java - 如何在 Web 应用程序项目的 Controller 中将字符串作为 JSON 对象返回

Question

所以我有这个 Controller

    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";
    }


}

函数设置表单返回“brands”，该“brands”又映射到 Spring Servlet 中的 brands.jsp。我想返回解决方案的 JSON 对象而不是整个 JSP 页面。

我怎样才能做到这一点？任何形式的帮助将不胜感激。

Answer 1

由于您要将结果数据添加到 map 中，因此将返回类型设置为 Map<String, Object>并用 @ResposeBody 进行注释正如 @jb nizet 评论的那样，

@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;
}