How to nest @PathVariable in spring-rest?

Question

I have a simple @RestController service that takes query parameters, and spring automatically parses them to an bean:

@ResponseStatus(HttpStatus.OK)
@RequestMapping(value = "/rest", method = RequestMethod.GET)
public MyDTO getGiataHotel(@Valid MyParams p) {
    Sysout(p.getId()); //prints "123"
}

public class MyParams {
    private int id;
    //private SubParams subs;
}

Query: .../rest?id=123

Now I'd like to structure the parameter object with nested classes. How can I achieve this?

public class SubParams {
   private String name;
   //some more
}

Ideally my query should be: Query: .../rest?id=123&name=test, and the "test" string should go into the SubParams bean.

Is that possible?

`test` is a value. The parameter name is `name`. So, your SubParams has a field `name`? — Raffaele, Sep 01 '15 at 08:57
As you see above, yes the class `SubParams` has a field `name`. — membersound, Sep 01 '15 at 09:02
It would help a lot because to instantiate an inner class you must have the reference to the outer instance. A nested class can be safely extracted in its own file. But is there a dependency between the two? I still have not understood what's your purpose and what are your constraints — Raffaele, Sep 01 '15 at 10:04
I want spring to automatically move some of the get-query params automatically into the `SubParams`. I then could use eg `p.getSubParams()` to pass around only some fields that are grouped logically together. — membersound, Sep 01 '15 at 11:13
Then why don't you simply code .getSubParams() yourself? Why do you need Spring binding fields? Just create a new object manually copy fields — Raffaele, Sep 02 '15 at 06:46
Of course I could, but the question was: is spring capable of doing thisitselves? — membersound, Sep 02 '15 at 07:04

Karthik R · Answer 1 · 2015-09-01T09:10:29.707

You have to register a Custom Covertor if you need to set to a inner class. The change would be following:

@ResponseStatus(HttpStatus.OK)
@RequestMapping(value = "/rest", method = RequestMethod.GET)
public MyDTO getGiataHotel(@ModelAttribute("subParam") MyParams params, @Valid MyParams p) {
    //Do stuff
}

The subParam denotes that there is a converter registered for conversion.

public class MyParamsConverter implements Converter<String, MyParams> {

    @Override
    public MyParams convert(String name) {
        MyParams myParams = new MyParams();
        SubParams subParams = new SubParams();
        subParams.setName(name);
        myParams.setSubParams(subParams);
        return myParams;
    }

}

score 0 · Answer 2 · answered Sep 01 '15 at 08:47

You can achieve this by using the @ModelAttribute annotation : http://docs.spring.io/spring/docs/3.1.x/spring-framework-reference/html/mvc.html#mvc-ann-modelattrib-method-args (this is not in the Path parameters, but in the requestParams either get/post)

@RequestMapping(value="/owners/{ownerId}/pets/{petId}/edit", method =   RequestMethod.POST)
public String processSubmit(@ModelAttribute("pet") Pet pet, BindingResult result) {

     if (result.hasErrors()) {
         return "petForm";
     } 

     // ...       

}

But I want to use a `GET` query, not a post! – membersound Sep 01 '15 at 09:02 — membersound, Sep 01 '15 at 09:02

JJ_Jacob · Answer 3 · 2015-09-01T11:48:01.033

0

maybe u should use RequestMethod.POST, like this

@RequestMapping(value = "/rest", method =   RequestMethod.POST)
public ModelAndView getGiataHotel(@ModelAttribute("subparams") SubParams subparams){
      SubParams sub=subparams;
      //do something...
}

edited Sep 01 '15 at 11:48

answered Sep 01 '15 at 09:06

JJ_Jacob

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6

How to nest @PathVariable in spring-rest?

3 Answers3