Applet Basics

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Applet Basics
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What well cover

• The difference between Applets and applications
• How Applets work
• The ltApplet gt tag
• Passing parameters
• Storing Applets in jar files

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Applets vs. Applications

• Appications run standalone, Applets run in
  browsers
• Applets run in a sandbox that controls access
  to system resources
• Applets have access to structures provided by the
  browser

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How Applets work

• Browser versions of Java lag behind the released
  versions of the JDK
• Java Applets extend from java.applet.Applet
• The jvm running in the Browser will directly call
  certain methods if they exist init(),
  start(),stop(),destroy()

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The ltAppletgt tag

• The basic format is ltAPPLET CODEX WIDTH99
  HEIGHT99gtlt/APPLETgt
• ALIGN attribute
• HSPACE and VSPACE
• CODEBASE
• ARCHIVES

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Passing parameters

• Parameters are passed to Applets with the PARAM
  tag in the HTML, ltPARAM NAMExx VALUEXX
• In the Applets .java file use the
  getParameter(XX) to retrieve the contents of
  the PARAM tag

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Storing Applets in jar files

• Browsers that support version 1.1 of Java can use
  Jar files.
• Jar files are Java Archive Files, combinations of
  multiple class files and a manifest.
• Jar files are created using the jar command

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What we covered

• Applets vs Applications
• Applet workings
• The ltApplet gt tag
• Parameters
• Jar files