![Hello Program Explanation public class HelloProgram { public static void main(String args[]) { String name = “Infoviaan”; System.out.println(“Hello This is ”+name); } } public, class, static, and void are keywords, Keywords are always written in small letters in java. Class Name Keyword Method Variable Object reference 30 www.infoviaan.com](https://image.slidesharecdn.com/java1-introhelloprogram-200311181841/75/JAVA-INTRODUCTION-1-30-2048.jpg)
![Program Explanation Cont. public – Access modifier, shows accessibility of a class or variable or method to other java classes. class - used to define a class. static - is used to assigned memory once in life. void - is null return type of main method. String name = “Infoviaan”; is variable that store a value. System.out.println(“Hello This is ”+ name); is method, which display “Hello This is Infoviaan” at console output. here + is used for concatenate string. main – method is the entry point of program execution. it means program execution start from here. String args[] – Command line arguments 31 www.infoviaan.com](https://image.slidesharecdn.com/java1-introhelloprogram-200311181841/75/JAVA-INTRODUCTION-1-31-2048.jpg)
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JAVA INTRODUCTION - 1
Java is an object-oriented programming language that is high-level, robust, secure, portable and multi-threaded. It was developed by James Gosling at Sun Microsystems in the early 1990s. Java code is compiled into bytecode that runs on a Java Virtual Machine (JVM) making Java platform independent. The JVM interprets the bytecode and performs tasks like memory management and security.
JAVA INTRODUCTION - 1
- 1. Programming in Java www.infoviaan.com JavaIntroduction, Java Features, Hello Program 1
- 2. Java Language Java isHigh level, Object Oriented Programming Language • Object Oriented – Follows OOP methodologies • Java developed by James Gosling and colleagues at Sun Microsystems in the early 1990s. • The acquisition of Sun Microsystems by Oracle Corporation was completed on January 27, 2010 www.infoviaan.com 2
- 3. Programming Language Programming Language- • A programming language is a formal language, which comprises a set of instructions used to produce various kinds of output. • Programming languages are used to create programs or software that implement specific algorithms. • The term programming language usually refers to high-level languages, such as C, C++, Java, Python etc. www.infoviaan.com 3
- 4. High Level Language HighLevel Programming language – • A high-level language that enables development of a program in a much more user-friendly programming context and is generally independent of the computer's hardware architecture. www.infoviaan.com 4
- 5. Java Version History 1997JAVA 1.1 2004 JAVA 5 2011 JAVA 7 No Major Changes between 1.1 to 1.4 Major Changes in 1.5 No Major Changes in Java 6 Major Changes in Java 7 PureOOP 2014 JAVA 8 2017 JAVA 9 2018 JAVA 10 Major Changes Major Changes Major Changes OOP+Functional 5 www.infoviaan.com
- 6. OOP VS FunctionalProg. OOP • Its based on the concept of "objects", which may contain data, in the form of fields, often known as attributes. • It’s code, in the form of procedures, often known as methods. • Class, Object, Encapsulation, Inheritance, Polymorphism, Abstraction etc. are the concepts of OOP. • Ex. Java, Ruby etc. FP • Its try to bind everything in pure mathematical functions style. • It is a declarative type of programming style • Its main focus is on “what to solve” in contrast to an imperative style where the main focus is “how to solve” • Functions, recursion etc. are concept of FP • Ex. C, PHP etc. 6 www.infoviaan.com
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- 8. 1. Object Oriented •Employee in IT company works on multiple Technologies, communicates with each other, works on 2 projects parallel, holds various responsibilities and perform actions/work as per their assigned role. CEO, CTO , CIO , Manager, Team Leader, Developer, Tester, Designer etc. • Object Oriented - • Java follows OOP methodologies. • Focus on the data hold/ associated by objects and methods for manipulating the data. IT Company CIO Manager Team 8 www.infoviaan.com
- 9. Object • Object isrepresents any real world entity • Object actually exists in memory • Objects have states and behaviours. Example: A dog has states - colour, name, breed as well as behaviours – wagging the tail, barking, eating. • Which have own memory • It is Instance of the class University Principal Classroom Computer Lab 9 www.infoviaan.com
- 10. Object has stateand behavior Object has state and behavior State - state are stored in memory variable - state will be changed by behavior Behavior- behavior perform operation - behavior are implemented by function, and function are called method in OOP. States/variables Colour: white Gear: 2nd Speed: 40 Behaviour/method changeColor() changeGear() accelerator() break() Object 10 www.infoviaan.com
- 11. Structure of anobject Before any object creation you have to create structure or design. • Structure means template or blueprint of an object. • Class is the structure or skeleton or design of an object. • State and behavior of an object are defined by Class. • Object is the instance/memory of the class. State / Member Variable/ Attribute Function / Method / Member method Class 11 www.infoviaan.com
- 12. Class vs Object Hall WashroomBedRoom Bed Room Wash basin path Gate Kitchen Plot – Map (blueprint) Class Constructed – Object 1 Constructed – Object 2 State/Attributes : door window color Behaviour/Method: changeColor() changeDoor() openWindow() … Washroom Washroom 12 www.infoviaan.com
- 13. 2. Simple • Javais easy to write and more readable. • Java has a concise, cohesive set of features that makes it easy to learn it easy to learn and use. • No pointers • Automatic garbage collection (memory management). • Java was designed to make it much easier to write bug free code. • Java is an excellent teaching language, and an excellent choice with which to learn programming. The language is small so it's easy to become fluent. 13 www.infoviaan.com
- 14. 3. Secured Java issecured because: • No explicit pointer • Java programs run inside virtual machine sandbox C/C++ application Operating System Uses runtime Environment of its own Java Virtual Machine Uses runtime environment Of OS Java application Operating System Uses runtime environment Of OS 14 www.infoviaan.com
- 15. 4. Platform Independent Hardware Software OS:windows/Linux/Sun Solaris CPU/Mother Board/RAM Platform What is Platform? 15 www.infoviaan.com
- 16. Machine Developer machine Client machine Develop + Run Compiler(javac) +Interpreter(JRE/JVM) JDK JDKVS JRE Only Run Interpreter(JRE/JVM) JRE 16 www.infoviaan.com
- 17. Turbo C++ Compiler A.cpp Machine Code A.java Javac Compiler JRE/JVM Byte Code C/C++: Platform Dependent Java: Platform Independent Platform dependable A.obj A.class Platform Independent Cont. Software Hardware Platform 17 www.infoviaan.com Software Hardware Platform
- 18. C, C++ Windows LinuxMac OS .C .obj/ machine code Windows Linux .C machine code Mac OS Development Machine Run Machine .C machine code 18 www.infoviaan.com
- 19. Class File Windows LinuxMac OS Windows JavaDevelopment Machine RunMachine Windows JVM/Setup Linux JVM/Setup Mac/OS JVM/Setup 19 www.infoviaan.com
- 20. JDK JDK, JRE andJVM .javac JRE JVM .javaw bytecode / .class 20 www.infoviaan.com
- 21. 5. Robust Robust meansstrong. Java program are strong and they don’t crash easily like c and c++. • Excellent exception handling • Memory management • Class loader sub system of JVM will allocate necessary memory for java program. • Garbage collector de allocates the memory. 21 www.infoviaan.com
- 22. 6. Portable • Javais considered as Portable because – Output of a Java compiler is Non Executable Code i.e Bytecode. Bytecode is executed by Java run-time system, which is called the Java Virtual Machine (JVM). • They can run on any platform without being re compiled. • Being architectural-neutral and having no implementation dependent aspect of the specification makes java portable. Machine 1 - Window Machine 2 - Linux Connected with LANHello.class Hello O/P 22 www.infoviaan.com
- 23. 7. Architectural-neutral • Writeonce, run anywhere (WORA) • With a JVM, you can write one program that will run on any platform. • Java compiler generates an architectural-neutral object file format, which makes the compiled code executable on many processors, with the presence of Java Runtime System. • Means java byte code is architectural-neutral . 23 www.infoviaan.com
- 24. 8. Dynamic • Javais dynamic because, java bytecode(.class file) is interpreted by JVM. • Static means, java source code (.java file) is compiled into another language(byte code) before it is executed – it is not directly executable. • So , we might say that java byte code is dynamic. • Java has Dynamic and Extensible Code Means With the Help of OOPS java Provides Inheritance and With the Help of Inheritance we Reuse the Code that is Pre-defined and Also uses all the built in Functions of java and Classes 24 www.infoviaan.com
- 25. 9. Compile &Interpreted Compiler – • Convert complete source code at a time of a program. • Fast Processing. • Worked Before run of program Converting source code to byte code in one shot Converting source code to byte code line by line JAVAC JIT Interpreter – • Convert source code Line by line of a program. • Slow Processing. • Worked after run of program 25 www.infoviaan.com
- 26. 10. High Performance •Java performance is improved in newer “Just-in- time(JIT)” JVM’s , which compile methods after some number of executions, and save machine code to give compiled-code efficiently thereafter. • Java performance is impressive for an interpreted language. • Due to the use of intermediate byte code. • Java architecture is also designed to reduce overheads during runtime. 26 www.infoviaan.com
- 27. 11. Multithreaded • Javasupports multithreaded programming, which allows you to write programs that do many things simultaneously. • The Java run-time system contains tools to support multiprocess synchronization and construct smoothly running interactive systems. Multitasking – Multiple work run simultaneously Multithreading – One process contains multiple sub process/lightweight processes. 27 www.infoviaan.com
- 28. 12. Distributed • Javais Distributed Language Means because the program of java is compiled onto one machine can be easily transferred to machine and Executes them on another machine because facility of Bytes Codes So java is Specially designed For Internet Users which uses the Remote Computers. • Java provides an extensive library of classes for communicating ,using TCP/IP protocols such as HTTP and FTP. • This makes creating network connections much easier than in C/C++. • You can read and write objects on the remote sites via URL with the same ease that programmers are used to when read and write data from and to a file. • This helps the programmers at remote locations to work together on the same project. 28 www.infoviaan.com
- 29. Java Installation Step 1:Download JDK. • Go to - https://www.oracle.com/technetwork/java/javase/downloads/index.ht ml Step 2: Install JDK and JRE. • Run - jdk-8u181-windows-i586.exe (version can be different) Step 3: Include JDK's "bin" Directory in the PATH. • Launch "Control Panel" ⇒ (Optional) System and Security ⇒ System ⇒ Click "Advanced system settings" on the left pane. • Switch to "Advanced" tab ⇒ Push "Environment Variables" button. • Under "System Variables" (the bottom pane), scroll down to select "Path" ⇒ Click "Edit.". Step 4: Verify the JDK Installation. • Go to Command prompt and check verify. Step 5: Write a Hello-World Java Program. Step 6: Compile and Run the Hello-World Java Program. 29 www.infoviaan.com
- 30. Hello Program Explanation publicclass HelloProgram { public static void main(String args[]) { String name = “Infoviaan”; System.out.println(“Hello This is ”+name); } } public, class, static, and void are keywords, Keywords are always written in small letters in java. Class Name Keyword Method Variable Object reference 30 www.infoviaan.com
- 31. Program Explanation Cont. public– Access modifier, shows accessibility of a class or variable or method to other java classes. class - used to define a class. static - is used to assigned memory once in life. void - is null return type of main method. String name = “Infoviaan”; is variable that store a value. System.out.println(“Hello This is ”+ name); is method, which display “Hello This is Infoviaan” at console output. here + is used for concatenate string. main – method is the entry point of program execution. it means program execution start from here. String args[] – Command line arguments 31 www.infoviaan.com
- 32. Process to runjava program javac Hello.java java Hello Hello World Compile Run .main() 32 www.infoviaan.com
- 33. A.java Javac (Compiler) A.class JVM(Interpreter) Final Output 1)Byte Code Verifier 2) Class Loader 3) JIT(Just In Time Compiler) 4) Execution Engine 5) Garbage Collector Byte Code Machine Code Working Process 33 www.infoviaan.com
- 34. Java Uses 1. J2SE: - Desktop GUI Applications: Java provides GUI development through various means like Abstract Windowing Toolkit (AWT), Swing and JavaFX. (Used to develop Stand Alone/Desktop based applications) 2. Mobile Applications: - Android applications can be developed by using the Java programming language 3. Embedded Systems: - It is a combination of hardware and software that is designed for specific tasks, providing a function and embedded within a larger electrical system 4. J2EE : - Building and deploying Web-based enterprise applications. 5. Scientific Applications 34 www.infoviaan.com
- 35. Questions 1. Why Javais Platform Independent? 2. JDK vs JRE 3. What name of java compiler and Interpreter? 4. Is Java compiler produce machine code? 5. Is Java produce machine code? 6. What is Byte code? 7. Is JVM is Platform Independent or not? 8. Components of JVM 9. Why it is called Virtual machine? 10. Types of Virtual Machine. 11. Types of Java applications 35 www.infoviaan.com
- 36. Get in Touch ThankYou www.infoviaan.com 36 www.infoviaan.com