Java Reference
In-Depth Information
to the compiled file, you need a manifest prototype, which needs the following entries as a
minimum; you can also put such information as your vendor URL or a copyright notice:
Name: LabelText.class
Java-Bean: true
If these lines are stored in a file called
LabelText.stub
, we can prepare the whole mess for use
as a bean by running the
jar
command (see
Archiving with jar
). Because the JAR file must
contain the class files in their correct package location (see
Creating a Package
)
, and because
Examples
), I start off in the source directory and refer to the class file by its full path (the
Stub file can be anywhere, but I keep it with the source file so I can find it easily, thus I have
to refer to it by its full path, too):
$
cd $js/darwinsys/src
$
jar cvfm labeltext.jar com/darwinsys/swingui/LabelText.stub \
com/darwinsys/swingui/LabelText.class
added manifest
adding: com/darwinsys/swingui/LabelText.class(in=1607) (out=776)(deflated 51%)
$
Of course, in production you would want to automate this with a build tool such as Ant (see
Automating Compilation with Apache Ant
) or Maven (see
Automating Dependencies, Com-
Now we're ready to install
labeltext.jar
as a JavaBean. However, the curious may wish to ex-
amine the JAR file in detail. The
x
option to
jar
asks it to extract files:
$
jar xvf labeltext.jar
created: META-INF/
extracted: META-INF/MANIFEST.MF
extracted: com/darwinsys/swingui/LabelText.class
$
The
MANIFEST.MF
file is based on the manifest file (
LabelText.stub
); let's examine it:
$
more META-INF/MANIFEST.MF
Manifest-Version: 1.0
Created-By: 1.4.2_03 (Apple Computer, Inc.)
