Java

1. SRI KRISHNA COLLEGE OF ENGINEERING AND TECHNOLOGY
Kuniamuthur, Coimbatore, Tamilnadu, India
An Autonomous Institution, Affiliated to Anna University,
Accredited by NAAC with “A” Grade & Accredited by NBA (CSE, ECE, IT, MECH ,EEE, CIVIL& MCT)
Course :FUNDAMENTALS OF JAVA PROGRAMMING
Module 1 :JAVA BASICS
Topic : HISTORY OF JAVA,JAVA BUZZWORDS,JVM
Faculty : Dr.RESHMA V.K
Associate Professor/CSE
SKCET
www.skcet.ac.in

2. Objectives
• History of Java
• Java platform overview
• Java ecosystem (JDK- JVM & JRE)
• Application Types
• Naming Conventions
• Java Features
• Benefits of Java

3. 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.Java has
its own runtime environment (JRE) and API.it is called as
platform.

4. History
• James Gosling, Mike Sheridan, and Patrick Naughton
initiated the Java language project in June 1991.
• 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.

5. Where it is used?

6. How JAVA is different from C?

7. How JAVA is different from C++?

8. How JAVA is different from
C++?

9. How JAVA is different from C++?

10. How JAVA is different from C++?

11. •JVM
–Java Interpreter + Just-In-Time Compiler
–JVM (Java Virtual Machine) is an abstract machine. It is a specification that
provides runtime environment in which java byte code can be executed.
–JVMs are available for many hardware and software platforms. It is the code
execution component of the Java platform.
–It is a Runtime Instance Whenever you write java command on the command
prompt to run the java class, an instance of JVM is created.
•Note:
–JVM, JRE and JDK are platform dependent because configuration of each OS
differs. But, Java is platform independent.
JVM ARCHITECTURE

12. JVM
The JVM performs following operation:
• Loads code
• Verifies code
• Executes code
• Provides runtime environment
JVM provides definitions for the:
• Memory area
• Class file format
• Register set
• Garbage-collected heap
• Fatal error reporting etc.

16. JAVA Features
- Simple
- Object-Oriented
- Portable
- Platform Independent
- Secured
- Robust
- Architecture Neutral
- Dynamic
- Interpreted
- High Performance
- Multithreaded
- Distributed
Courtesy : https://www.youtube.com/bardlearning

17. JAVA Features
• Simple
- Syntax is based on C++ (So easier for programmers to
learn it after C++).
- Removed many 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.

18. JAVA Features
Object-Oriented:-
- Object-oriented programming(OOPs) is a methodology
that simplify software development and maintenance by
providing some rules.
Basic concepts of OOPs are:-
- Object
- Class
- Inheritance
- Polymorphism
- Abstraction
- Encapsulation

19. JAVA Features
Platform Independent:-
- Java code can be run on
multiple platforms.
- e.g. Windows, Linux,
Sun Solaris, Mac/OS etc.
- Java code is compiled by the
Compiler and Converted into
bytecode.
- This bytecode is a platform independent
code because it can be run on multiple platforms
- i.e. Write Once and Run Anywhere(WORA).

20. JAVA Features
• Secured
- Java is Secured because:
- No Explicit Pointer
- Java program run inside
Virtual Machine Sandbox
When you run an application inside a sandbox, it continues to have access to everything that it
would were it not sandboxed. The primary difference is that anything created or changed by the
sandboxed application is:
● Not visible outside of the sandbox; other applications don’t see it.
● Not saved when the sandboxed application exits.

21. JAVA Features
• Robust(All Above Points Makes JAVA Robust)
- Robust simply means Strong.
- Java uses strong Memory Management.
- There are Automatic Garbage Collection in JAVA.
-There is Exception Handling and Type Checking Mechanism
in JAVA.
• Architecture-Neutral
- There are No implementation Dependent Features
- e.g. size of primitive types is fixed.
- In C programming, int Data Type occupies 2 Bytes of
Memory for 32-bit Architecture and 4 Bytes of Memory for
64-bit Architecture. But in java, it occupies 4 Bytes of
Memory for Both 32 and 64 bit Architectures.

22. JAVA Features
• Portable:-
- We may carry the JAVA Bytecode to Any Platform.
• High-Performance:-
- Java is faster than traditional interpretation since byte
code is "close" to native code still somewhat slower than a
compiled language (e.g., C++)

23. JAVA Features
• Multithreaded
- A Thread is like 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 doesn't occupy
memory for each thread.
- It shares a Common Memory Area.
- Threads are important for Multi-Media,Web applications etc.
• Distributed
- We can create Distributed Applications in Java.
- RMI(Remote Method Invocation) and EJB(Enterprise JavaBeans)
are used for creating Distributed Applications.
- Can access files by calling the methods from any machine on the
Internet.

24. Summary
• Java Evolution trend
• Java environment and its significance
• Java Features
• Benefits of Java