CIT CS Workshop: June 2001 Lab 7	Computer Science Department

Lab Assignment 7

The purpose of this assignment is to

• review concepts from previous Labs
• introduce you to Java Applets
• explore more JavaScript concepts

NOTICE

When you are happy with your personal web page,

  let us add it to the class web page

Instructions

• Printing out this page:
  1. Remember to print out this Web page using lp -d flute

• Observing Java Applets
  1. Click here
       for some examples of Java applets

  2. See http://www.cs.colostate.edu/workshop/Labs/AppletExamples.html
       for more examples of Java applets

• Considering Java Applet Source Code
  1. For all the examples above,
       the Java source code that produced these is available
     Look at this source code
       and try to figure out how the picture was drawn

  2. For more information on drawing figures in applets,
       click here

• Comparing Java to HTML and JavaScript
  1. Java is a full-fledged programming language
       while JavaScript is a scripting language and
         HTML is much like a word-processing language

  2. HTML is interpreted into Web page format by a Web browser
       JavaScript is likewise translated
  3. However, Java source code does not make sense to a browser

  4. Java source code must first be compiled into bytecode
       The bytecode can be interpreted by any Java-enabled browser

• Compiling Java Programs
  1. Copy one (or more) of the Java applet source codes into your own directory

  2. In a new dterm window, type
             rlogin basie, or
             rlogin brubeck, or
             rlogin coltrane, or
             rlogin gillespie

     These four machines are Sun workstations, not HP machines
         They contains the software needed to compile Java programs
             The HP machines do not

  3. You will be prompted to give your loginname
       and password again

  4. Then go to the subdirectory containing your Java programs

  5. Type
             /usr/bin/javac StickMan.java, or
             /usr/bin/javac SnowMan.java, or
             /usr/bin/javac Car.java, or
             /usr/bin/javac FaceWithHat.java
       depending on which Java program you want to compile

  6. The compilation process produces a file with the same name
       but with the extension .class instead of .java

• Incorporating Java Applets into your Web pages
  1. Go back and view the desired applet
       on one of the Examples pages

  2. Click on View/Source
       and copy the HTML source between and including
         the beginning and ending <APPLET> tags

  3. Insert this HTML code in your Web page
         (You may have to change the CODEBASE value
             to match your Java directory)

  4. Check out the Web page to make sure it works correctly
       with the new applet

• Modifying Java Applet Programs
  1. Choose one of the Java applet source codes
       Any of these four applets are acceptable choices
         (Please do not pick an animated applet)

  2. Copy this code into your own Java directory

  3. Using your editor, make minor changes to the code
         E.g. adding your name to StickMan.java
             or buttons to the SnowMan's chest

  4. Try to recompile the applet program
         (There may be errors -- ask for help if needed)

  5. Once it compiles successfully,
       check it out in your Web page
     If you are not happy with the result,
       repeat these last three steps

• Finishing up your Web page
  1. Please try to finish up your personal Web page today
       so that you can start with the group project tomorrow

  2. Let us know when you are ready to have it added to the workshop page