Deploying Java applications as JAR files

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Deploying Java applications as JAR files
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Consider the following project

• This application consists of three files in two
  directories, in packages called se2030.jigloodemo
  and se2030.jigloodemo.hornick

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When you run an application from within Eclipse,
it issues the following command

• java cp D\My Documents\MSOE\Courses\Example
  Programs\se2030\JiglooDemo\bin
  se2030.jigloodemo/JiglooDemoApp
• java is the command that runs the Java Virtual
  Machine
• Same as C\Program Files\Java\jdk1.6.0_03\bin\java
  .exe
• JiglooDemoApp is the name of the main class
• se2030.jigloodemo is the name of the package
  containing the main class (se2030.jigloodemo.horni
  ck is the name of the package containing the ui
  class)
• -cp ltclasspathgt specifies the base directory
  where the .class file(s) for the packages are
  located
• Not including the package subdirectories

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The formal syntax isjava cp ltpathgt ltpackagegt /
ltmain_classgt

• javaw is another command that runs the Java
  Virtual Machine
• without a console window
• ltmain_classgt is the name of the main class
• The one containing the main() method
• ltpackagegt is the name of the package containing
  the main class
• Note the . separator within the package
  specification
• Note the / separator after the package
  specification
• -cp ltclasspathgt specifies the classpath
• the base directory containing the classes that
  make up the application
• If the classes are distributed among more than
  one base directory, then ltdirgt is a
  semicolon-separated list of directory paths

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You can create a shortcut to run the application
from the Desktop
In Windows 7 1. Right-click the Desktop and
select New/Shortcut from the context menu that
appears. 2. Browse to the place on your file
system containing the Java VM, as shown (your
location may be different).
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Creating a shortcut, continued...
3. Type the name for your shortcut that will
appear beneath the shortcut icon on your desktop.
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Creating a shortcut, continued...

• Select Properties of the resulting shortcut icon
  on your desktop. The dialog to the left appears.
• Append the file path to the class file to the
  existing Target, omitting .class.
• If it consists of only a single directory, the
  classpath can be specified in the Start in
  text box, and the -cp option is not needed in
  the Target specification

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Next, consider the following project
This application consists of two source files in
two different classpaths (src and auxiliary), but
the same package (edu.msoe.se2030.demo)
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Using the preceding project as an example

• java cp D\My Documents\MSOE\Courses\Example
  Programs\se2030\JARDemo\src D\My
  Documents\MSOE\Courses\Example Programs\se2030\JAR
  Demo\auxiliary edu.msoe.se2030.demo/JARDemoApp
• JARDemoApp is the name of the main class
• edu.msoe.se2030.demo is the name of the package
  containing the main class
• The classpath must specify both base directories
  where the .class file(s) are located (because
  they differ)
• Separated by a semicolon

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Finally, consider the following project
This application consists of one source file, but
the WinplotterDemo project uses an external
library (winPlotter.jar) containing several
user-written classes
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Using this last project as an example

• java cp D\My Documents\MSOE\Courses\Example
  Programs\se2030\WinplotterDemo D\My
  Documents\MSOE\Courses\Example Programs\jars\winPl
  otter.jar edu.msoe.se2030.plot/WinplotterDemoApp
  
• WinplotterDemoApp is the name of the main class
• edu.msoe.se2030.plot is the name of the package
  containing the main class
• The classpath specifies both the directory where
  the WinplotterDemoApp.class file is located
• As well as the path to the winPlotter.jar file
  that contains the external user-written classes

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A Java Archive (JAR) file enables you to bundle
multiple files into a single archive file

• A JAR file is essentially a ZIP file with
  specific contents
• The files you want to zip into the file
• .class files
• Source files (.java) if you want to enable
  debugging
• Javadoc files if you want to provide
  context-sensitive help for the classes in the JAR
  file
• A manifest file (MANIFEST.MF)
• Which specifies whats in the JAR file

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The jar utility is used to create JAR files

• jar cfm ltjarfilegt ltmanifestgt ltfilesgt
• jar is the command that runs the jar utility
• Same as C\Program Files\Java\jdk1.6.0_03\bin\jar.
  exe
• jarfile is the name of the JAR file you want to
  create
• manifest is the name of a file containing
  manifest information
• Note  The contents of the manifest must be
  encoded in ansi.
• files specifies the files you want to place in
  the JAR file
• Separated by spaces

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To bundle files in the same directory into a JAR
file

• jar cfm MyApp.jar manifest.txt edu/msoe/se2030/dem
  o/JARDemoApp.class edu/msoe/se2030/demo/DemoDispla
  yer.class
• This assumes
• you are issuing the jar command from within the
  directory of D\My Documents\se2030\JARDemo\bin
• manifest.txt is in the same bin directory
• edu/msoe/se2030/demo is the name of the package
  such that all class files are located in D\My
  Documents\JARDemo\bin\edu\msoe\se2030\demo
• the capitalization of the class filename is
  identical to the capitalization of the class
  itself (be careful on Windows because the OS is
  case-insensitive but Java is NOT)

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Manifest details

• Manifest.txt is an ansi text file (created with
  Notepad or similar text editor) containing the
  following text
• Manifest-Version 1.0
• Created-By 1.6.0_03-b05 (Sun Microsystems Inc.)
• Main-Class edu.msoe.se2030.demo.JARDemoApp

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The case where .class files are in separate
directories and/or separate packages

• jar cfm MyApp.jar manifest.txt
• C ./bin1 edu/msoe/se2030/demo/JARDemoApp.class
  C ./bin2 edu/msoe/se2030/auxiliary/DemoDisplayer
  .classThis assumes
• you are issuing the jar command from within a
  project directory such as D\My
  Documents\JARDemo and bin1 and bin2 are
  subfolders
• manifest.txt is in the same project directory
• edu/msoe/se2030/demo and edu/msoe/se2030/auxiliary
  are the names of the packages such that the
  class files are located in D\My
  Documents\JARDemo \bin1\edu\msoe\se2030\demo and
  D\My Documents\JARDemo \bin2\edu\msoe\se2030\auxi
  liary

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If your JAR file references other JAR files (like
WinPlotter.jar)

• The Manifest.txt must contain a reference to the
  location of the other JAR file(s)
• Manifest-Version 1.0
• Created-By 1.6.0_03-b05 (Sun Microsystems Inc.)
• Main-Class edu.msoe.se2030.demo.JARDemoApp
• Class-Path ./winPlotter.jar

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To deploy your application, you just have to copy
the JAR file to someplace (e.g. C\temp) on the
target PC

• To run the application bundled within a JAR file,
  issue the following command
• java jar C\temp\MyApp.jar
• Or create a shortcut containing the above command

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Online tutorial

• Packaging Programs in JAR files
• http//java.sun.com/docs/books/tutorial/deployment
  /jar/index.html