How do i return a string as JSON Object Inthe controller of a web-app project

Question

so i have this controller as

    package org.aman.controller;
    import java.util.Map; 
    import org.springframework.beans.factory.annotation.Autowired;

        import org.springframework.stereotype.Controller;
        import org.springframework.validation.BindingResult;
        import org.springframework.web.bind.annotation.ModelAttribute;
        import org.springframework.web.bind.annotation.RequestMapping;
        import org.springframework.web.bind.annotation.RequestMethod;
        import org.springframework.web.bind.annotation.RequestParam;
        import org.aman.model.Brands;
        import org.aman.service.BrandsService;
        @Controller

    public class BrandsController {
        @Autowired
        private BrandsService brandsService;

    @RequestMapping("/index")
    public String setupForm(Map<String, Object> map) {
        Brands brands = new Brands();
        map.put("brands", brands);
        map.put("brandsList", brandsService.getAllBrands());
        return "brands";
    }
    @RequestMapping("/inde")
    public String setupFor(Map<String, Object> map) {
        Brands brands = new Brands();
        map.put("brands", brands);
        map.put("brandsSelectedList", brandsService.getAllBrands());
        return "query";
    }

    @RequestMapping(value = "/brands.do", method = RequestMethod.POST)
    public String doActions(@ModelAttribute Brands brands, BindingResult result, @RequestParam String action,
        Map<String, Object> map) {
        Brands brandsResult = new Brands();
        switch (action.toLowerCase()) {
        case "add":
            brandsService.add(brands);
            brandsResult = brands;
            break;
        case "edit":
            brandsService.edit(brands);
            brandsResult = brands;
            break;
        }
        map.put("brands", brandsResult);
        map.put("brandsList", brandsService.getAllBrands());
        return "brands";
    }


}

The function setup form returns "brands" which in turn maps to brands.jsp in the spring servlet. I want to return a JSON object of the solution instead of the whole JSP page.

How can I do that? Any kind of help will be appreciated.

Answer 1

Since you're adding your resultant data to a map make the return type as Map<String, Object> and annotate with @ResposeBody as @jb nizet commented,

@RequestMapping(value = "/brands.do", method = RequestMethod.POST)
public @ResponseBody Map<String, Object> map doActions(@ModelAttribute Brands brands, 
BindingResult result, @RequestParam String action, Map<String, Object> map) 
{
    Brands brandsResult = new Brands();
    switch (action.toLowerCase()) {
    case "add":
        brandsService.add(brands);
        brandsResult = brands;
        break;
    case "edit":
        brandsService.edit(brands);
        brandsResult = brands;
        break;
    }
    map.put("brands", brandsResult);
    map.put("brandsList", brandsService.getAllBrands());
    return map;
}