Creating a netlet descriptor

Here is how we generate that XML netlet descriptor. A netlet descriptor simply says what JARs a netlet needs to run, where its start point is and any parameters it needs. The one parameter it does need is an XML warrant. We can download this from http://www.jtrix.org/warrant/hello-warrant.xml and we'll save it into a file called hello-warrant.xml.

To create the netlet descriptor we need to say what type of XML file we're generating (a netlet descriptor), what the main class is, what JARs are needed and what directories hold them, the parameter (the warrant) for start-up, and what we the resulting XML file to be called:

% ls
hello-warrant.xml  hello1.jar
% jtrixmaker -type netlet -outfile hello1-client.xml \
     -jardirs /usr/lib/jtrix . -jars libjtrix.jar hello1.jar \
     -classname org.jtrix.project.helloworld.Hello1Client \
     -param {warrant:hello-warrant.xml}
% ls
hello-warrant.xml  hello1-client.xml  hello1.jar
% 

You might need to change the Jtrix binaries directory for your system. In the end we have the netlet descriptor hello1-client.xml.

Now we can run the netlet with Jnode as shown above.

As a final comment, some people have found problems with this example if they are working from behind a fussy firewall, and if so then all such examples will exhibit the same problems. The current solutions are (1) to run such examples from a location without such a firewall, or (2) jump to the examples in Chapters , and  which are local only, and do not require external connections. Also, look on http://www.jtrix.org which will have some discussion on this issue.