Java and XML

[Lucia]

Hello,

I'd like store all constants in my java-Application in an XML-file.
e.g.
<constant>
<name>con</name>
<type>long</type>
<value>10</value>
</constant>

After starting the application, the java class should be able to
create a variable with the name, the type and the value.

In this example, the java class should call the line at runtime:
long con = 10;

Has anyone an idea?

Thanks

Lucia

[Johannes Koch]

Lucia wrote:

Hello,

I'd like store all constants in my java-Application in an XML-file.
e.g.
<constant>
<name>con</name>
<type>long</type>
<value>10</value>
</constant>

After starting the application, the java class should be able to
create a variable with the name, the type and the value.

In this example, the java class should call the line at runtime:
long con = 10;

Has anyone an idea?

Does the XMLEncoder/XMLDecoder in the java.beans package help you?

f'up2 cjlp
--
Johannes Koch
In te domine speravi; non confundar in aeternum.
(Te Deum, 4th cent.)

[Michael Borgwardt]

Lucia wrote:

I'd like store all constants in my java-Application in an XML-file.
e.g.
<constant>
<name>con</name>
<type>long</type>
<value>10</value>
</constant>

After starting the application, the java class should be able to
create a variable with the name, the type and the value.

In this example, the java class should call the line at runtime:
long con = 10;

Has anyone an idea?

In full generality: impossible. You could set the values via the reflection
API, but you'd still have the names and types fixed in the java classes.
You could generate the classes via a custom class loader, but then you
couldn't refer to the variables except via reflection, which would be
a really dumb and unnecessarily complex way to access config data.

All in all, it's simply a very bad idea: lots and lots of complexity
for practically no gain. Why not use a .properties file?

[Steve Slatcher]

Lucia wrote:

Hello,

I'd like store all constants in my java-Application in an XML-file.
e.g.
<constant>
<name>con</name>
<type>long</type>
<value>10</value>
</constant>

After starting the application, the java class should be able to
create a variable with the name, the type and the value.

In this example, the java class should call the line at runtime:
long con = 10;

Has anyone an idea?

It wouldn't work exactly as you describe, but you could achieve a similar
effect with JAXB. Using JAXB you can easily convert an XML file into a
configuration object, and then you could get your "constants" from that
object.