Dodanie interfejsow

Mi sie taki kod bez problemu kompiluje:

public interface TestInterface {
	public Response addDocument(String fileName,
			String fileSignature,
			String filePath,
			File file,
			String endFile) throws Exception; 

}

public class DocumentsResource implements TestInterface {
	private Connection connect = null;
	private Statement statement = null;
	private PreparedStatement preparedStatement = null;
	private ResultSet resultSet = null;

	@Override
	@PUT
	@Consumes(MediaType.MULTIPART_FORM_DATA)
	@Produces(MediaType.APPLICATION_JSON)
	public Response addDocument(@FormDataParam("fileName") String fileName,
			@FormDataParam("fileSignature") String fileSignature,
			@FormDataParam("filePath") String filePath,
			@FormDataParam("file") File file,
			@FormDataParam("endFile") String endFile) throws Exception {
		try { ...