Mybatis教程三(与Spring集成+整合SpringMVC)

Mybatis与Spring集成

前面讲到有关 mybatis 连接数据库,然后进行进行数据增删改查,以及多表联合查询的例子,但很多的项目中,通常会用 spring 这个粘合剂来管理 datasource 等。

整个Mybatis与Spring集成示例要完成的步骤如下:
1、示例功能描述
2、创建工程
3、数据库表结构及数据记录
4、实例对象
5、配置文件
6、测试执行,输出结果

1、示例功能描述
在本示例中,需要完成这样的一个简单功能,即,指定一个用户(ID=1),查询出这个用户的基本信息,并关联查询这个用户的所有订单。

2、创建工程
首先创建一个工程的名称为:mybatis07-spring,在 src 源代码目录下建立文件夹 config,并将原来的 mybatis 配置文件 Configuration.xml 移动到这个文件夹中, 并在 config 文家夹中建立 Spring 配置文件:applicationContext.xml。工程结构目录如下:
在这里插入图片描述
3、数据库表结构及数据记录
在本示例中,用到两个表:用户表和订单表,其结构和数据记录如下:

CREATE TABLE `user` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `username` varchar(64) NOT NULL DEFAULT '',
  `mobile` varchar(16) NOT NULL DEFAULT '',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of user
-- ----------------------------
INSERT INTO `user` VALUES ('1', 'yiibai', '13838009988');
INSERT INTO `user` VALUES ('2', 'saya', '13838009988');

订单表结构和数据如下:

CREATE TABLE `order` (
  `order_id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `user_id` int(10) unsigned NOT NULL DEFAULT '0',
  `order_no` varchar(16) NOT NULL DEFAULT '',
  `money` float(10,2) unsigned DEFAULT '0.00',
  PRIMARY KEY (`order_id`)
) ENGINE=InnoDB AUTO_INCREMENT=17 DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of order
-- ----------------------------
INSERT INTO `order` VALUES ('1', '1', '1509289090', '99.90');
INSERT INTO `order` VALUES ('2', '1', '1519289091', '290.80');
INSERT INTO `order` VALUES ('3', '1', '1509294321', '919.90');
INSERT INTO `order` VALUES ('4', '1', '1601232190', '329.90');
INSERT INTO `order` VALUES ('5', '1', '1503457384', '321.00');
INSERT INTO `order` VALUES ('6', '1', '1598572382', '342.00');
INSERT INTO `order` VALUES ('7', '1', '1500845727', '458.00');
INSERT INTO `order` VALUES ('8', '1', '1508458923', '1200.00');
INSERT INTO `order` VALUES ('9', '1', '1504538293', '2109.00');
INSERT INTO `order` VALUES ('10', '1', '1932428723', '5888.00');
INSERT INTO `order` VALUES ('11', '1', '2390423712', '3219.00');
INSERT INTO `order` VALUES ('12', '1', '4587923992', '123.00');
INSERT INTO `order` VALUES ('13', '1', '4095378812', '421.00');
INSERT INTO `order` VALUES ('14', '1', '9423890127', '678.00');
INSERT INTO `order` VALUES ('15', '1', '7859213249', '7689.00');
INSERT INTO `order` VALUES ('16', '1', '4598450230', '909.20');

4、实例对象
用户表和订单表分别对应两个实例对象,分别是:User.javaOrder.java,它们都在 com.yiibai.pojo 包中。
User.java代码内容如下:

package com.yiibai.pojo;

import java.util.List;

/** 
 * @describe: User
 * @author: Yiibai 
 * @version: V1.0
 * @copyright http://www.yiibai.com
 */  
public class User {
    
    
	private int id;
	private String username;
	private String mobile;
	
	public int getId() {
    
    
		return id;
	}
	public void setId(int id) {
    
    
		this.id = id;
	}
	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;
	}
	
}

Order.java代码内容如下:

package com.yiibai.pojo;

/**
 * @describe: Order - 订单
 * @author: Yiibai
 * @version: V1.0
 * @copyright http://www.yiibai.com
 */
public class Order {
    
    
	private int orderId;
	private String orderNo;
	private float money;
	private int userId;
	private User user;
	
	
	public int getUserId() {
    
    
		return userId;
	}
	public void setUserId(int userId) {
    
    
		this.userId = userId;
	}
	public int getOrderId() {
    
    
		return orderId;
	}
	public void setOrderId(int orderId) {
    
    
		this.orderId = orderId;
	}
	public User getUser() {
    
    
		return user;
	}
	public void setUser(User user) {
    
    
		this.user = user;
	}
	public String getOrderNo() {
    
    
		return orderNo;
	}
	public void setOrderNo(String orderNo) {
    
    
		this.orderNo = orderNo;
	}
	public float getMoney() {
    
    
		return money;
	}
	public void setMoney(float money) {
    
    
		this.money = money;
	}

}

5、配置文件
这个实例中有三个重要的配置文件,它们分别是:applicationContext.xmlConfiguration.xml 以及 UserMaper.xml
applicationContext.xml 配置文件里最主要的配置:

<?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:aop="http://www.springframework.org/schema/aop"
	xmlns:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context"
	xsi:schemaLocation="  
            http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.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/jee http://www.springframework.org/schema/jee/spring-jee-3.0.xsd  
            http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd"
	default-autowire="byName" default-lazy-init="false">
	
	<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
		<property name="driverClassName" value="com.mysql.jdbc.Driver" />
		<property name="url"
			value="jdbc:mysql://127.0.0.1:3306/yiibai?characterEncoding=utf8" />
		<property name="username" value="root" />
		<property name="password" value="" />
	</bean>

	<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
		<!--dataSource属性指定要用到的连接池-->
		<property name="dataSource" ref="dataSource" />
		<!--configLocation属性指定mybatis的核心配置文件-->
		<property name="configLocation" value="config/Configuration.xml" />
	</bean>

	<bean id="userMaper" class="org.mybatis.spring.mapper.MapperFactoryBean"> 
		<!--sqlSessionFactory属性指定要用到的SqlSessionFactory实例-->
		<property name="sqlSessionFactory" ref="sqlSessionFactory" />
		<!--mapperInterface属性指定映射器接口,用于实现此接口并生成映射器对象-->
		<property name="mapperInterface" value="com.yiibai.maper.UserMaper" />
	</bean>
</beans> 

配置文件 Configuration.xml 的内容如下:

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
	<typeAliases>
		<typeAlias alias="User" type="com.yiibai.pojo.User" />
		<typeAlias alias="Order" type="com.yiibai.pojo.Order" />
	</typeAliases>
	<!-- Mybatis和Spring 集成之后,这些可以完全删除(注释掉),数据库连接的管理交给 Spring 来管理 -->
	<!--
		<environments default="development"> <environment id="development">
		<transactionManager type="JDBC"/> <dataSource type="POOLED"> <property
		name="driver" value="com.mysql.jdbc.Driver"/> <property name="url"
		value="jdbc:mysql://127.0.0.1:3306/yiibai?characterEncoding=utf8" />
		<property name="username" value="root"/> <property name="password"
		value=""/> </dataSource> </environment> </environments>
	-->
	<mappers>
		<mapper resource="com/yiibai/maper/UserMaper.xml" />
	</mappers>
</configuration>

UserMaper.xml 用于定义查询和数据对象映射,其内容如下:

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" 
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.yiibai.maper.UserMaper">
	
		<!-- 为了返回list 类型而定义的returnMap -->
	<resultMap type="User" id="resultUser">
        <id column="id" property="id" />
        <result column="username" property="username" />
        <result column="mobile" property="mobile" />
    </resultMap>
    
	<!-- User 联合 Order 查询 方法的配置 (多对一的方式)  -->	
	<resultMap id="resultUserOrders" type="Order">
	    <id property="orderId" column="order_id" />
	    <result property="orderNo" column="order_no" />
	    <result property="money" column="money" />
	    <result property="userId" column="user_id" />
	    
	    <association property="user" javaType="User">
	        <id property="id" column="id" />
	        <result property="username" column="username" />
	        <result property="mobile" column="mobile" />	        
	    </association>	    
	</resultMap> 
	
	<select id="getUserOrders" parameterType="int" resultMap="resultUserOrders">
	   SELECT u.*,o.* FROM `user` u, `order` o 
	          WHERE u.id=o.user_id AND u.id=#{id}
	</select>
	
	<select id="getUserById" resultMap="resultUser" parameterType="int">
		SELECT *
		FROM user
		WHERE id=#{id}
	</select>    
</mapper>

6、测试执行,输出结果
Main.java:

import java.util.List;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.yiibai.maper.UserMaper;
import com.yiibai.pojo.Order;
import com.yiibai.pojo.User;

public class Main {
    
    

	private static ApplicationContext ctx;

	static {
    
    
		ctx = new ClassPathXmlApplicationContext(
				"config/applicationContext.xml");
	}

	public static void main(String[] args) {
    
    
		UserMaper userMaper = (UserMaper) ctx.getBean("userMaper");
		// 测试id=1的用户查询,可根据数据库中的情况修改.
		User user = userMaper.getUserById(1);
		System.out.println("获取用户 ID=1 的用户名:"+user.getUsername());

		// 得到文章列表测试
		System.out.println("得到用户id为1的所有订单列表:");
		System.out.println("=============================================");
		List<Order> orders = userMaper.getUserOrders(1);

		for (Order order : orders) {
    
    
			System.out.println("订单号:"+order.getOrderNo() + ",订单金额:" + order.getMoney());
		}
	}
}

运行结果如下:

log4j:WARN No appenders could be found for logger (org.springframework.context.support.ClassPathXmlApplicationContext).
log4j:WARN Please initialize the log4j system properly.
获取用户 ID=1 的用户名:yiibai
得到用户id为1的所有订单列表:
=============================================
订单号:1509289090,订单金额:99.9
订单号:1519289091,订单金额:290.8
订单号:1509294321,订单金额:919.9
订单号:1601232190,订单金额:329.9
订单号:1503457384,订单金额:321.0
订单号:1598572382,订单金额:342.0
订单号:1500845727,订单金额:458.0
订单号:1508458923,订单金额:1200.0
订单号:1504538293,订单金额:2109.0
订单号:1932428723,订单金额:5888.0
订单号:2390423712,订单金额:3219.0
订单号:4587923992,订单金额:123.0
订单号:4095378812,订单金额:421.0
订单号:9423890127,订单金额:678.0
订单号:7859213249,订单金额:7689.0
订单号:4598450230,订单金额:909.2

MyBatis整合Spring MVC

整个Mybatis与Spring MVC 示例要完成的步骤如下:
1、示例功能描述
2、创建工程
3、数据库表结构及数据记录
4、实例对象
5、配置文件
6、测试执行,输出结果

1、示例功能描述
在本示例中,需要使用 MyBatis和Spring MVC整合完成这样的一个简单功能,即指定一个用户(ID=1),查询出这个用户关联的所有订单。

2、创建工程
在这里插入图片描述
3、数据库表结构及数据记录
在本示例中,用到两个表:用户表和订单表,其结构和数据记录如下:

CREATE TABLE `user` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `username` varchar(64) NOT NULL DEFAULT '',
  `mobile` varchar(16) NOT NULL DEFAULT '',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of user
-- ----------------------------
INSERT INTO `user` VALUES ('1', 'yiibai', '13838009988');
INSERT INTO `user` VALUES ('2', 'saya', '13838009988');
CREATE TABLE `order` (
  `order_id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `user_id` int(10) unsigned NOT NULL DEFAULT '0',
  `order_no` varchar(16) NOT NULL DEFAULT '',
  `money` float(10,2) unsigned DEFAULT '0.00',
  PRIMARY KEY (`order_id`)
) ENGINE=InnoDB AUTO_INCREMENT=17 DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of order
-- ----------------------------
INSERT INTO `order` VALUES ('1', '1', '1509289090', '99.90');
INSERT INTO `order` VALUES ('2', '1', '1519289091', '290.80');
INSERT INTO `order` VALUES ('3', '1', '1509294321', '919.90');
INSERT INTO `order` VALUES ('4', '1', '1601232190', '329.90');
INSERT INTO `order` VALUES ('5', '1', '1503457384', '321.00');
INSERT INTO `order` VALUES ('6', '1', '1598572382', '342.00');
INSERT INTO `order` VALUES ('7', '1', '1500845727', '458.00');
INSERT INTO `order` VALUES ('8', '1', '1508458923', '1200.00');
INSERT INTO `order` VALUES ('9', '1', '1504538293', '2109.00');
INSERT INTO `order` VALUES ('10', '1', '1932428723', '5888.00');
INSERT INTO `order` VALUES ('11', '1', '2390423712', '3219.00');
INSERT INTO `order` VALUES ('12', '1', '4587923992', '123.00');
INSERT INTO `order` VALUES ('13', '1', '4095378812', '421.00');
INSERT INTO `order` VALUES ('14', '1', '9423890127', '678.00');
INSERT INTO `order` VALUES ('15', '1', '7859213249', '7689.00');
INSERT INTO `order` VALUES ('16', '1', '4598450230', '909.20');

4、实例对象
用户表和订单表分别对应两个实例对象,分别是:User.javaOrder.java,它们都在 com.yiibai.pojo 包中。
User.java代码内容如下:

package com.yiibai.pojo;

import java.util.List;

/** 
 * @describe: User
 * @author: Yiibai 
 * @version: V1.0
 * @copyright http://www.yiibai.com
 */  
public class User {
    
    
	private int id;
	private String username;
	private String mobile;
	
	public int getId() {
    
    
		return id;
	}
	public void setId(int id) {
    
    
		this.id = id;
	}
	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;
	}
	
}

Order.java代码内容如下:

package com.yiibai.pojo;

/**
 * @describe: User - 订单
 * @author: Yiibai
 * @version: V1.0
 * @copyright http://www.yiibai.com
 */
public class Order {
    
    
	private int orderId;
	private String orderNo;
	private float money;
	private int userId;
	private User user;
	
	
	public int getUserId() {
    
    
		return userId;
	}
	public void setUserId(int userId) {
    
    
		this.userId = userId;
	}
	public int getOrderId() {
    
    
		return orderId;
	}
	public void setOrderId(int orderId) {
    
    
		this.orderId = orderId;
	}
	public User getUser() {
    
    
		return user;
	}
	public void setUser(User user) {
    
    
		this.user = user;
	}
	public String getOrderNo() {
    
    
		return orderNo;
	}
	public void setOrderNo(String orderNo) {
    
    
		this.orderNo = orderNo;
	}
	public float getMoney() {
    
    
		return money;
	}
	public void setMoney(float money) {
    
    
		this.money = money;
	}

}

5、配置文件
配置springMVC:
web.xml:

<?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" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
	id="WebApp_ID" version="2.5">
	<display-name>MyBatis_Spring_MVC</display-name>
	<welcome-file-list>
		<welcome-file>index.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>forceEncoding</param-name>
			<param-value>true</param-value>
		</init-param>
	</filter>
	<filter-mapping>
		<filter-name>encodingFilter</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-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>
	<listener>
		<listener-class>
			org.springframework.web.context.ContextCleanupListener</listener-class>
	</listener>
	<servlet>
		<servlet-name>spring-mvc</servlet-name>
		<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
		<load-on-startup>1</load-on-startup>
	</servlet>
	<servlet-mapping>
		<servlet-name>spring-mvc</servlet-name>
		<url-pattern>/</url-pattern>
	</servlet-mapping>

</web-app>

spring-mvc-servlet.xml:

<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://www.springframework.org/schema/beans     
        http://www.springframework.org/schema/beans/spring-beans-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/mvc
        http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">
	<context:component-scan base-package="com.yiibai.controller" />
	
	<bean
		class="org.springframework.web.servlet.view.InternalResourceViewResolver">
		<property name="prefix">
			<value>/WEB-INF/pages/</value>
		</property>
		<property name="suffix">
			<value>.jsp</value>
		</property>
	</bean>

</beans>

这个实例中有三个重要的配置文件,它们分别是:applicationContext.xmlConfiguration.xml 以及 UserMaper.xml
applicationContext.xml 配置文件里最主要的配置:

<?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:aop="http://www.springframework.org/schema/aop"
	xmlns:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context"
	xmlns:p="http://www.springframework.org/schema/p"
	xsi:schemaLocation="  
            http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.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/jee http://www.springframework.org/schema/jee/spring-jee-3.0.xsd  
            http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd"
	default-autowire="byName" default-lazy-init="false">

	<!--本示例采用DBCP连接池,应预先把DBCP的jar包复制到工程的lib目录下。 -->
	<context:property-placeholder location="classpath:/config/database.properties" />

	<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
		destroy-method="close" p:driverClassName="com.mysql.jdbc.Driver"
		p:url="jdbc:mysql://127.0.0.1:3306/yiibai?characterEncoding=utf8"
		p:username="root" p:password="" p:maxActive="10" p:maxIdle="10">
	</bean>

	<bean id="transactionManager"
		class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
		<property name="dataSource" ref="dataSource" />
	</bean>

	<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
		<!--dataSource属性指定要用到的连接池-->
		<property name="dataSource" ref="dataSource" />
		<!--configLocation属性指定mybatis的核心配置文件-->
		<property name="configLocation" value="classpath:config/Configuration.xml" />
		<!-- 所有配置的mapper文件 -->
		<property name="mapperLocations" value="classpath*:com/yiibai/mapepr/*.xml" />
	</bean>

	<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
		<property name="basePackage" value="com.yiibai.maper" />
	</bean>
</beans> 

Configuration.xml:

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <typeAliases> 
        <typeAlias alias="User" type="com.yiibai.pojo.User"/>
        <typeAlias alias="Order" type="com.yiibai.pojo.Order"/>  
    </typeAliases> 
    <!-- 与spring 集成之后,这些可以完全删除,数据库连接的管理交给 spring 去管理 -->
    <!-- 
	<environments default="development">
		<environment id="development">
		<transactionManager type="JDBC"/>
			<dataSource type="POOLED">
			<property name="driver" value="com.mysql.jdbc.Driver"/>
			<property name="url" value="jdbc:mysql://127.0.0.1:3306/mybatis?characterEncoding=utf8" />
			<property name="username" value="root"/>
			<property name="password" value="password"/>
			</dataSource>
		</environment>
	</environments>
	-->
	
	<!-- 这里交给sqlSessionFactory 的 mapperLocations属性去得到所有配置信息 -->
	<!-- 
	<mappers>
	    <mapper resource="com/yihaomen/mapper/User.xml"/>
	</mappers>
	--> 
	
</configuration>

UserMaper.xml 用于定义查询和数据对象映射,其内容如下:

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" 
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.yiibai.maper.UserMaper">
	
		<!-- 为了返回list 类型而定义的returnMap -->
	<resultMap type="User" id="resultUser">
        <id column="id" property="id" />
        <result column="username" property="username" />
        <result column="mobile" property="mobile" />
    </resultMap>
    
	<!-- User 联合 Order 查询 方法的配置 (多对一的方式)  -->	
	<resultMap id="resultUserOrders" type="Order">
	    <id property="orderId" column="order_id" />
	    <result property="orderNo" column="order_no" />
	    <result property="money" column="money" />
	    <result property="userId" column="user_id" />
	    
	    <association property="user" javaType="User">
	        <id property="id" column="id" />
	        <result property="username" column="username" />
	        <result property="mobile" column="mobile" />	        
	    </association>	    
	</resultMap> 
	
	<select id="getUserOrders" parameterType="int" resultMap="resultUserOrders">
	   SELECT u.*,o.* FROM `user` u, `order` o 
	          WHERE u.id=o.user_id AND u.id=#{id}
	</select>
	
	<select id="getUserById" resultMap="resultUser" parameterType="int">
		SELECT *
		FROM user
		WHERE id=#{id}
	</select>    
</mapper>

6、测试执行,输出结果
UserController:

package com.yiibai.controller;

import java.util.List;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
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.yiibai.maper.UserMaper;
import com.yiibai.pojo.Order;

/** 
 * @describe: 读取一个用户下的所有订单
 * @author: Yiibai 
 * @version: V1.0
 * @copyright http://www.yiibai.com
 */ 

// http://localhost:8080/mybatis07-spring-mvc/user/orders
@Controller
@RequestMapping("/user")
public class UserController {
    
    
	@Autowired
	UserMaper userMaper;

	@RequestMapping("/orders")
	public ModelAndView listall(HttpServletRequest request,HttpServletResponse response){
    
    
		List<Order> orders=userMaper.getUserOrders(1); 
		System.out.println("orders");
		ModelAndView mav=new ModelAndView("user_orders");
		mav.addObject("orders",orders);
		return mav;
	}
}

接下来还需要创建一个 web 页面作为结果输出,在目录 WebRoot/WEB-INF/pages 下创建一个名为 user_orders.jsp 文件,其代码如下:

<%@ 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>用户订单列表</title>
	</head>
	<body>
		<c:forEach items="${orders}" var="order">  
        订单号:${order.orderNo },订单总额:${order.money }<br />
		</c:forEach>
	</body>
</html>

在浏览器中打开网址:http://localhost:8080/mybatis07-spring-mvc/user/orders
输出结果如下图所示:
在这里插入图片描述

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转载自blog.csdn.net/weixin_43278644/article/details/87855098
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