1. Java Programming, 2E Introductory Concepts and Techniques Chapter 1 An Introduction to Java and Program Design

2. Chapter 1: An Introduction to Java and Program Design 2 Object-Oriented Programming Data and the operations on the data are packaged into a unit An interface of properties and functions is exposed to the outside world

3. Chapter 1: An Introduction to Java and Program Design 3 Classes Specifications of data and operations Class rectangle { int length; int width; int size(); int perimeter(); }

4. Chapter 1: An Introduction to Java and Program Design 4 Objects An object is an instance of a class A real entity that exists in the system –Take up a block of memory Many objects of the same class can exist at the same time Two rectangle objects: rect1, rect2 rect1.length != rect2.length rect1.width != rect2.width rect1.size() != rect2.size()

5. Chapter 1: An Introduction to Java and Program Design 5 Java Designed and developed by Sun Microsystems in the early 1990’s One of the most widely used object- oriented programming languages

6. Chapter 1: An Introduction to Java and Program Design 6 Characteristics of Java Portable –Platform-independent –“write once, use everywhere” Secure –Protection against misuse of code Robust –Strongly typed and incorruptible data

7. Chapter 1: An Introduction to Java and Program Design 7 Java Program Types Console and Windowed applications Applets Servlets Web Services JavaBeans

8. Chapter 1: An Introduction to Java and Program Design 8 Console Applications Stand-alone programs using a command- line interface

9. Chapter 1: An Introduction to Java and Program Design 9 Windowed Applications Stand-alone programs using a graphical user interface (GUI)

10. Chapter 1: An Introduction to Java and Program Design 10 Applets Client-side programs executed within a Web browser

11. Chapter 1: An Introduction to Java and Program Design 11 Servlets Server-side programs hosted and run on a Web server Used in conjunction with Java Server Pages (JSP) to provide sophisticated server-side logic Enable connections to databases through Java Database Connectivity (JDBC)

12. Chapter 1: An Introduction to Java and Program Design 12 Servlets

13. Chapter 1: An Introduction to Java and Program Design 13 Web Services Services receive information requests over the Web and return the requested data

14. Chapter 1: An Introduction to Java and Program Design 14 JavaBeans Reusable software components

15. Chapter 1: An Introduction to Java and Program Design 15 Java Program Development Using J2SE The Java Compiler –Converts code into bytecode The Java Virtual Machine –Contains an interpreter to execute the bytecode The Java API –The standard set of packages available in Java The Java Applet Viewer –Mini browser to display Java applets

16. Chapter 1: An Introduction to Java and Program Design 16 Java Program Development Using J2SE The Java Compiler –Converts code into bytecode The Java Virtual Machine –Contains an interpreter to execute the bytecode The Java API –The standard set of packages available in Java The Java Applet Viewer –Mini browser to display Java applets Enter Java source code using any text-editor

17. Chapter 1: An Introduction to Java and Program Design 17 Summary Classes & Objects Characteristics of Java Java program types Java program development

18. Chapter 1: An Introduction to Java and Program Design 18 For Your Interests Java Technology: The Early Years