Outline. Introduction to Java. What Is Java? History. Java 2 Platform. Java 2 Platform Standard Edition. Introduction Java 2 Platform

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1 Outline Introduction to Java Introduction Java 2 Platform CS 3300 Object-Oriented Concepts Introduction to Java 2 What Is Java? History Characteristics of Java History James Gosling at Sun Microsystems Previous called Oak in 1991 for consumer electronic applications Renamed to Java and redesigned for Internet applications in May 1995 HotJava The first Java-enabled Web browser CS 3300 Object-Oriented Concepts Introduction to Java 3 CS 3300 Object-Oriented Concepts Introduction to Java 4 Java 2 Platform Java 2 Platform Standard Java 2 Platform Enterprise Java 2 Platform Micro Java 2 Platform Standard For developing stand-alone applications JVM to execute Java programs Development tools -- compiler, debugger, profiler, and documentation generator Core APIs (Application Program Interfaces) -- core language support, utilities, input and output, networking, preferences collections, security, locale support, logging, Java beans, XML processing, and native interface GUI APIs -- AWT (Abstract Window Toolkit), Swing, 2- dimensional graphics, and sound support Integration APIS remote method invocation (RMI), database connectivity (JDBC), naming and directory services (JNDI) Deployment tools Java Web start and Java plug-in CS 3300 Object-Oriented Concepts Introduction to Java 5 CS 3300 Object-Oriented Concepts Introduction to Java 6 1

Java 2 Platform Enterprise For developing sever applications Java servlets and Java server pages (JSP) Enterprise Java beans (EJB) E-mail and messaging services Transaction management Java 2 Platform

2 Java 2 Platform Enterprise For developing sever applications Java servlets and Java server pages (JSP) Enterprise Java beans (EJB) and messaging services Transaction management Java 2 Platform Standard CS 3300 Object-Oriented Concepts Introduction to Java 7 CS 3300 Object-Oriented Concepts Introduction to Java 8 Java 2 Platform Micro For developing small applications Connected Device Configuration (CDC) for high-end consumer electronic devices Web appliances Connected, Limited Device Configuration (CLCD) for low-end information devices -- PDAs, cellular phones CS 3300 Object-Oriented Concepts Introduction to Java 9 Characteristics of Java Java is simple Automatic memory allocation and garbage collection Java is object-oriented Java is distributed Java is interpreted JVM code -- bytecode Java is robust or reliable Java has a runtime exception-handling feature Java is secure Java is architecture-neutral (platform independent) Java programs can be run on any platform CS 3300 Object-Oriented Concepts Introduction to Java 10 Characteristics of Java Java is portable Java programs can run on any platform without having to be recompiled Java s performance Java is multithreaded Java program is capable of performing several tasks simultaneously within a program Java is dynamic Methods and properties can be added in a class without affecting their clients CS 3300 Object-Oriented Concepts Introduction to Java 11 JDK Versions JDK 1.02 (1995) JDK 1.1 (1996) Java 2 SDK v 1.2 (1998) Java 2 SDK v 1.3 (2000) Java 2 SDK v 1.4 (2001) CS 3300 Object-Oriented Concepts Introduction to Java 12 2

3 Java IDE Tools JBuilder Microsoft Visual J++ (no longer exist) Symantec Café (no longer exist) Forte or Sun One Studio by Sun MicroSystems IBM Visual Age for Java Java Run-Time Architecture Platform independent Security efficiency CS 3300 Object-Oriented Concepts Introduction to Java 13 CS 3300 Object-Oriented Concepts Introduction to Java 14 Program Execution Models Compilation Translates the source code of a program into machine code Platform dependent Interpretation Directly parse and execute the source code of a program without generating machine code Java Virtual Machine Stage 1 -- Compilation of the source code to bytecode Stage 2 -- Execution of bytecode Interpretation JIT (Just-in-time) compilation Direct execution -- use firmware, embedded java bytecode in a chip CS 3300 Object-Oriented Concepts Introduction to Java 15 CS 3300 Object-Oriented Concepts Introduction to Java 16 Compiling Java Programs Executing Applications Java Source Code Java Compiler Interpreter Compiler Java chip Native Machine code CS 3300 Object-Oriented Concepts Introduction to Java 17 CS 3300 Object-Oriented Concepts Introduction to Java 18 3

4 Java Opcode (1-byte) operand 1 Security of JVM Shield memory addresses Verification of bytecode Run-time security manager operand 2 CS 3300 Object-Oriented Concepts Introduction to Java 19 CS 3300 Object-Oriented Concepts Introduction to Java 20 A Simple Application //This application program prints Welcome //to Java! public class Welcome public static void main(string[] args) System.out.println("Welcome to Java!"); CS 3300 Object-Oriented Concepts Introduction to Java 21 A Simple Applet /* This is an example of Java applets */ import java.awt.graphics; public class WelcomeApplet extends java.applet.applet public void paint (Graphics g) g.drawstring("welcome to Java!",10,10); CS 3300 Object-Oriented Concepts Introduction to Java 22 Creating an HTML File <html> <body> <applet code="welcomeapplet.class" width = 100 height = 40> </applet> </body> </html> Applications vs. Applets Similarities Differences CS 3300 Object-Oriented Concepts Introduction to Java 23 CS 3300 Object-Oriented Concepts Introduction to Java 24 4

5 Security Restrictions on Applets Applets are not allowed to read from, or write to, the file system of the computer viewing the applets. Applets are not allowed to run any programs on the browser s computer. Applets are not allowed to establish connections between the user s computer and another computer except with the server where the applets are stored. CS 3300 Object-Oriented Concepts Introduction to Java 25 5

Java Programming Language Mr.Rungrote Phonkam

2 Java Programming Language Mr.Rungrote Phonkam rungrote@it.kmitl.ac.th Contents 1. Intro to Java. 2. Java Platform 3. Java Language 4. JDK 5. Programming Steps 6. Visual Programming 7. Basic Programming