SpringMVC传值与取值

SpringMVC传值与取值

一、总共有4种方式传递值:

第一种:ModelAndvie

//1.modelAndView
@RequestMapping({"/index"})
public ModelAndView index(){
    //查询数据,获取所有的用户信息
    List<User> userItems = UserData.userItems;
    ModelAndView  mav=new ModelAndView();
    //设置数据(模型)
    mav.addObject("userItems",userItems);
    //设置视图名称
    mav.setViewName("index");
    return mav;
}

第二种:Model

//2.model
@RequestMapping("/index")
public String index(Model model){
    List<User> userItems = UserData.userItems;
    model.addAttribute("userItems",userItems);
    return "index";
}

第三种:ModelMap

@RequestMapping("index")
public String index(ModelMap modelMap){
    List<User> userItems = UserData.userItems;
    modelMap.addAttribute("userItems",userItems);
    return "index";
}

第四种:Map

 //4.Map
@RequestMapping("index")
 public String index(Map map){
     List<User> userItems = UserData.userItems;
     map.put("userItems",userItems);
     map.put("a","xiaoxiong");
     return "index";
 } 

二、取值的方式

第一种:直接取值

//如何取值
@RequestMapping("/del")
public String del(Integer id){
    System.out.println(id);
    List<User> userItems = UserData.userItems;
    for (User userItem : userItems) {
        if(userItem.getId()==id){
            userItems.remove(userItem);
            break;
        }
    }
    return "redirect:/index";
}

第二种:注释取值

@RequestMapping("/add")
//RequestParam 的三个参数 value表示name的字段名称required参数是否是必须的
public String add(Integer id,
                  @RequestParam(value = "userName",required = true,defaultValue = "小熊") String Name,
                  @RequestParam(value = "age",required = true,defaultValue = "22") Integer age,
                  @RequestParam(value = "email",required = true,defaultValue = "123@qq.com") String email,
                  @RequestParam(value = "address",required = true,defaultValue = "湖南长沙") String address){
    User user =new User(id,Name,age,email,address);
    UserData.userItems.add(user);
    //重定向到index进行所有的查询
    return "redirect:/index";
}

第三种:对象取值

@RequestMapping("/upd")
public String upd(User user){
    //怎么替换集合中的一个内容？
    List<User> userItems = UserData.userItems;
    for (User userItem : userItems) {
        if(userItem.getId()==user.getId()){
            BeanUtils.copyProperties(user,userItem);
        }
    }
    return "redirect:/index";
}

三、所有代码

1.com包下xiong包下controller包下类

package com.xiong.controller;


import com.xiong.dao.UserData;
import com.xiong.entity.User;
import org.springframework.beans.BeanUtils;
import org.springframework.stereotype.Controller;

import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;

import java.util.List;
import java.util.Map;

/**
 * 表示这是一个控制器的类
 */
@Controller
public class UserController {
    /**
     * 返回的是视图的名称,会被视图解析器进行解析
     */
//    @RequestMapping({"/ss","/index"})
//    public String index(){
//        //查询数据,获取所有的用户信息
//        List<User> userItems = UserData.userItems;
//        System.out.println("看看能笔不能进来");
//        return "index";
//    }

    //1.modelAndView
//    @RequestMapping({"/index"})
//    public ModelAndView index(){
//        //查询数据,获取所有的用户信息
//        List<User> userItems = UserData.userItems;
//        ModelAndView  mav=new ModelAndView();
//        //设置数据(模型)
//        mav.addObject("userItems",userItems);
//        //设置视图名称
//        mav.setViewName("index");
//        return mav;
//    }

//    //2.model
//    @RequestMapping("/index")
//    public String index(Model model){
//        List<User> userItems = UserData.userItems;
//        model.addAttribute("userItems",userItems);
//        return "index";
//    }

    //3.modelMap
//    @RequestMapping("index")
//    public String index(ModelMap modelMap){
//        List<User> userItems = UserData.userItems;
//        modelMap.addAttribute("userItems",userItems);
//        return "index";
//    }

    //4.Map
    @RequestMapping("index")
    public String index(Map map){
        List<User> userItems = UserData.userItems;
        map.put("userItems",userItems);
        map.put("a","xiaoxiong");
        return "index";
    }

    //如何取值
    @RequestMapping("/del")
    public String del(Integer id){
        System.out.println(id);
        List<User> userItems = UserData.userItems;
        for (User userItem : userItems) {
            if(userItem.getId()==id){
                userItems.remove(userItem);
                break;
            }
        }
        return "redirect:/index";
    }
    @RequestMapping("/edit")
    public String edit(Integer id, Model model){
        System.out.println(id);
        if(id!=null){
            //修改
            //通过id获取当前的对象
            List<User> userItems = UserData.userItems;
            for (User userItem : userItems) {
                if(userItem.getId()==id){
                    model.addAttribute("user",userItem);
                    break;
                }
            }
        }
        return "edit";
    }
    @RequestMapping("/add")
    //RequestParam 的三个参数 value表示name的字段名称required参数是否是必须的
    public String add(Integer id,
                      @RequestParam(value = "userName",required = true,defaultValue = "小熊") String Name,
                      @RequestParam(value = "age",required = true,defaultValue = "22") Integer age,
                      @RequestParam(value = "email",required = true,defaultValue = "123@qq.com") String email,
                      @RequestParam(value = "address",required = true,defaultValue = "湖南长沙") String address){
        User user =new User(id,Name,age,email,address);
        UserData.userItems.add(user);
        //重定向到index进行所有的查询
        return "redirect:/index";
    }
    @RequestMapping("/upd")
    public String upd(User user){
        //怎么替换集合中的一个内容？
        List<User> userItems = UserData.userItems;
        for (User userItem : userItems) {
            if(userItem.getId()==user.getId()){
                BeanUtils.copyProperties(user,userItem);
            }
        }
        return "redirect:/index";
    }
}

2.com包下xiong包下dao包下类

package com.xiong.dao;

import com.xiong.entity.User;

import java.util.ArrayList;
import java.util.List;

public class UserData {
    public static List<User> userItems = new ArrayList<>();

    /**
     * 静态代码块
     */
    static {
        userItems.add(new User(1, "张三", 18, "82372837@qqcom", "湖南长沙开福"));
        userItems.add(new User(2, "李四", 20, "82372837@qqcom", "湖南长沙岳麓"));
        userItems.add(new User(3, "王武", 30, "82372837@qqcom", "湖南长沙天心"));
        userItems.add(new User(4, "赵六", 23, "82372837@qqcom", "湖南长沙雨花"));
    }
}

3.com包下xiong包下entity包下类

package com.xiong.entity;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.extern.slf4j.Slf4j;

@Data
//有参构造函数
@AllArgsConstructor
//无参构造函数
@NoArgsConstructor
public class User {
    private Integer id;
    private String userName;
    private Integer age;
    private String  email;
    private String address;

}

4.resources包下application-context.xml文件

<?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:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd">

    <!--    扫包-->
    <context:component-scan base-package="com.xiong.controller"></context:component-scan>
    <!--    视图解析器-->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <!--        配置两个属性-->
        <!--        前缀-->
        <property name="prefix" value="/"></property>
        <!--        后缀-->
        <property name="suffix" value=".jsp"></property>
    </bean>
</beans>

5.webapp包下WEB-INF包下web.xml文件

<!DOCTYPE web-app PUBLIC
 "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
 "http://java.sun.com/dtd/web-app_2_3.dtd" >

<web-app>
  <display-name>Archetype Created Web Application</display-name>

    <!--    配置乱码过滤器-->
    <filter>
        <filter-name>characterEncodingFilter</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <!--       配置初始化参数,编码为UTF-8 -->
        <init-param>
            <param-name>encoding</param-name>
            <param-value>UTF-8</param-value>
        </init-param>
        <init-param>
            <param-name>forceEncoding</param-name>
            <param-value>true</param-value>
        </init-param>
    </filter>
    <!--    在servlet中也是有的-->
    <filter-mapping>
        <filter-name>characterEncodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

<!--    优先配置web.XML文件,目的是在程序启动的时候加载spring,springMVC的配置文件-->
<!--    加载springmvp的配置文件-->
 <servlet>
     <servlet-name>springmvc</servlet-name>
     <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
     <init-param>
         <param-name>contextConfigLocation</param-name>
         <param-value>classpath:application-context.xml</param-value>
     </init-param>
<!--     优先加载springmvc的配置文件-->
<!--     值越小,servlet的优先级越高,就越先被加载-->
     <load-on-startup>1</load-on-startup>
 </servlet>
    <servlet-mapping>
        <servlet-name>springmvc</servlet-name>
<!--        /*会拦截jsp /只会连接java类-->
        <url-pattern>/</url-pattern>
    </servlet-mapping>

</web-app>

6.webapp包下edit.jsp文件

<%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
    <form action="${user==null?'/add':'/upd'}">
        <p>编号:<input type="text" name="id" value="${user.id}"<c:if test="${user!=null}">readonly</c:if> ></p>
        <p>姓名:<input type="text" name="userName" value="${user.userName}"></p>
        <p>年龄:<input type="text" name="age" value="${user.age}"></p>
        <p>邮箱:<input type="text" name="email" value="${user.email}"></p>
        <p>地址:<input type="text" name="address" value="${user.address}"></p>
        <p><input type="submit" value="提交 "></p>
    </form>

</body>
</html>

7.webapp包下index.jsp文件

<%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<h1>${a}</h1>
<a href="/edit">新增</a>
    <table>
        <tr>
            <th>编号</th>
            <th>姓名</th>
            <th>年龄</th>
            <th>邮箱</th>
            <th>地址</th>
            <th>操作</th>
        </tr>
        <c:forEach items="${userItems}" var="user">
            <tr>
                <td>${user.id}</td>
                <td>${user.userName}</td>
                <td>${user.age}</td>
                <td>${user.email}</td>
                <td>${user.address}</td>
                <td>

                    <a href="/edit?id=${user.id}">修改</a>
                    <a href="del?id=${user.id}">删除</a>
                </td>
            </tr>

        </c:forEach>

    </table>
</body>
</html>

8.依赖

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <!--父工程-->
    <groupId>com.xiong</groupId>
    <artifactId>Mybatis-Study</artifactId>
    <packaging>pom</packaging>
    <version>1.0-SNAPSHOT</version>
    <modules>
        <module>mybatis-01</module>
        <module>mybatis-02</module>
        <module>mybatis-03</module>
        <module>mybatis-04</module>
        <module>mybatis-05</module>
        <module>mybatis-06</module>
        <module>mybatis-07</module>
        <module>mybatis-08</module>
<!--        解析XMl-->
        <module>analysisXml-09</module>
        <module>spring-01</module>
        <module>spring-02</module>
        <module>springAnnotation-03</module>
        <module>spring-aop-annotation</module>
        <module>gooverioc</module>
        <module>goaop</module>
        <module>spring-mybatis</module>
        <module>springmvc</module>
        <module>springmvc-02</module>

    </modules>
    <properties>
<!--        标签虽然可以随便命名但是尽量有意义-->
        <spring-varsion>5.1.3.RELEASE</spring-varsion>
    </properties>

    <!--导入依赖-->
    <dependencies>
    <!--mysql驱动-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.13</version>
        </dependency>
        <!--mybatis-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.2</version>
        </dependency>
        <!--        核心包spring-mybatis-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>1.3.2</version>
        </dependency>
        <!--        数据源,访问数据库通过数据源去访问-->
        <dependency>
            <groupId>commons-dbcp</groupId>
            <artifactId>commons-dbcp</artifactId>
            <version>1.4</version>
        </dependency>
        <!--junit-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>

        <!--        简化get set-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.18</version>
        </dependency>

        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>1.7.5</version>
        </dependency>
        <!--        log4j的日志打印-->
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>
        <!--   分页查询插件-->
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper</artifactId>
            <version>5.1.2</version>
        </dependency>
        <!--jdom -->
        <dependency>
            <groupId>org.jdom</groupId>
            <artifactId>jdom</artifactId>
            <version>1.1.3</version>
        </dependency>
        <!-- dom4j -->
        <dependency>
            <groupId>dom4j</groupId>
            <artifactId>dom4j</artifactId>
            <version>1.6.1</version>
        </dependency>
        <!--      日志文件-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.18</version>
        </dependency>
        <!--        jstl-->
        <dependency>
            <groupId>jstl</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>
        <!--        Servlet-->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
        </dependency>
        <!--        简化get set-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.16.22</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.3.5</version>
            <scope>compile</scope>
        </dependency>


        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.1.3.RELEASE</version>
        </dependency>


        <!--        这个是专用来实现切面的处理的包-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aspects</artifactId>
            <version>${spring-varsion}</version>
        </dependency>
    </dependencies>

<!-- 在build中配置resources,来防止我们资源导出失败的问题-->
    <build>
        <resources>
            <resource>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>true</filtering>
            </resource>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>true</filtering>
            </resource>
        </resources>
    </build>


</project>