JAVA Programming-Lectures-1_javaFeatures (2).docx
- 1. Introduction of JAVA: JAVA was developed by James Gosling at Sun Microsystems Inc in the year 1995, later acquired by Oracle Corporation. Java is a programming language and a platform. Java is a high level, robust, object- oriented and secure programming language. Application of JAVA: 1. Desktop Applications such as acrobat reader, media player, antivirus, etc. 2. Web Applications such as irctc.co.in, javatpoint.com, etc. 3. Enterprise Applications such as banking applications. 4. Mobile 5. Embedded System 6. Smart Card 7. Robotics 8. Games, etc. Features of JAVA: 1)Simple: Java is very simple & easy to learn. We can write java programs very easily. To learn java no prior knowledge is required. Most of the common complex & confusing features of other languages (C, C++) like pointers, multiple inheritance, etc. removed from java. 2)Platform Independent: If we write java program once, we can run on any platform. i.e. java follows Write Once Run Anywhere principle(WORA). We can run same java program on Windows, Linux & MAC also.
- 2. Fig. platform Independent 3)Architecture Neutral: Java programs never communicates with the platform directly. Changes & upgrades in Operating Systems, processors and system resources will not force any changes of java programs. 4)Portable: We can carry the java byte code to any platform without making any changes. Mobile number portability in India from Airtel to Jio, for that no need to change number, same byte code (class file) can run on any platform. 5)Secure: Java program never communicates directly with the machine. First converted into byte code and then converted into machine code by the jvm. If the bytecode contains any problem or if it is not properly formatted, then JVM won’t allow that code to run & will raise Verify Error. Internally inside JVM, Bytecode verifier is responsible to verify byte code. Hence, java programs won’t cause any problem to the system. 6)Object Oriented Programming Language:
- 3. Java is object oriented programming languages like C++, most of the times in java, we have to handle everything in terms of object. Java provide support for the following OOP features: Inheritance, Polymorphism, Encapsulation, Association, Abstraction, class & Objects. 7)Multithreaded: In the case of multithreading, multiple threads can run simultaneously and can perform specified task simultaneously, so that performance of the application will be improved. Java provides inbuilt support for multithreading by providing a rich API. Java won’t parallelize code execution automatically. It provides Libraries, By using those we have to write code for parallel execution. 8)Robust: Java is strongly typed language. Compiler will check each & every declaration & assignments at compile time only for type compatibility. If any problem w.r.t. types, then at compile time only we can identify the problem. It provides garbage collector for automatic memory management. Hence, there is no chance of memory related problems. Java provides inbuilt Exception Handling. Which prevents abnormal termination of the program at runtime. Java is platform independent and it can run on any platform. Because of all these facilities, the chance of failing the program at runtime is very less and hence, java is Robust. 9)Distributed: If the application is distributed across multiple machines(JVMs) such type of application is called Distributed application. Java provides inbuilt support for distributed programming with RMI (Remote method Invocation). 10)Compiled & interpreted: Java is both Compiled & Interpreted Programming language. First java compiler compiles java code and generates machine independent Byte code. At runtime JVM interprets this byte code into machine code and executes that machine code.
- 4. Fig. Java is compiled & interpreted 11)High Performance: Java is relatively faster than traditional interpreted languages, since the byte code is close to native code. It provides high performance due to JIT compiler. Because it has more information available. 12) Dynamic: In the case of java programs, all .class files won’t be loaded at the beginning. At runtime if JVM required any class then only the corresponding .class file will be loaded (Dynamic loading). The main advantage is program will always get latest version of .class file and memory utilization will be improved.