I also reworked how the Java and Kotlin demos
process errors in the command line arguments.
Using exceptions that are caught by main() rather
than directly exiting the process where the errors
are detected.
I found that it is possible to use the "||" operator
in Windows batch files, and it works the same as the
"||" operator in bash scripts.
This inspired me to rework the bash scripts and
Windows batch files for running the Java/Kotlin demo
tests to be much more compact using functions/subroutines.
The best part is, the new approach will make it much
easier to add more demo tests in the future.
Removed the "now" test from Java demos, because it
does not follow the same pattern as the other demos,
plus it is not really demonstrating astronomy calculations.
Starting working on the Positions.kt demo; but not finished yet.
As I add more Java demos, it will make the code more
compact to factor out argument count checking, etc.
Reworked as a table-driven model instead of using `switch`,
so that I will be able to add new demos more concisely.
Run the Java demo unit test as part of the automated test suite.
If the test fails, print the xml test results to the screen,
so if it happens in GitHub Actions, we can see what went wrong
and diagnose the problem.
This is the first substantial demo of using
the Kotlin version of Astronomy Engine from
a Java program.
Structured the README.md so I can keep adding more and
more demos as separate Java class files.
The `demotest` script builds the code and will run
each demo one at a time, verifying each one's output.
The Kotlin version of Astronomy Engine was using Java
classes like `Date` and `GregorianCalendar`.
Reworked the code to use a completely self-contained
representation of calendar date/time, just like the C version does.
Now Astronomy Engine does not depend on anything outside of
the Kotlin standard library. This should allow us to use
Astronomy Engine for Kotlin Native apps, Web Assembly, etc.
Updated Java demo to use the new method Time.fromMillisecondsSince1970.
Moved the step that creates the fatJar into
the main build process for Kotlin. This is
needed to run the Java demos, and it is good
to fail early if it cannot be built.
Renamed AstroTime to Time.
Renamed AstroVector to Vector.
For some reason this breaks the Java demo build.
I'm pushing the broken build anyway to see if
ebraminio can help me fix it.
Restructured the Java code so we pass in command
line arguments to select which demo we want to run.
We will also pass in date/time, latitude/longitude,
or whatever numeric data we need for future demos.
Automated test run of the Java demos from the
unit test suite.
Adopted from https://stackoverflow.com/a/63332420
So one can run the demo with `./gradlew jar && java -jar build/libs/astronomy-demo-0.0.1.jar`
instead `./gradlew run`
