Spring MVC - Multiple submit button to a Form

Question

I am trying to have 2 submit buttons post to a form, with each button action mapped to different controllers. Here are my mappings

@RequestMapping(value="/save", method=RequestMethod.POST, params="save")
@RequestMapping(value="/save", method=RequestMethod.POST, params="renew")

And my submit buttons look like these -

<input type="submit" name="save" class="button" value="Save" />
<input type="submit" name="renew" class="button" value="Renew" />

As you can see from my mapping, I am relying on the use of params to differentiate what button was clicked on. The problem is that it works 90% of the time but sometimes I get the exception below -

java.lang.IllegalStateException: Ambiguous handler methods mapped for HTTP path 'http://localhost:8090/myapp/save': {public java.lang.String com.myapp.SaveController.save(MyEntity,javax.servlet.http.HttpSession), public java.lang.String com.myapp.SaveController.saveAndRenew(MyEntity,javax.servlet.http.HttpSession)}
org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.lookupHandlerMethod(AbstractHandlerMethodMapping.java:248)
org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.getHandlerInternal(AbstractHandlerMethodMapping.java:194)

Strangely, when this happens and I re-submit the page, everything works fine afterwards. Is there a better way to achieve what I'm trying to do ?

Thanks!

Answer 1

if the form has these buttons specified:

input type="submit" class="button" name="save" value="Save"
input type="submit" class="button" name="delete" value="Delete"
input type="submit" class="button" name="cancel" value="Cancel"

you may direct to different url request according to button pressed with one controller.

for cancel button,

@RequestMapping(params = "cancel", method = RequestMethod.POST)
public String cancelUpdateUser(HttpServletRequest request) {
    return "redirect:/users.html";
}

what request mapping does is to scan post request if it contains params name = cancel.

for save button,

@RequestMapping(params = "save", method = RequestMethod.POST)
public String saveUser(HttpServletRequest request, @ModelAttribute User user, BindingResult result, SessionStatus status) {
    // validate your result
    // if no errors, save it and redirect to successView.
}

Answer 2

Why not:

<input type="submit" name="action" value="save" />

and then:

@RequestMapping(value="/save", method=RequestMethod.POST)
public String handlePost(@RequestParam String action){

    if( action.equals("save") ){
       //handle save
    }
    else if( action.equals("renew") ){
       //handle renew
    }

} 

Answer 3

If You have more controller methods with the same @RequestMapping that differs only in params attribute, You have to explicitly write:

• which parameter is supposed to be present in the request, e.g. params="save"
• which parameter is NOT supposed to be present in the request, e.g. params="!save"

In Your case:

@RequestMapping(value="/save", method=RequestMethod.POST, params={"save", "!renew"})
@RequestMapping(value="/save", method=RequestMethod.POST, params={"renew", "!save"})

This should fix error Ambiguous handler methods mapped for HTTP path ...

See Spring Web API 4.0.x - RequestMapping#params

Answer 4

Just create one controller with a method similar to this

@RequestMapping(value="/save", method=RequestMethod.POST)
public String handlePost(@RequestParam(required=false , value = "save") String saveFlag , @RequestParam(required=false , value = "renew") String renewFlag){

if(saveFlag != null{
   //handle save
}
else if(renewFlag !=null{
   //handle renew
}

}