install on every machine such as media player, antivirus etc. AWT and Swing are used in java for creating standalone applications.

2_Web Application :

          An application that runs on the server side and creates the dynamic page, is called web application. Currently, servlet, JSP, struts, JSF etc. technologies are used for creating web applications in java.

3_Enterprise Application :

          An application that is distributed in nature, such as banking applications etc. It has the advantage of the high-level security, load balancing, and clustering. In java, EJB is used for creating enterprise applications

4_Mobile Application

          An application that is created for mobile devices. Currently, Android and Java ME are used for creating mobile applications.

Unit 1: What is Java, where did it used?

What is Java, where it used?

What is Java?
Java is a programming language and a platform
Java is a high level, robust, secured and object-oriented programming language
Platform : Any hardware or software environment in which a program runs, is known as a platform. Since Java has its own runtime environment (JRE) and API, it is called platform

Where did it use ?
According to Sun, 3 billion devices run java. There are many devices where java is currently used. Some of them are as follows:
- Desktop Applications such as acrobat reader, media player, antivirus etc.
- Web Applications such as irctc.co.in  etc.
- Enterprise Applications such as banking applications.
- Mobile
- Embedded System
- Smart Card
- Robotics
- Games etc.