SpringMVC学习

    junit
    junit
    4.12



    org.springframework
    spring-webmvc
    5.3.9



    javax.servlet
    servlet-api
    2.5


    javax.servlet.jsp
    jsp-api
    2.1


    javax.servlet
    jstl
    1.2

    
        SpringMVC
        org.springframework.web.servlet.DispatcherServlet

        
            contextConfigLocation
            classpath:springmvc-servlet.xml
        

        1
    

//    真实访问地址/HelloController/hello
    @RequestMapping("hello")
    public String hello(Model model) {
        model.addAttribute("msg","helloSpringMVC");
        //web-inf/jsp/hello.jsp
        return "hello";
    }
}

1. 后端代码

    @RequestMapping("Param/p1")
       public String p1(@RequestParam("a") int a, @RequestParam("b") int b, Model model) {
           int result = a + b;
           model.addAttribute("msg","结果是："+result);
           return "hello";
       }
   

2. 测试:http://127.0.0.1:8080/Param/p1?a=1&b=2

@GetMapping("Param/p1")
    public String p1(int a, int b, Model model) {
        int result = a + b;
        model.addAttribute("msg","结果是："+result);
        return "hello";
    }
@PostMapping("Param/p1")
public String p2(int a, int b, Model model) {
    int result = a + b;
    model.addAttribute("msg","结果是："+result);
    return "hello";
}

 @GetMapping("update")
    public String Update(User user) {
        System.out.println(user);
        return "test02";
    }

@GetMapping("Param/p1/{a}/{b}")
public String p1(@PathVariable int a, @PathVariable int b, Model model) {
    int result = a + b;
    model.addAttribute("msg","结果是："+result);
    return "hello";
}

• 测试：http://127.0.0.1:8080/Param/p1/1/2

• 默认方式

  return "hello";
  

• forward

  return "forward:hello";
  

• “redirect:/具体路径”

   return "redirect:/WEB-INF/jsp/test02.jsp";
  

1. 配置maven

           
               com.fasterxml.jackson.core
               jackson-databind
               2.13.0
           
   

2. 解决json return 乱码问题

   • 在springmvc-servlet.xml下

3. 创建工具类

   • JsonUtil

     public class JsonUtil {
         public static String setJson(Object o) {
             return setJson(o,"yyyy-MM-dd HH:mm:ss");
         }
         public static String setJson(Object o,String form) {
             ObjectMapper mapper = new ObjectMapper();
             mapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
             SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
             mapper.setDateFormat(simpleDateFormat);
             try {
                 String s = mapper.writevalueAsString(o);
                 return s;
             } catch (JsonProcessingException e) {
                 e.printStackTrace();
             }
             return null;
         }
     }
     
     

4. 使用

       @RequestMapping(value = "/j1")
   //    使方法不经过视图解析器
   //    @RequestBody
       public String json1() {
           User user = new User("吕竟", "男");
           return JsonUtil.setJson(user);
       }
   
       @RequestMapping("/j2")
       public String json2() {
           List list = new ArrayList();
           User user = new User("吕竟", "nv");
           User user1 = new User("吕竟", "nv");
           User user2 = new User("吕竟", "nv");
           list.add(user);
           list.add(user1);
           list.add(user2);
           return JsonUtil.setJson(list);
       }
   
       @RequestMapping("/j3")
       public String json3() {
           Date date = new Date();
           return JsonUtil.setJson(date);
       }