SpringMVC学习四、数据处理与乱码问题

数据处理

处理提交数据

1. 提交的域名称和处理方法的参数名一致

2. 提交的域名称和处理方法的参数名不一致

   @GetMapping("/t1")
       public String test1(@RequestParam("name1") String name, Model model) {
           //1.接收前端参数
           System.out.println("接收到前端的参数为：" + name);
           //2.将返回代结果传递给前端
           model.addAttribute("msg",name);
           //3.跳转视图
           return "test";
       }

3. 提交的是一个对象

       @GetMapping("/t2")
       public String test2(User user) {
           System.out.println(user);
           return "test";
       }

   http://localhost:8080/springmvc_03_servlet_war_exploded/user/t2?id=1&name=q&age=1

Model、ModelMap、ModeAndView的区别

• Model 只有个别方法，适合存储数据，简化
• ModelMap 继承了 LinkedMap，除了实现自身方法，还可以使用LinkedMap的方法与特性
• ModelAndView 可以在存储数据的同时，进行设置返回的逻辑视图，进行控制展示层的跳转

乱码问题

解决方案一、过滤器

public class EncodingFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        servletRequest.setCharacterEncoding("utf-8");
        servletResponse.setCharacterEncoding("utf-8");

        filterChain.doFilter(servletRequest,servletResponse);
    }

    @Override
    public void destroy() {

    }
}

<filter>
    <filter-name>encoding</filter-name>
    <filter-class>cn.imut.filter.EncodingFilter</filter-class>
</filter>

<filter-mapping>
    <filter-name>encoding</filter-name>
    <!-- 过滤所有的请求-->
    <url-pattern>/*</url-pattern>
</filter-mapping>

@Controller
public class EncodingController {

    //过滤器解决乱码
    @PostMapping("/e/t1")
    public String test1(String name, Model model) {
        model.addAttribute("msg",name);
        return "test";
    }
}

解决方案二、SpringMVC自带过滤器

<!-- springMVC自带过滤器-->
<filter>
    <filter-name>encoding</filter-name>
    <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>

    <init-param>
        <param-name>eccoding</param-name>
        <param-value>utf-8</param-value>
    </init-param>
</filter>
<filter-mapping>
    <filter-name>encoding</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>