Java Reference
In-Depth Information
Implement Modules in JNLP
The modules obtained in the previous step must be translated into JNLP constructs.
This usually involves the specification of language and platform information for the involved
resources.
Optional packages have to be installed by custom installers; hence, an installer extension is
needed. When deploying reusable libraries, a component extension is needed (though it is not
necessary). The required JRE can be defined through the
j2se
element.
The following table describes the most frequent cases. Note that this table recaps imprecisely
what was said before; for example, when we mention the
installer-desc
JNLP element, we
mean the proper creation of an extension installer descriptor file, and so on.
Type Of Application Resource
Final JNLP Element
Java classes and other files
jar
Third-party and other reusable libraries
component-desc
Optional packages
installer-desc
JRE
j2se
Other resources
nativelib
,
jar
This is a basic procedure, and it is not exhaustive. Special cases will require ad-hoc installer
classes, and so on.
Create JNLP Resources
This step involves the preparation of the following items, for example in the following order:
1. JNLP resources. They are created by properly packaging the application resources, even-
tually signing the resulting JAR files. JNLP resources include all the items mentioned by
JNLP files, including icons, HTML pages, and so on.
2. The hierarchical structure of the JNLP resources obtained in the previous step is care-
fully thought out, in order to access such resources through URLs.
3. Finally, JNLP files creation can be concluded because all URLs are defined, and only lit-
tle details such as the attributes of the main JNLP file
information
element are left.
Also, all other details needed to finish the JNLP files are defined now (such as the setting
of system properties).
Note that this is just one possible order to accomplish the creation of JNLP resources; feel free
to follow your own style. What is important is to obtain all the final pieces ready to be
deployed on the server.
