Introduction to Java Programming PDF

Week – 1 Tutorial Introduction JAVA | 2 Java (Programming Language) Java is a object oriented programming language. It was first developed by James Gosling at Sun Microsystems, which is now a part of Oracle Corporation. | 3...

Week – 1 Tutorial Introduction JAVA | 2 Java (Programming Language) Java is a object oriented programming language. It was first developed by James Gosling at Sun Microsystems, which is now a part of Oracle Corporation. | 3 Java (Programming Language) It was released in 1995 as a part of Sun Microsystems Java platform. Note: Java is an island of Indonesia where first coffee was produced (called javacoffee) | 4 Features of Java | 5 Features of Java Simple:- -syntax is based on C++ (so easier for programmers to learn it after C++). -removed many confusing and/or rarely-used features e.g., explicit pointers, operator overloading etc. -No need to remove unreferenced objects because there is Automatic Garbage Collection in java. Object-oriented:- -Object-oriented means we organize our software as a combination of different types of objects that incorporates both data and behavior. -Object-oriented programming(OOPs) is a methodology that simplify software development and maintenance by providing some rules. Basic concepts of OOPs are: 1. Object 2. Class 3. Inheritance 4. Polymorphism 5. Abstraction 6. Encapsulation | 6 Features of Java Platform Independent:- -Java code can be run on multiple platforms e.g. Windows, Linux, Sun Solaris, Mac/OS etc. -Java code is compiled by the compiler and converted into bytecode. -This bytecode is a platform-independent code because it can be run on multiple platforms i.e. Write Once and Run Anywhere(WORA). | 7 Features of Java Secured: Java is secured because: -No explicit pointer -Java Programs run inside virtual machine sandbox -Classloader: adds security by separating the package for the classes of the local file system from those that are imported from network sources. -Bytecode Verifier: checks the code fragments for illegal code that can violate access right to objects. -Security Manager: determines what resources a class can access such as reading and writing to the local disk. | 8 Features of Java Robust: -Java uses strong memory management. -There are lack of pointers that avoids security problem. -There is automatic garbage collection in java. -There is exception handling and type checking mechanism in java. Architecture-neutral: -There is no implementation dependent features e.g. size of primitive types is fixed. -In C programming, int data type occupies 2 bytes of memory for 32- bit architecture and 4 bytes of memory for 64-bit architecture. But in java, it occupies 4 bytes of memory for both 32 and 64 bit architectures. Portable: We may carry the java byte code to any platform. | 9 Features of Java High-performance: Java is faster than traditional interpretation since byte code is "close" to native code still somewhat slower than a compiled language (e.g., C++) Distributed: We can create distributed applications in java. RMI and EJB are used for creating distributed applications. We may access files by calling the methods from any machine on the internet. Multi-threaded: -A thread is like a separate program, executing concurrently. -We can write Java programs that deal with many tasks at once by defining multiple threads. -The main advantage of multi-threading is that it doesn't occupy memory for each thread. It shares a common memory area. - Threads are important for multi-media, Web applications etc. | 10 Text Editor - Notepad - Notepad++ - BlueJ - Netbeans - Eclipse | 11 2 steps to execute a JAVA program. a. 1st step is to compile the JAVA program. To compile, we use the command javac. | 12 b. 2nd step is to run the JAVA program. To run the java program, we use the command java. | 13 To perform these 2 steps we need to have JDK(Java Development Kit) installed on your machine. | 14 What is JDK? | 15 JDK Acronym for Java Development Kit JAVA DEVELOPMENT KIT Process of developing | 16 JDK A development environment used to develop Java applications. Contains JRE (Java Runtime Environment) + JVM (Java Virtual Machine) Using JDK, we can develop, create and update existing Java program as well as we can compile and run a Java Program. | 17 JDK JRE IS SUBSET OF __________? JVM is subset of __________? | 18 JRE Acronym for Java Runtime Environment JAVA Runtime Environment Process to run | 19 JRE Provides only environment to run a Java program It does not provides any development tools to develop a new Java program Using JRE, we can only run existing Java program, but we cannot develop a Java program. | 20 JVM Acronym for Java Virtual Machine JAVA Virtual Machine Something which is not real | 21 JVM Responsible to execute a Java Bytecode. Provides Interpreter + Compiler (JIT) | 22 What is a Compiler? Any idea? | 23 Compiler | 24  Interpreter Assembler | 25 Structure of JAVA program package test // package declaration public class Hello { public static void main (String [] args) // main method { System.out.println(“Hello World”); //print out } } | 26 | 27 JAVA Rule and Convention Class name and the file name should have same name. File name should be save in.java extension. (eg: Hello.java) The system must have JDK installed. Locate the C:\Program Files\Java\jdk1.7.0_07\bin in My Computer →Properties → Advanced system settings → Environment Variables → New Variable Name : Path Variable Value : C:\Program Files\Java\jdk1.7.0_07\bin | 28  Open console (command prompt). Locate to Hello.java drive or its specific folder. javac Hello.java java Hello | 29 Any Questions?? | 30