Fix NoSuchMethodError when using Buildship 3.1.5

Support both Collection and Map values from `modelProvider.fetchModels`
so that the plugin can work with Builship 3.1.5.

Fixes gh-260

Author: philwebb

spring-javaformat-eclipse/io.spring.javaformat.eclipse/src/io/spring/javaformat/eclipse/gradle/GradleProjectSettingsConfigurator.java

@@ -20,6 +20,7 @@
 import java.io.IOException;
 import java.util.Collection;
 import java.util.LinkedHashSet;
+import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
 
@@ -76,8 +77,7 @@ private void configureProject(IProject project, IProgressMonitor monitor) throws
 		Optional<GradleBuild> build = workspace.getBuild(project);
 		if (build.isPresent()) {
 			ModelProvider modelProvider = ((InternalGradleBuild) build.get()).getModelProvider();
-			Collection<EclipseProject> rootProjects = modelProvider.fetchModels(EclipseProject.class,
-					FetchStrategy.FORCE_RELOAD, this.tokenSource, monitor);
+			Collection<EclipseProject> rootProjects = getRootProjects(monitor, modelProvider);
 			EclipseProject eclipseProject = findProjectByName(rootProjects, project.getName());
 			if (hasSpringFormatPlugin(eclipseProject)) {
 				ProjectSettingsFilesLocator locator = new ProjectSettingsFilesLocator(getSearchFolders(rootProjects));
@@ -86,6 +86,13 @@ private void configureProject(IProject project, IProgressMonitor monitor) throws
 		}
 	}
 
+	@SuppressWarnings("unchecked")
+	private Collection<EclipseProject> getRootProjects(IProgressMonitor monitor, ModelProvider modelProvider) {
+		Object models = modelProvider.fetchModels(EclipseProject.class,
+				FetchStrategy.FORCE_RELOAD, this.tokenSource, monitor);
+		return (Collection<EclipseProject>) ((models instanceof Map) ? ((Map<?, ?>) models).values() : models);
+	}
+
 	private EclipseProject findProjectByName(Iterable<? extends EclipseProject> candidates, String name) {
 		for (EclipseProject candidate : candidates) {
 			if (name.equals(candidate.getName())) {