History of Java

History of Java

1. Java is a general purpose object oriented programming  language.

2. Developed by Sun Microsystems. (James Gostling)

3. Initially called “Oak” but was renamed as “Java” in 1995.

4. Initial motivation is to develop a platform independent language to create software to be embedded in various consumer electronics devices.

5. Become the language of internet. (portability and security).

Features of Java

1. Simple, Small and Familiar

2. Compiled and Interpreted

3. Object Oriented

4. Platform Independent and portable

5. Robust and Secure

6. Distributed / Network Oriented

7. Multithreaded and Interactive

8. High Performance

9. Dynamic 

Simple, Small and Familiar

Similar to C/C++ in syntax.

But eliminates several complexities of

No operator overloading.

No direct pointer manipulation or pointer arithmetic.

No multiple inheritance.

No malloc() and free() – handles memory automatically.

Compiled and Interpreted

Java works in two stage.

Java compiler translate the source code into byte code.

Java interpreter converts the byte code into machine level

representation.

Byte Code:

-A highly optimized set of instructions to be executed by tehe java runtime system, known as java virtual machine (JVM).

-Not executable code.

Java Virtual Machine (JVM):

-Need to be implemented for each platform.

-Although the details vary from machine to machine, all JVM understand the same byte code.