Java Features Lecture 1

Java Features

• Java emerged in 1995 as a response to the growth of the Internet and World-Wide Web, catering to the need for software that can run on different platforms like Windows, Linux, and Solaris.

Design Goals of Java

• Java aimed to address the limitations of languages like C and C++, which had compiled, no robust memory model, no garbage collector, and limited support of built-in libraries.

Java Buzzwords

• Java is described as a simple, object-oriented, distributed, interpreted, robust, secure, architecture-neutral, portable, high-performance, multithreaded, and dynamic language.

Java Language and Libraries

• Java consists of two parts: the core language (variables, arrays, objects) and the libraries (standard library classes that provide "off the shelf" code).
• The Java Virtual Machine (JVM) runs the core language.
• The core language is simple enough to run on small devices like phones, smart cards, and PDAs.
• Java libraries include useful built-in classes like String, ArrayList, HashMap, StringTokenizer, and Date.

Simple

• Java has a similar syntax to C/C++, but is simpler with no operator overloading, no pointers, and no multiple inheritance.
• Java's memory management is simpler than C or C++.

Object-Oriented

• Java is fundamentally based on object-oriented programming (OOP) notions of classes and objects.
• Java uses a formal OOP type system that must be obeyed at compile-time and run-time.

Distributed/Network Oriented

• Java is network-friendly due to its portable, threaded nature, and built-in networking operations in the Java libraries.

Robust/Secure/Safe

• Java is robust, secure, and safe, with features like:
  • Verification of code structure by the JVM "verifier" to prevent unintentional errors and malicious code.
  • Dynamic checking at runtime for pointer and array access to prevent memory errors.
  • Prevention of common bugs and security problems like buffer overflow.
  • Easier debugging due to runtime checks that catch errors.

Introduction to Java language features, covering design goals and platform independence.