Java Programming Lecture 1

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Java Programming Lecture 1

• Instructors
• Fu-Chiung Cheng
• (???)
• Associate Professor
• Computer Science Engineering
• Tatung University
• email cheng_at_cse.ttu.edu.tw
• http// www.cse.ttu.edu.tw/fccheng

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Contents (chapter 1)

• Short History
• Java Development tools
• Install JBuilder Tool and Samples
• Getting Started With Java Programming
• Compiling and Running a Java Application
• Compiling and Running a Java Applet

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History

• James Gosling
• Oak (Embedded consumer electronic appliances)
• Java, May 20, 1995, Sun World
• HotJava
• The first Java-enabled Web browser

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Java Development Tools

• JDK1.0, JDK1.0.2, JDK1.1, JDK1.2
• The New Java 2 Name
• Inprise JBuilder (RAD)
• Microsoft Visual J
• Symantec Café (RAD)
• Rouge Wave JFactory
• Sun Java Workshop
• IBM Visual Age for Java (RAD)

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Install JBuilder and Samples

• Install JBuilder 3 University
• Install Sample Programs
• Setup JDK 1.2.2 environment
• Set classpathclasspathc\jbbook
• Set pathpathc\jdk1.2.2\bin
• Check Java Home
• www.javasoft.com

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Getting Started with Java Programming

• A Simple Java Application
• Compiling Programs
• Executing Applications
• A Simple Java Applet
• Viewing Java Applets
• Applications vs. Applets

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A Simple Application

• Example 1.1
• //This application program prints Welcome
• //to Java!
• public class Welcome
• public static void main (String args)
• System.out.println("Welcome to Java!")

Run
Source
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Compiling Programs

• On command line
• javac file.java

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Executing Applications

• On command line
• java classname

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Example

• javac Welcome.java
• java Welcome
• output...

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A Simple Applet

• Example 1.2
• / 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)

Source
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Creating an HTML File

• lthtmlgt
• ltbodygt
• ltapplet code"WelcomeApplet.class"
• width 100 height 40gt
• lt/appletgt
• lt/bodygt
• lt/htmlgt

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Viewing Java Applets
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Applet Viewer Utility

• appletviewer htmlfile.html
• Example
• appletviewer WelcomeApplet.html

Run Applet Viewer
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Applications vs. Applets

• Similarities
• Differences

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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 browsers computer.
• Applets are not allowed to establish connections
  between the users computer and another computer
  except with the server where the applets are
  stored.