CS 4773 Object Oriented Systems
About the course

Syallabus

First Assignment

What the course is not.

What the course is.

What is Java?

• simple
• object-oriented
• distributed
• interpreted
• robust
• secure
• architecture-neutral
• portable
• high-performance
• multithreaded
• dynamic
• general-purpose

• buzzword-compliant

Most notable is what it does not contain:

• global variables outside the class hierarchy
• goto
• pointer arithmetic
• malloc and free
• system dependent data types
• varargs
• separate header files
• preprocessor
• structures
• simple types passed by reference
• multiple inheritance
• operator overloading

Setting up your account

should give

java version "1.2.1"
Solaris VM (build Solaris_JDK_1.2.1_02, native threads, sunwjit)

Compile with
javac programname.java

Run applications with
java programname

Run applets with
appletviewer programname.java

This assumes that your java source has an HTML heading as a comment.

First Assignment Example

/* < Applet code = ShowD
     width = 400 height = 300 >
   < /Applet >
*/

import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;

public class ShowD extends Applet implements ActionListener {
   Label prompt;
   TextField input;
   double val;

   public void init() {
      prompt = new Label("Enter a number");
      add(prompt);
      input = new TextField(20);
      input.addActionListener(this);
      add(input);
      setBackground(Color.cyan);
   }

   public void paint(Graphics g) {
      g.drawString("The number is: "+val,50,80);
      g.drawString("One hundred times the value is: "+100*val,50,110);
      g.drawString("This program was modified by Steven Robbins",50,150);
   }

   public void actionPerformed(ActionEvent e) {
      if (e.getSource() == input) {
         val = Double.valueOf(input.getText()).doubleValue();
         repaint();
      }
   }

}

This creates a file called ShowD.class

Run this using:
appletviewer ShowD.java

Put it on the web!

Next topic: The Java Language