Java
- 2. INTRODUCTION
- 3. What is java? Developed by Sun Microsystems (James Gosling) A general-purpose object-oriented language Based on C/C++ Designed for easy Web/Internet applications Now developing by Oracle
- 4. JAVA - AN INTRODUCTION • Java - The new programming language developed by Sun Microsystems in 1991. • Originally called Oak by James Gosling, one of the inventors of the Java Language. • Java -The name that survived a patent search • Java Authors: James , Arthur Van , and others • Java is really “C++ -- ++ “
- 5. JAVA INTRODUCTION • Originally created for consumer electronics (TV, VCR, Freeze, Washing Machine, Mobile Phone). • Java - CPU Independent language • Internet and Web was just emerging, so Sun turned it into a language of Internet Programming. • It allows you to publish a webpage with Java code in it.
- 6. JAVA FEATURES • Simple • fixes some clumsy features of C++ • no pointers • automatic garbage collection • rich pre-defined class library http://java.sun.com/j2se/1.4.2/docs/api/ • Object oriented • focus on the data (objects) and methods manipulating the data • all functions are associated with objects • almost all datatypes are objects (files, strings, etc.) • potentially better code organization and reuse
- 7. JAVA FEATURES • Interpreted • java compiler generate byte-codes, not native machine code • the compiled byte-codes are platform-independent • java bytecodes are translated on the fly to machine readable instructions in runtime (Java Virtual Machine) • Portable • same application runs on all platforms • the sizes of the primitive data types are always the same • the libraries define portable interfaces
- 8. JAVA FEATURES • Reliable • extensive compile-time and runtime error checking • no pointers but real arrays. Memory corruptions or unauthorized memory accesses are impossible • automatic garbage collection tracks objects usage over time • Secure • usage in networked environments requires more security • memory allocation model is a major defense • access restrictions are forced (private, public)
- 9. JAVA FEATURES • Multithreaded • multiple concurrent threads of executions can run simultaneously • utilizes a sophisticated set of synchronization primitives (based on monitors and condition variables paradigm) to achieve this • Dynamic • java is designed to adapt to evolving environment • libraries can freely add new methods and instance variables without any effect on their clients • can check the class type in runtime