Simple java class to create the basic files of your application, within the structure of your architecture.

SimpleCreateCRUD.java

public class SimpleCreateCRUD {

	private static final Charset charset = StandardCharsets.UTF_8;

	private static final String ROOT = System.getProperty("user.dir")
			+ "//src//main//java//";
	
	private static final String MODELS_FOLDER = ROOT + "models//";

	public static void main(String[] args) throws IOException {
		@SuppressWarnings("resource")
		Scanner sc = new Scanner(System.in);

		System.out.println("****************************************************************");
		System.out.println("***********           Simple CRUD CLI           ****************");
		System.out.println("****************************************************************");
		System.out.println();
		System.out.println("Type the name your Entity/Model:");

		String entity = sc.next();

		for (EntityFileType fileType : getEntityFileTypeList()) {
			
			System.out.println(String.format("*********** Creating file from the template: '%s'", fileType.getTemplate()));
			
			Path path = Paths.get(MODELS_FOLDER + fileType.getTemplate());
			
			String content = replaceTextInFile(path, entity);
			
			String fileName = entity + fileType.getType();
			
			Path pathResource = Paths.get(ROOT + fileType.getRelativePath() + fileName);
			
			if (!createFile(pathResource, content))
				continue;
			
			System.out.println(String.format("*********** File '%s' created success", fileName));
			System.out.println(String.format("*********** Location: '%s'", ROOT + fileType.getRelativePath() + fileName));
			System.out.println();
		}
	}

	public static String replaceTextInFile(Path pathTemplate, String entity) throws IOException {

		String content = new String(Files.readAllBytes(pathTemplate), charset);

		content = content.replaceAll(":ENTITY:", entity);
		content = content.replaceAll(":ENTITY_LOWER:", entity.substring(0, 1).toLowerCase() + entity.substring(1));

		return content;
	}

	public static boolean createFile(Path path, String content) throws IOException {
		File file = new File(path.toString());
		
		if (file.exists()) {
			System.out.println(String.format("*********** ALERT! File '%s' alredy exists!", path));
			System.out.println();
			return false;
		}
		
		Files.write(path, content.getBytes(charset));
		return true;
	}

	public static List<EntityFileType> getEntityFileTypeList() {

		List<EntityFileType> list = new ArrayList<>();

		list.add(new EntityFileType("model//", ".java", "Template"));

		list.add(new EntityFileType("repository//", "Repository.java", "TemplateRepository"));
		list.add(new EntityFileType("repository//", "RepositoryQuery.java", "TemplateRepositoryQuery"));
		list.add(new EntityFileType("repository//impl//", "RepositoryImpl.java", "TemplateRepositoryImpl"));

		list.add(new EntityFileType("resource//", "Resource.java", "TemplateResource"));

		list.add(new EntityFileType("service//", "Service.java", "TemplateService"));
		list.add(new EntityFileType("service//impl//", "ServiceImpl.java", "TemplateServiceImpl"));

		return list;
	}

	static class EntityFileType {

		private String relativePath; // -- //resource//
		private String type; // -- Resource.java
		private String template; // -- //TemplateResource

		public EntityFileType(String relativePath, String type, String template) {
			super();
			this.relativePath = relativePath;
			this.type = type;
			this.template = template;
		}

		public String getRelativePath() {
			return relativePath;
		}

		public String getType() {
			return type;
		}

		public String getTemplate() {
			return template;
		}

	}

}

Template

@Entity
@Table(name = ":ENTITY_LOWER:")
public class :ENTITY: implements Serializable {

	private static final long serialVersionUID = 1L;
	
	private Long id:ENTITY:;
	
	@Id
	@GeneratedValue(strategy = GenerationType.TABLE, generator = "sequencial")
	@TableGenerator(initialValue = 100, name = "sequencial", table = "sequencial", valueColumnName = "valor", pkColumnName = "nome", pkColumnValue = ":ENTITY_LOWER:", allocationSize = 1)
	@Column(name = "id_:ENTITY_LOWER:")
	public Long getId:ENTITY:() {
		return id:ENTITY:;
	}
	public void setId:ENTITY:(Long id:ENTITY:) {
		this.id:ENTITY: = id:ENTITY:;
	}
	
}

TemplateRepository

public interface :ENTITY:Repository extends JpaRepository<:ENTITY:, Long>, :ENTITY:RepositoryQuery {

}

TemplateRepositoryImpl

public class :ENTITY:RepositoryImpl extends AbstractRepository<:ENTITY:, :ENTITY:QueryFilter> implements :ENTITY:RepositoryQuery {

	@Override
	public Class<:ENTITY:> getEntityClass() {
		return :ENTITY:.class;
	}

	@Override
	public List<Predicate> getRestrictions(:ENTITY:QueryFilter filter, CriteriaBuilder builder, Root<:ENTITY:> root) {
		return null;
	}

}

TemplateRepositoryQuery

public interface :ENTITY:RepositoryQuery extends Repository<:ENTITY:, :ENTITY:QueryFilter> {
	
}

TemplateResource

@RestController
@RequestMapping("/api/:ENTITY_LOWER:")
public class :ENTITY:Resource extends AbstractResource<:ENTITY:, :ENTITY:QueryFilter> {

	@Autowired
	:ENTITY:Service :ENTITY_LOWER:Service;
	
	@Override
	public Service<:ENTITY:> getService() {
		return :ENTITY_LOWER:Service;
	}

}

TemplateService

public interface :ENTITY:Service extends Service<:ENTITY:> {

}

TemplateServiceImpl

@Service
public class :ENTITY:ServiceImpl extends AbstractService<:ENTITY:> implements :ENTITY:Service {

	@Autowired
	private :ENTITY:Repository :ENTITY_LOWER:Repository;
	
	@Override
	public JpaRepository<:ENTITY:, Long> getRepository() {
		return :ENTITY_LOWER:Repository;
	}
	
}

With this simple class you can create automatic files in your project structure, this files i used in Gist, represent a simple architecture of a project Spring Framework, however it is possible adapt in other project, as in a Android project or in a Angular aplication.

You only have to create the Template files, in template file you can use two variables :ENTITY: and :ENTITY_LOWER:, during process these variabels will be replace by your Entity/Model name.

variable :ENTITY_LOWER: will convert the name model with first letter to lower case.

To end, use method getEntityFileTypeList() to add yours Template files, the method has three parameters: relativePath, type and template:

1. relativePath: location where will new file be save;
2. type: name of file with extension;
3. template: name of template file;

to create entity file only use the extension, for exemple .java.