service-layer

I am in the process of determining a fairly simple layered architecture for a .NET MVC application that has a repository layer and a service layer. I have found some fairly clear and simple examples, notably www.asp.net , and some questions and answers here, but I am looking for something that is a little simpler, suitable for small applications, but that uses different projects, to get the idea across. The example I linked to above has the repository and service as classes in the Models namespace. That just isn't enough of a clear separation for me to be able to illustrate it properly. I have

I have some model class public class Account { @Email private String email; @NotNull private String rule; } and spring-validator public class AccountValidator implements Validator { @Override public boolean supports(Class aClass) { return Account.class.equals(aClass); } @Override public void validate(Object obj, Errors errors) { Account account = (Account) obj; ValidationUtils.rejectIfEmpty(errors, "email", "email.required"); ValidationUtils.rejectIfEmpty(errors, "rule", "rule.required"); complexValidateRule(account.getRule(), errors); } private void complexValidateRule(String rule, Errors

I work on a project with a legacy service layer that returns null in many places if a requested record does not exist, or cannot be accessed due to the caller not being authorized. I am talking about specific records requested by ID. For instance, something like: UserService.get(userId); I have recently pushed to have this API changed, or supplemented with a new API that throws exceptions instead. The debate over checked vs unchecked exceptions has ensued. Taking a note from the designers of JPA/Hibernate et all., I have suggested that unchecked exceptions may be most appropriate. My argument

I currently have a service layer based on the article Validating with a service layer from the ASP.NET site. According to this answer, this is a bad approach because the service logic is mixed with the validation logic which violates the single responsibility principle. I really like the alternative that is supplied but during re-factoring of my code I have come across a problem that I am unable to solve. Consider the following service interface: interface IPurchaseOrderService { void CreatePurchaseOrder(string partNumber, string supplierName); } with the following concrete implementation

Somewhat related to my other question Should raw Hibernate annotated POJO's be returned from the Data Access Layer, or Interfaces instead? , I am experienced in creation of nicely decoupled layers, but not using Hibernate or J2EE/JPA. I have been looking at documentation and tutorials, and am puzzled about how to use the EntityManger in an elegant way, as it seems it is responsible for both transactions (which I want to do at my service layer) and persistance methods (which I want to keep in the data access layer). Should I create it at the service layer and inject it into the data access

In an effort to understand MVC 2 and attempt to get my company to adopt it as a viable platform for future development, I have been doing a lot of reading lately. Having worked with ASP.NET pretty exclusively for the past few years, I had some catching up to do. Currently, I understand the repository pattern, models, controllers, data annotations, etc. But there is one thing that is keeping me from completely understanding enough to start work on a reference application. The first is the Service Layer Pattern. I have read many blog posts and questions here on Stack Overflow, but I still don't

Say you have an ASP.NET MVC project and are using a service layer, such as in this contact manager tutorial on the asp.net site: http://www.asp.net/mvc/tutorials/iteration-4-make-the-application-loosely-coupled-cs If you have viewmodels for your views, is the service layer the appropriate place to provide each viewmodel? For instance, in the service layer code sample there is a method public IEnumerable<Contact> ListContacts() { return _repository.ListContacts(); } If instead you wanted a IEnumerable, should it go in the service layer, or is there somewhere else that is the "correct" place?