varargs support

[rukai]

It seems that j4rs does not support calling java methods defined with varargs from rust.
I'll take a look into whats missing for this to work, but if you have any ideas I'd love to hear them.

[rukai]

The readme lists statics as supporting variadics but that doesnt seem possible since static and non-static methods have the same underlying implementation and neither of them support variadics/varargs.

After looking at the implementation, the fix looks fairly straightforward and I should have a PR up soon.

[rukai]

Looking further into it:
There is a test testing that variadics works, so I must be misunderstanding the implementation.
However for some reason a lot of the tests fail when run on my machine:
For example:

running 1 test
test lib_unit_tests::variadic_string_method ... Exception in thread "main" org.astonbitecode.j4rs.errors.InvocationException: While invoking method deploy of Class org.astonbitecode.j4rs.api.deploy.SimpleMavenDeployer
	at org.astonbitecode.j4rs.api.invocation.JsonInvocationImpl.invoke(JsonInvocationImpl.java:74)
Caused by: java.lang.reflect.InvocationTargetException
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:118)
	at java.base/java.lang.reflect.Method.invoke(Method.java:580)
	at org.astonbitecode.j4rs.api.invocation.JsonInvocationImpl.invokeMethod(JsonInvocationImpl.java:198)
	at org.astonbitecode.j4rs.api.invocation.JsonInvocationImpl.invoke(JsonInvocationImpl.java:70)
Caused by: java.io.FileNotFoundException: https://repo.maven.apache.org/maven2/io/github/astonbitecode/j4rs-testing/0.21.0-SNAPSHOT/maven-metadata.xml
	at java.base/sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:2010)
	at java.base/sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1615)
	at java.base/sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:223)
	at java.base/java.net.URL.openStream(URL.java:1325)
	at org.astonbitecode.j4rs.api.deploy.SimpleMavenDeployer.getLatestSnapshotName(SimpleMavenDeployer.java:126)
	at org.astonbitecode.j4rs.api.deploy.SimpleMavenDeployer.generateUrlTagret(SimpleMavenDeployer.java:117)
	at org.astonbitecode.j4rs.api.deploy.SimpleMavenDeployer.deploy(SimpleMavenDeployer.java:78)
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
	... 3 more
FAILED

failures:

---- lib_unit_tests::variadic_string_method stdout ----
ERROR: An Exception was thrown by Java... Please check the logs or the console.
Error: JavaError("org.astonbitecode.j4rs.errors.InstantiationException: Cannot create instance of org.astonbitecode.j4rs.tests.MyTest\n\tat org.astonbitecode.j4rs.api.instantiation.NativeInstantiationImpl.instantiate(NativeInstantiationImpl.java:47)\nCaused by: java.lang.ClassNotFoundException: org.astonbitecode.j4rs.tests.MyTest\n\tat java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:445)\n\tat java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:592)\n\tat java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:525)\n\tat java.base/java.lang.Class.forName0(Native Method)\n\tat java.base/java.lang.Class.forName(Class.java:529)\n\tat java.base/java.lang.Class.forName(Class.java:508)\n\tat org.astonbitecode.j4rs.utils.Utils.forNameEnhanced(Utils.java:60)\n\tat org.astonbitecode.j4rs.api.instantiation.NativeInstantiationImpl.createInstance(NativeInstantiationImpl.java:96)\n\tat org.astonbitecode.j4rs.api.instantiation.NativeInstantiationImpl.instantiate(NativeInstantiationImpl.java:44)\n")

Test failure resolved by: #124