CODEWITHSUNDEEP
javaspringannotations
n99
n99

Reputation: 41

@ModelAttribute annotated method WITH @ModelAttribute in method signature

I was wondering if it is possible to chain @ModelAttribute methods by having an @ModelAttribute annotated, but not request mapped, method use another ModelAttribute in the method signature. This would be in a controller.

ie

@ModelAttribute("attrOne")
public AttrOne getAttrOne() {
    return service.getAttOne();
}

@ModelAttribute("attrTwo")
public AttrTwo getAttrTwo(@ModelAttribute("attrOne") AttrOne attrOne){
    return anotherservice.getAttrTwo(attrOne);      
}

Then if there was a request mapped method that did this:

@RequestMapping(method=RequestMethod.GET)
public String doSomething(@ModelAttribute("attrTwo") AttrTwo attrTwo )

would this work?

I seem to get a null object for AttrOne in the second annotated method... as the first annotated method is not called by the second one...

Cheers

Upvotes: 4

Views: 1298

Answers (2)

Anton
Anton

Reputation: 1638

According to SPR-6299, this will be possible in Spring 4.1 RC1 or later.

Upvotes: 1

Markus Malkusch
Markus Malkusch

Reputation: 7868

I ran into the same situation by learning from the spring documention:

@ModelAttribute is also used at the method level [..]. For this usage the method signature can contain the same types as documented above for the @RequestMapping annotation.

I found SPR-6299 which faces this problem. In the comments you can find a workaround by providing only one @ModelAttribute annotated method which sets the attributes into the model:

@ModelAttribute
public void populateModel(Model model) { 
  model.addAttribute("attrOne", getAttrOne());
  model.addAttribute("attrTwo", getAttrTwo());
}

Upvotes: 4

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