Spring controller, why is the returned view ignored?

Question

So, say I have an existing, working page Display Cashier, which displays information about a cashier in a shop. Now, I add a button to this page that looks like:

<a href="handleGetManager.ctl?cashierId=${id}" class="btn btn-mini">Manager</a>

The request-mapping for this URL maps it (successfully) to a controller: HandleGetManager

the HandleGetManager controller looks like this:

@Controller
public class HandleGetManager{

    private employeeBO employeeBO; //BO handles all business logic

    //spring hooks
    public HandleGetManager(){} 
    public void setemployeeBo(employeeBO employeeBO){
    this.employeeBO = employeeBO;
    }

    //get controller 
    @RequestMapping(method=RequestMethod.GET)
    public String getManager(@RequestParam String cashierId){

    Long managerId = employeeBO.getManagerByCashierId(cashierId); 

    String redirectUrl = "/displayManager.ctl?managerId=" + managerId.toString();
    return redirectUrl;
    }

}

Here's what happens when I try it:

I hit the new button on the Display Cashier page, I expect the following to happen:

• The browser sends a get request to the indicated URL

• The spring request-mapping ensures that the flow of control is passed to this class.

• the @RequestMapping(method=RequestMethod.GET) piece ensures that this method is evoked

• The @RequestParam String cashierId instructs Spring to parse the URL and pass the cashierId value into this method as a parameter.

• The EmployeeBo has been injected into the controller via spring.

• The Business logic takes place, envoking the BO and the managerId var is populated with the correct value.

• The method returns the name of a different view, with a new managerId URL arg appended

Now, up until this point, everything goes to plan. What I expect to happen next is:

• the browsers is directed to that URL

• whereupon it will send a get request to that url,

• the whole process will start again in another controller, with a different URL and a different URL arg.

instead what happens is:

• this controller returns the name of a different view

• The browser is redirected to a half-right, half wrong URL: handleGetManager.ctl?managerId=12345

• The URL argument changes, but the name of the controller does not, despite my explicitly returning it

• I get an error

What am I doing wrong? Have I missed something?

Answer 1

Assuming you have a UrlBasedViewResolver in your MVC configuration, the String value you return is a View name. The ViewResolver will take that name and try to resolve a View for it.

What you seem to want to do is to have a 301 response with a redirect. With view names, you do that by specifying a redirect: prefix in your view name. It's described in the documentation, here.

Here's a question/answer explaining all the (default) ways you can perform a redirect:

• How can I prevent Spring MVC from doing a redirect?