Help: Packing Central Perk with Marcel

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Help: Packing Central Perk with Marcel
MageLang Institute

Help is available for each task, or you can go straight to the solution source code.

Task 1

Take the final CentralPerk.java, PerkEvent.java, and PerkListener.java files from the From Kiva Han to Central Perk exercise and place them in their own package.

Create a new subdirectory, copy the files to subdirectory, and include a line as the first line of each file that says "package DirName;", where DirName is the subdirectory you created. For instance, if the subdirectory you created is "Marcel", the line would be "package Marcel;".

Task 2

Create the associated BeanInfo class for CentralPerk. In it, set the descriptive name of the Bean to "Billboard".

The class needs to be called CentralPerkBeanInfo and should subclass SimpleBeanInfo. The getBeanDescriptor method should look like this: public BeanDescriptor getBeanDescriptor() { BeanDescriptor bd = new BeanDescriptor(CentralPerk.class); bd.setDisplayName("Billboard"); return bd; } A warning note about compiling the BeanInfo class. You need to ensure your CLASSPATH environment variable is set properly for this to find the CentralPerk.class file. Because this is in a package, you either need to compile from its parent directory, or include the package's base directory in the CLASSPATH.

Task 3

The next thing you need to do is to create a manifest file for the Bean's .jar file. Normally, the jar command can create the manifest for you. However, in order for the Bean-builder tool to know that one of the .class files is a Bean, you have to manually create a manifest file. For every .class file, you need to include a line of the form:

Name: Marcel/CentralPerk.class

Make sure you use a UNIX-style separator character ('/') between directory names and filename. The DOS-style separator ('\') is not valid here.

For the class that is a Bean, include a second line after the Name: line

Java-Bean: True

Between each entry, include a blank line.

The actual filename you use for the manifest does not matter.

Name: Marcel/CentralPerk.class
Java-Bean: True

Name: Marcel/CentralPerkBeanInfo.class

Name: Marcel/PerkEvent.class

Name: Marcel/PerkListener.class

Using a tool like make/nmake makes this much easier, especially when the number of classes increases.

Task 4

From the directory above your package directory, create the jar file.

Assuming the manifest file is called manifest, and your classes are in the Marcel package, the command to do this is:

jar cfm Perk.jar manifest Marcel\*.class

Task 5

Startup the BeanBox.

See the

BDK Introduction with John Wayne exercise for instructions.

Task 6

Load the jar file with the 'LoadJar' menu choice under the 'File' menu. The Billboard bean should now appear in the Toolbox. Try it out.

If you get a duplicate name exception from the BeanBox when loading the .jar file, this means that the BeanBox locates the jar-file class in the CLASSPATH. Run the beanbox from another directory and/or reset your CLASSPATH. The run.sh and run.bat scripts in the Beanbox directory do this for you.