ssm整合（spring，springmvc，mybatis），实现一对多查询

谁践踏了优雅 2022-04-05 11:22 423阅读 0赞

**第一步：导包（由于包太多，这里就不一一介绍），整个工程目录如下：**  
![在这里插入图片描述][20181212100421404.jpg]  
**第二步：创建两张表（本人两张表分别为users和orders），如下图所示：**  
users表：  
![在这里插入图片描述][20181212110750450.jpg]  
orders表：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQzMjU0NDg4_size_16_color_FFFFFF_t_70]  
**第三步：将ssm框架搭起来（spring主配置文件，mybatis主配置文件，springmvc的web.xml配置文件与xxx-servlet.xml配置文件）：**  
web.xml配置文件：

<?xml version="1.0" encoding="UTF-8"?>
    <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
      <display-name>SSM</display-name>
      <welcome-file-list>
        <welcome-file>index.html</welcome-file>
        <welcome-file>index.htm</welcome-file>
        <welcome-file>index.jsp</welcome-file>
        <welcome-file>default.html</welcome-file>
        <welcome-file>default.htm</welcome-file>
        <welcome-file>default.jsp</welcome-file>
      </welcome-file-list>
      
      
    	<filter>
    		<filter-name>encodingFilter</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>
    		
    		<init-param>
    			<param-name>forceRequestEncoding</param-name>
    			<param-value>true</param-value>	
    		</init-param>
    		
    		<init-param>
    			<param-name>forceResponseEncoding</param-name>
    			<param-value>true</param-value>
    		</init-param>
    	</filter>
    	
    	<filter-mapping>
    		<filter-name>encodingFilter</filter-name>
    		<url-pattern>/*</url-pattern>
    	</filter-mapping>
    	
      
    	<servlet>
    		<servlet-name>springmvc</servlet-name>
    		
    		<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    		<load-on-startup>1</load-on-startup>
    	</servlet>
    
    	<servlet-mapping>
    		<servlet-name>springmvc</servlet-name>
    		
    		<url-pattern>/</url-pattern>
    		
    	</servlet-mapping>
    	
    	
    	<context-param>
    		<param-name>contextConfigLocation</param-name>
    		<param-value>classpath*:config/applicationContext.xml</param-value>
    		
    	</context-param>
    	<listener>
    		<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    	</listener>
     
    </web-app>

applicationContext.xml（spring主配置文件）：

<?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:aop="http://www.springframework.org/schema/aop"
    	xmlns:context="http://www.springframework.org/schema/context"
    	xmlns:jdbc="http://www.springframework.org/schema/jdbc"
    	xmlns:jee="http://www.springframework.org/schema/jee"
    	xmlns:lang="http://www.springframework.org/schema/lang"
    	xmlns:mvc="http://www.springframework.org/schema/mvc"
    	xmlns:oxm="http://www.springframework.org/schema/oxm"
    	xmlns:p="http://www.springframework.org/schema/p"
    	xmlns:task="http://www.springframework.org/schema/task"
    	xmlns:tx="http://www.springframework.org/schema/tx"
    	xmlns:util="http://www.springframework.org/schema/util"
    	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
    		http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
    		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
    		http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.0.xsd
    		http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.0.xsd
    		http://www.springframework.org/schema/lang http://www.springframework.org/schema/lang/spring-lang-3.0.xsd
    		http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
    		http://www.springframework.org/schema/oxm http://www.springframework.org/schema/oxm/spring-oxm-3.0.xsd
    		http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-3.0.xsd
    		http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
    		http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.0.xsd">
    
    
    	
    	<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
    		<property name="driverClassName" value="com.mysql.jdbc.Driver"></property>
    		<property name="url" value="jdbc:mysql://localhost:3306/ssm"></property>
    		<property name="username" value="root"></property>
    		<property name="password" value="1234"></property>
    	</bean>
    	
    	
    	<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    		<property name="dataSource" ref="dataSource"></property>
    	</bean>
    	
    	
    	<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
    		<property name="dataSource" ref="dataSource"></property>
    		
    		<property name="configLocation" value="classpath:config/config.xml"></property>
    		
    		
    		<property name="mapperLocations" value="classpath*:com/zhiyuan/frank/mapper/*.xml"></property>
    		
    		
    	</bean>
    	
    		
    	<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
    		<property name="basePackage" value="com.zhiyuan.frank.mapper"></property>
    	</bean>
    </beans>

config.xml（mybatis主配置文件）：

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE configuration PUBLIC "mybatis-3-config" "mybatis-3-config.dtd" >
    <configuration>
    	
    	<typeAliases>
    		<package name="com.zhiyuan.frank.pojo"/>
    	</typeAliases>
    </configuration>

springmvc-servlet.xml（配置文件）：

框架搭好之后可以运行一下，如果没有报错信息，则代表框架搭建成功  
**第四步：创建改表相对应的实体类：**  
推荐类与表名同名（类命名规范：类名首字母大写）  
Users类：

package com.zhiyuan.frank.pojo;
    
    import java.util.List;
    
    public class Users {
    	private int uId;
    	private String username;
    	private String mobile;
    	private List<Orders> orders;
    	public List<Orders> getOrders() {
    		return orders;
    	}
    	public void setOrders(List<Orders> orders) {
    		this.orders = orders;
    	}
    	public int getuId() {
    		return uId;
    	}
    	public void setuId(int uId) {
    		this.uId = uId;
    	}
    	public String getUsername() {
    		return username;
    	}
    	public void setUsername(String username) {
    		this.username = username;
    	}
    	public String getMobile() {
    		return mobile;
    	}
    	public void setMobile(String mobile) {
    		this.mobile = mobile;
    	}
    }

Orders类：

package com.zhiyuan.frank.pojo;
    
    public class Orders {
    	private int orderId;
    	private int usersId;
    	private String productName;
    	private String orderNo;
    	private double money;
    	private Users users;
    	public Users getUsers() {
    		return users;
    	}
    	public void setUsers(Users users) {
    		this.users = users;
    	}
    	public int getOrderId() {
    		return orderId;
    	}
    	public void setOrderId(int orderId) {
    		this.orderId = orderId;
    	}
    	public int getUsersId() {
    		return usersId;
    	}
    	public void setUsersId(int usersId) {
    		this.usersId = usersId;
    	}
    	public String getProductName() {
    		return productName;
    	}
    	public void setProductName(String productName) {
    		this.productName = productName;
    	}
    	public String getOrderNo() {
    		return orderNo;
    	}
    	public void setOrderNo(String orderNo) {
    		this.orderNo = orderNo;
    	}
    	public double getMoney() {
    		return money;
    	}
    	public void setMoney(double money) {
    		this.money = money;
    	}
    }

**第五步：编写index.jsp页面：**

<%@ page language="java" import="java.util.*"
        pageEncoding="UTF-8"%>
    
    <%
    	String basepath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+request.getContextPath()+"/";
    	//一种获取页面的方式
    %>
    
    <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>获取页面</title>
    </head>
    <body>
    	<h1><a href="users">获取用户所有订单</a></h1>
    	<h1><%=basepath %></h1>
    </body>
    </html>

**第六步：编写UsersController.java页面：**

package com.zhiyuan.frank.controller;
    /**
     * 该类指的是SpringMVC中的C，代表控制器，业务的逻辑都写在该类中
     */
    import java.util.List;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.servlet.ModelAndView;
    
    import com.zhiyuan.frank.mapper.Userslist;
    import com.zhiyuan.frank.pojo.*;
    
    @Controller
    //@Controller 用于标记在一个类上，通俗来说，被Controller标记的类就是一个控制器，这个类中的方法，就是相应的动作。
    @RequestMapping("/users")//users与index中a标签中href属性保持一致
    //@RequestMapping是一个用来处理请求地址映射的注解，可用于类或方法上。用于类上，表示类中的所有响应请求的方法都是以该地址作为父路径。
    public class UsersController {
    	@Autowired
    	//@Autowired注解是按照类型（byType）装配依赖对象，默认情况下它要求依赖对象必须存在，如果允许null值，可以设置它的required属性为false
    	Userslist list;
    	
    	@RequestMapping
    	public ModelAndView firstssm(){
    		ModelAndView mav = new ModelAndView("order_form");//"order_form":是返回页面的名字
    		//实例化一个ModelAndView对象
    		Users users = list.GetUsersID(1);
    		//调用接口层的方法并传入参数
    		List<Orders> list = users.getOrders();
    		mav.addObject("users",list);//"user":键,list:值(这里的值是接口层查询完后返回的值)
    		mav.addObject("username",users.getUsername());
    		//把查询结果封装到模型视图里面
    		return mav;
    	}
    }

**第七步：编写Userslist.java接口：**

package com.zhiyuan.frank.mapper;
    
    import com.zhiyuan.frank.pojo.Users;
    
    public interface Userslist {
    	public Users GetUsersID(int id);
    	//这里的接口名要与mapper.xml中的select中id保持一致
    }

**第八步：编写usersmapper.xml配置文件：**

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE mapper PUBLIC "mybatis-3-mapper" "mybatis-3-mapper.dtd" >
    <mapper namespace="com.zhiyuan.frank.mapper.Userslist">
    
    	<resultMap type="users" id="MaMap">
    		<result property="uId" column="u_id"/>
    		<result property="username" column="username"/>
    		<result property="mobile" column="mobile"/>
    		<collection property="orders" ofType="orders" column="users_id">
    		
    			<result property="orderId" column="order_id"/>
    			<result property="usersId" column="users_id"/>
    			<result property="productName" column="product_name"/>
    			<result property="orderNo" column="order_no"/>
    			<result property="money" column="money"/>
    		</collection>
    	</resultMap>
    
    	<select id="GetUsersID" parameterType="int" resultMap="MaMap">
    		select * from users,orders where users.u_id = orders.users_id and users.u_id=#{id}
    	</select>
    </mapper>

**第九步：编写order\_form.jsp返回jsp页面：**

<%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
    
    <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>查询结果页面</title>
    </head>
    <body>
    	
    	<table border="5" bordercolor="blue">
    	
    	<tr>
    		<td colspan="3">用户名:${username }</td>
    		
    	</tr>
    	<tr>
    		<td>商品名称</td>
    		<td>订单号</td>
    		<td>订单总额</td>
    		
    		<c:forEach items="${users}" var="orders">
    		
    			<tr>
    				<td>${orders.productName }</td>
    				<td>${orders.orderNo }</td>
    				<td>${orders.money }</td>
    			</tr>
    		</c:forEach>
    	</tr>
    	</table>
    </body>
    </html>

**运行结果，如下图所示：**  
index.jsp页面：  
![在这里插入图片描述][20181212114147371.jpg]  
order\_form.jsp返回结果页面：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQzMjU0NDg4_size_16_color_FFFFFF_t_70 1]

[20181212100421404.jpg]: /images/20220405/6c17c9e2b0b24a18b71545346bf5835f.png
[20181212110750450.jpg]: /images/20220405/8aeed9dffd2c446f8100c0a48970c246.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQzMjU0NDg4_size_16_color_FFFFFF_t_70]: /images/20220405/ddea863067e943d197885e55ab713692.png
[20181212114147371.jpg]: /images/20220405/429024ab3c014da1be756fb6b53ebd7f.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQzMjU0NDg4_size_16_color_FFFFFF_t_70 1]: /images/20220405/95c1ea3195964f9a84eab316941e76c9.png