SpringMVC获取前端数据的四种方法

喜欢ヅ旅行 2022-04-18 04:15 922阅读 0赞

> 在获取数据之前先说下注解，注解的功能大家都知道，不再多说，这里说下如何使用

首先，我们需要在springmvc-servlet.xml文件中添加

<mvc:annotation-driven/>
        
        <context:component-scan base-package="com.jie.controller"/>

下面介绍获取前端数据的几种方法

## 1.req.getParameter() ##

这个和servlet中的使用一样

@RequestMapping("/login")
        public ModelAndView login(HttpServletRequest req, HttpServletResponse resp){
            String userName=req.getParameter("n");
            String userPwd=req.getParameter("p");
            UserService service=new UserService();
            boolean r=service.isLogin(userName,userPwd);
            ModelAndView mv=null;
            if (r) {
                System.out.println("登录成功！");
                mv=new ModelAndView("list");
                mv.addObject("msg","登录成功");
            }else {
                System.out.println("登录失败！");
                mv=new ModelAndView("index");
                mv.addObject("msg","登录失败");
            }
            return mv;
    }

service类

package com.jie.service;
    
    public class UserService {
    
        //登录
        public boolean isLogin(String userName,String userPwd){
            if (userName.equals("jie")&&userPwd.equals("123123"))
                return true;
            return false;
        }
    }

user类

package com.jie.dao;
    
    public class User {
        private int userId;
        private String userName;
        private String userPwd;
    
        public String getUserName() {
            return userName;
        }
    
        public void setUserName(String userName) {
            this.userName = userName;
        }
    
        public String getUserPwd() {
            return userPwd;
        }
    
        public void setUserPwd(String userPwd) {
            this.userPwd = userPwd;
        }
    
        public int getUserId() {
            return userId;
        }
    
        public void setUserId(int userId) {
            this.userId = userId;
        }
    
        public User() {
        }
    
        public User(String userName, String userPwd) {
            this.userName = userName;
            this.userPwd = userPwd;
        }
    }

前端的jsp页面直接使用el表达式接受数据就行，这里不再写

## 2.通过形参直接接收 ##

@RequestMapping("/login1")
        public ModelAndView login1(int userId,String userName,String userPwd){
            System.out.println(userId+"   "+userName+"  "+userPwd);
            return new ModelAndView("list");
        }

如果遇到前后端传值不同时使用@RequestParam()，例如：

@RequestMapping("/login11")
        public ModelAndView login11(@RequestParam("id") int userId, String userName, String userPwd){
            System.out.println(userId+"   "+userName+"  "+userPwd);
            return new ModelAndView("list");
        }

## 3.通过对象接收 ##

@RequestMapping("/login2")
        public ModelAndView login2(User user){
            ModelAndView mv=new ModelAndView("index");
            mv.addObject("user",user);
            return mv;
        }

## 4.地址栏传参 restful ##

@RequestMapping("/delete/{id}")
        public ModelAndView delete(@PathVariable("id") int userId){
            System.out.println(userId);
            return new ModelAndView("list");
        }

## 最后：解决中文乱码 ##

在web.xml文件中配置过滤器

<filter>
            <filter-name>characterEncoding</filter-name>
            <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
            <init-param>
                <param-name>encoding</param-name>
                <param-value>utf-8</param-value>
            </init-param>
        </filter>
        <filter-mapping>
            <filter-name>characterEncoding</filter-name>
            <url-pattern>/*</url-pattern>
        </filter-mapping>