// mainEcoreFile = ... (a java.io.File referencing my .ecore file - e.g., /home/vitor/A-CAD/models/acad.ecore)
// targetFolder = ... (a java.io.File referencing the directory where I want the sources to be generated - e.g., /home/vitor/A-CAD/src)
// basePackage = ... (a String with the base package - e.g., "it.unitn.disi.acad.models")

/* STEP 1: .genmodel file generation */

// Initializes the resource set.
ResourceSet resourceSet = new ResourceSetImpl();
resourceSet.getURIConverter().getURIMap().putAll(EcorePlugin.computePlatformURIMap());

// "Opens" the ecore file and retrieves its package.
IPath mainPath = new Path(mainEcoreFile.getAbsoluteFile().getCanonicalPath());
URI ecoreURI = URI.createFileURI(mainPath.toString());
Resource resource = resourceSet.getResource(ecoreURI, true);
EPackage mainPackage = (EPackage) resource.getContents().get(0);

// Determines the name of the .genmodel file (same as .ecore with different extension).
IPath genModelPath = mainPath.removeFileExtension().addFileExtension("genmodel");
URI genModelURI = URI.createFileURI(genModelPath.toString());

// Creates the genmodel object in memory and sets its attributes.
IPath modelDir = new Path(targetFolder.getAbsoluteFile().getCanonicalPath()).makeRelative();
GenModel mainGenModel = GenModelFactory.eINSTANCE.createGenModel();
mainGenModel.setModelDirectory(modelDir.toString());
mainGenModel.getForeignModel().add(mainPath.toString());
mainGenModel.initialize(Collections.singleton(mainPackage));
mainGenModel.setModelName(mainPath.removeFileExtension().lastSegment());

// Sets the base package in the main package of the genmodel.
GenPackage genPackage = mainGenModel.getGenPackages().get(0);
genPackage.setBasePackage(basePackage);

// Creates the genmodel resource and saves it in the file system.
Resource genModelResource = Resource.Factory.Registry.INSTANCE.getFactory(genModelURI).createResource(genModelURI);
genModelResource.getContents().add(mainGenModel);
resourceSet.getResources().add(genModelResource);
genModelResource.save(Collections.EMPTY_MAP);


/* STEP 2: Java source code generation */

// Creates a null progress monitor to ignore the progress.
IProgressMonitor progressMonitor = new NullProgressMonitor();

// Retrieves the genmodel object from the genmodel resource and checks that it's valid.
GenModel genModel = (GenModel) genModelResource.getContents().get(0);
IStatus status = genModel.validate();
if (!status.isOK()) {
	Diagnostic diagnostic = genModel.diagnose();
	throw new IllegalStateException("Genmodel file is not valid. Diagnostic message is: " + diagnostic.getMessage()); //$NON-NLS-1$
}

// Creates a generator from the model and configures the generation.
Generator generator = new Generator(); // Using org.eclipse.emf.codegen.ecore.generator.Generator
generator.setInput(genModel);
genModel.setForceOverwrite(true);
genModel.reconcile();
genModel.setCanGenerate(true);
genModel.setValidateModel(true);
genModel.setUpdateClasspath(false);
genModel.setCodeFormatting(true);

// Generates the source code at the target folder.
IPath path = new Path(modelName);
CodeGenUtil.EclipseUtil.findOrCreateContainer(path, true, path, BasicMonitor.toIProgressMonitor(CodeGenUtil.EclipseUtil.createMonitor(progressMonitor, 1)));
generator.generate(genModel, GenBaseGeneratorAdapter.MODEL_PROJECT_TYPE, CodeGenUtil.EclipseUtil.createMonitor(progressMonitor, 1));

CodeGenUtil.EclipseUtil.findOrCreateContainer()

sefms-disi-unitn/Unagi/blob/master/it.unitn.disi.unagi.application/src/it/unitn/disi/unagi/application/internal/services/ManageModelsService.java