Hour 4: Understanding How Java Programs Work

NOTES AND CORRECTIONS

• Line 3 of Listing 4.3 contains a reference to com.sun.java.swing.JApplet. This is correct if you're using JDK 1.2 Beta 4, but the name was changed in subsequent versions of JDK 1.2. If you're not using 1.2 Beta 4, replace com.sun.java.swing with javax.swing. The new Line 3 is the following:
  • public class RootApplet extends javax.swing.JApplet {
• At the end of this hour, the workshop is a guided tour of several Java applets. Each of these shows how a Java program on the Web can be modified with the use of the PARAM tag. Visit each of the following pages with the current version of Netscape Navigator or Microsoft Internet Explorer. The HTML tag used to create the applet also will be displayed.  
  • The Frog applet
  • The Puzzle applet
  • The RandomText applet

SOURCE FILES

• RootApplet.java (first version)
• RootApplet.class (first version)
• RootApplet.html (first version)
• RootApplet.java (second version)
• RootApplet.class (second version)
• RootApplet.html (second version)
• Root.java
• Root.class
• NewRoot.java
• NewRoot.class

READER QUESTIONS

• None

ACTIVITIES

• Solution #1: Visit Developer.Com's Java directory and use the search term Marquee to display applets that display text in a marquee format.
• Solution #2: BestTime.java, BestTime.class, and BestTime.html.