JavaWeb学习笔记（十一）：SpringMVC数据响应

• 前面学习了SpringMvc项目的简单搭建
• 今天天学springmvc的数据响应
  - 代码地址

//直接返回jsp页面方式
    @RequestMapping("/s1")
    public String show() {

        return "hello";
    }

//模型和视图返回
    @RequestMapping("/s2")
    public ModelAndView show2(){
        ModelAndView modelAndView = new ModelAndView();
        modelAndView.setViewName("hello");
        modelAndView.addObject("username","xiaoming");
        return  modelAndView;
    }

//模型和视图注入返回
    @RequestMapping("/s3")
    public ModelAndView show3(ModelAndView modelAndView){
        modelAndView.setViewName("hello");
        modelAndView.addObject("username","xiaogang");
        return  modelAndView;
    }

 //模型返回
    @RequestMapping("/s4")
    public String show4(Model model){
        model.addAttribute("username","xiaohong");
        return  "hello";
    }

 //request 方式返回
    @RequestMapping("/s5")
    public String show5(HttpServletRequest request){
        request.setAttribute("username","xiaoxu");
        return "hello";
    }

//response返回数据
    @RequestMapping("/s6")
    public void show6(HttpServletResponse response) throws IOException {
        response.getWriter().print("Hello World");
    }

 //直接返回字符串非模板
    @RequestMapping("/s7")
    @ResponseBody
    public String show7(){
        return  "xiaoming";
    }

//直接json数据
    @RequestMapping("/s8")
    @ResponseBody
    public String show8(){
        return "{"username":"zhangsan","age":18}";
    }

• 在pom.xml导入json包坐标

            com.fasterxml.jackson.core
            jackson-core
            2.9.0
        
        
            com.fasterxml.jackson.core
            jackson-databind
            2.9.0
        
        
            com.fasterxml.jackson.core
            jackson-annotations
            2.9.0
        

 //使用json包对象转json
    @RequestMapping("/s9")
    @ResponseBody
    public String show9() throws JsonProcessingException {
        User user = new User();
        user.setUsername("xiaoming");
        user.setAge(23);

        ObjectMapper objectMapper = new ObjectMapper();
        String json = objectMapper.writevalueAsString(user);
        return json;
    }

• 在spring-mvc.xml中配置处理器映射器

//spring容器返回对象集合
    @RequestMapping("/s10")
    @ResponseBody
    public User show10() {
        User user = new User();
        user.setUsername("xiaohong");
        user.setAge(23);
        return user;
    }

• 在xml文件我们可以配置mvc注解驱动，可以默认去使用json包，不再去配置