Make it possible to override the classpath

This is an internal implementation change so that plugins reusing this code can customize the classpath provider.

Author: melix

native-gradle-plugin/src/main/java/org/graalvm/buildtools/gradle/internal/NativeImageCommandLineProvider.java

@@ -109,12 +109,8 @@ public List<String> asArguments() {
  List<String> cliArgs = new ArrayList<>(20);
 
  cliArgs.add("-cp");
- if (classpathJar.isPresent()) {
- cliArgs.add(classpathJar.get().getAsFile().getAbsolutePath());
- } else {
- cliArgs.add(options.getClasspath().getAsPath());
- }
-
+ String classpathString = buildClasspathString(options);
+ cliArgs.add(classpathString);
  appendBooleanOption(cliArgs, options.getDebug(), "-H:GenerateDebugInfo=1");
  appendBooleanOption(cliArgs, options.getFallback().map(NEGATE), "--no-fallback");
  appendBooleanOption(cliArgs, options.getVerbose(), "--verbose");
@@ -152,6 +148,26 @@ public List<String> asArguments() {
  return Collections.unmodifiableList(cliArgs);
  }
 
+ /**
+ * Builds a classpath string from the given classpath elements.
+ * This can be overridden by subclasses for special needs. For
+ * example, the Micronaut plugin requires this because it's going
+ * to build images within a docker container, which makes it so
+ * that the paths in the options are invalid (they would be prefixed
+ * by a Windows path).
+ * @param options the native options
+ * @return the classpath string
+ */
+ protected String buildClasspathString(NativeImageOptions options) {
+ String classpathString;
+ if (classpathJar.isPresent()) {
+ classpathString = classpathJar.get().getAsFile().getAbsolutePath();
+ } else {
+ classpathString = options.getClasspath().getAsPath();
+ }
+ return classpathString;
+ }
+
  private static void appendBooleanOption(List<String> cliArgs, Provider<Boolean> provider, String whenTrue) {
  if (provider.get()) {
  cliArgs.add(whenTrue);