2022-08-20  阅读(627)

上节我们利用List集合来封装多个地址信息,其实把List集合换成Map集合也是可以的。下面,看看Spring MVC如何使用Map集合类型封装表单参数?

1 设计表单

            
            <%@ page contentType="text/html;charset=UTF-8" language="java" %>
            <html>
            <head>
                <title>一点教程网 - www.yiidian.com</title>
            </head>
            <body>
            <h2>Map集合类型参数封装</h2>
            <form action="/param.do" method="post">
                用户名:<input type="text" name="username"><br>
                年龄:<input type="text" name="age"><br>
                省份1:<input type="text" name="address['a1'].province"><br>
                城市1:<input type="text" name="address['a1'].city"><br>
                省份2:<input type="text" name="address['a2'].province"><br>
                城市2:<input type="text" name="address['a2'].city"><br>
                <input type="submit" value="提交">
            </form>
            </body>
            </html>

注意:这里的address['a1'].city,a1是赋值给Map的key,city是赋值给Address的city属性

2 设计Pojo

Address对象:

            
            package com.yiidian.domain;
            
            /**
             * 封装用户的地址信息
             * 一点教程网 - www.yiidian.com
             */
            public class Address {
                private String province;
                private String city;
            
                public String getProvince() {
                    return province;
                }
                public void setProvince(String province) {
                    this.province = province;
                }
                public String getCity() {
                    return city;
                }
                public void setCity(String city) {
                    this.city = city;
                }
            
                @Override
                public String toString() {
                    return "Address{" +
                            "province='" + province + '\'' +
                            ", city='" + city + '\'' +
                            '}';
                }
            }

User对象:

            
            package com.yiidian.domain;
            
            import java.util.List;
            import java.util.Map;
            
            /**
             * 用于封装表单数据
             * 一点教程网 - www.yiidian.com
             */
            public class User {
                private String username;
                private Integer age;
            
                private Map<String,Address> address;//这里使用Map集合接收表单多个地址信息
            
                public Map<String, Address> getAddress() {
                    return address;
                }
            
                public void setAddress(Map<String, Address> address) {
                    this.address = address;
                }
            
                public String getUsername() {
                    return username;
                }
            
                public void setUsername(String username) {
                    this.username = username;
                }
            
                public Integer getAge() {
                    return age;
                }
            
                public void setAge(Integer age) {
                    this.age = age;
                }
            
                @Override
                public String toString() {
                    return "User{" +
                            "username='" + username + '\'' +
                            ", age=" + age +
                            ", address=" + address +
                            '}';
                }
            
            }

在User对象使用Map集合来封装多个地址信息

3 编写Controller

            
            package com.yiidian.controller;
            import com.yiidian.domain.Address;
            import com.yiidian.domain.User;
            import org.springframework.stereotype.Controller;
            import org.springframework.web.bind.annotation.RequestMapping;
            
            import java.util.Map;
            
            /**
             * Map集合参数封装
             * 一点教程网 - www.yiidian.com
             */
            @Controller
            public class ParamController {
            
                @RequestMapping("/param.do")
                public String save(User user){
                    System.out.println("用户名:"+user.getUsername());
                    System.out.println("年龄:"+user.getAge());
                    //遍历所有地址信息
                    Map<String, Address> address = user.getAddress();
                    for(Map.Entry entry:address.entrySet()){
                        System.out.println(entry.getKey()+"--"+entry.getValue());
                    }
                    return "success";
                }
            }

4 springmvc.xml配置

            
            <?xml version="1.0" encoding="UTF-8"?>
            <beans xmlns="http://www.springframework.org/schema/beans"
                   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc"
                   xmlns:context="http://www.springframework.org/schema/context"
                   xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
            
                <!-- 1.扫描Controller的包-->
                <context:component-scan base-package="com.yiidian.controller"/>
            
                <!-- 2.配置视图解析器 -->
                <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
                    <!-- 2.1 页面前缀 -->
                    <property name="prefix" value="/pages/"/>
                    <!-- 2.2 页面后缀 -->
                    <property name="suffix" value=".jsp"/>
                </bean>
            
                <!-- 3.创建处理器适配器和处理器映射器-->
                <mvc:annotation-driven/>
            </beans>

5 运行测试

202202131334444821.png

控制台输出:

202202131334450812.png

源码下载:https://pan.baidu.com/s/1MqqrdwtcrCLVJUggRfMTeg

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