第一步:导包
由于包过多,这里就不一一介绍
注意:这里不能少mybatis-spring.jar这个包,这个包是用来联系Spring和Mybatis的
整个工程目录如下:
第二步:创建两张表(本人两张表分别为user和order),如下图所示:
user表:
order表:
第三步:编写相对应的实体类:
建议实体类名与表名同名(首字母大写)
User类:
package com.zhiyuan.Bean;
public class User {
private int id;
private String username;
private int 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 int getMobile() {
return mobile;
}
public void setMobile(int mobile) {
this.mobile = mobile;
}
}
Order类:
package com.zhiyuan.Bean;
public class Order {
private int oId;
private int uId;
private String orderNo;
private double money;
private User user;
public int getoId() {
return oId;
}
public void setoId(int oId) {
this.oId = oId;
}
public int getuId() {
return uId;
}
public void setuId(int uId) {
this.uId = uId;
}
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;
}
public User getUser() {
return user;
}
public void setUser(User user) {
this.user = user;
}
}
第四步:编写接口与mapper.xml文件
IUser接口:
package com.zhiyuan.Dao;
import java.util.List;
import com.zhiyuan.Bean.Order;
public interface IUser {
public List<Order> GetOrderID(int id);
//List<Order>:用来接收order表中的多条数据
}
order.xml文件:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "mybatis-3-mapper" "mybatis-3-mapper.dtd" >
<mapper namespace="com.zhiyuan.Dao.IUser">
<!-- namespace:命名空间,com.zhiyuan.Dao.IUser:接口路径 -->
<resultMap type="order" id="myMap">
<!-- type:如果在主配置文件中配置了别名,这里可以写别名,如没有配置这里写Order类全路径 -->
<result property="oId" column="order_id"/>
<!-- property:与实体类中的属性名保持一致,column与数据库里面的字段名保持一致 -->
<result property="uId" column="user_id"/>
<result property="orderNo" column="order_no"/>
<result property="money" column="money"/>
<association property="user" javaType="user" column="user_id">
<!-- 一对多用collection,多对一用association -->
<!-- ofType:和上面的type一样,column:user表中与order表有关系的字段 -->
<result property="id" column="u_id"/>
<result property="username" column="username"/>
<result property="mobile" column="mobile"/>
</association>
</resultMap>
<select id="GetOrderID" parameterType="int" resultMap="myMap">
<!-- id:唯一标识符,parameterType:传入参数类型,resultMap:本人理解为自定义返回参数类型,详细可以参考:http://www.cnblogs.com/fsjohnhuang/p/4076592.html,resultMap中aa与resultMap泛型id值保持一致 -->
select * from user,`order` where user.u_id=`order`.user_id and `user`.u_id=#{id}
<!-- 查询语句,#{id}:表示占位符 -->
</select>
</mapper>
第五步:编写config主配置文件
之前我们这里配置了三大块,分别是:别名,基础环境配置,映射文件,现在我们将我们的基础环境配置交给我们的spring容器来进行管理,所以我们这里的config主配置文件会有所不一样,代码如下:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration PUBLIC "mybatis-3-config" "mybatis-3-config.dtd" >
<configuration>
<!-- 设置别名 -->
<typeAliases>
<package name="com.zhiyuan.Bean"/>
<!-- 批量定义别名:
name:指定包名,mybatis自动扫描包中的类,自动定义别名,别名就是类名(首字母大小写都可以)
-->
</typeAliases>
<!-- 映射文件配置 -->
<mappers>
<mapper resource="com/zhiyuan/Dao/order.xml"/>
</mappers>
</configuration>
第六步:编写spring配置文件
springDefinition.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:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:jdbc="http://www.springframework.org/schema/jdbc"
xmlns:lang="http://www.springframework.org/schema/lang"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:task="http://www.springframework.org/schema/task"
xmlns:tx="http://www.springframework.org/schema/tx"
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/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/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"
default-autowire="byName">
<!-- default-autowire="byName":自动装配 -->
<!-- 数据源 -->
<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/springmybaitszhenghe"></property>
<property name="username" value="root"></property>
<property name="password" value="1234"></property>
</bean>
<!-- 回话工厂 -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource"></property>
<!-- 数据源 -->
<property name="configLocation" value="config.xml"></property>
<!-- 加载mybatis的配置文件 -->
</bean>
<!-- mapper配置
MapperFactoryBean:根据mapper接口生成代理对象
使用此方法的问题就是需要对每一个mapper进行配置,麻烦,如果有多个mapper就可以使用下面的mapper批量扫描
-->
<bean id="iuser" class="org.mybatis.spring.mapper.MapperFactoryBean">
<property name="sqlSessionFactory" ref="sqlSessionFactory"></property>
<property name="mapperInterface" value="com.zhiyuan.Dao.IUser"></property>
<!-- mapperInterface指定mapper接口 -->
</bean>
<!--
mapper批量扫描,从mapper包中扫描出mapper接口,自动创建代理对象并且在spring容器中注册
遵循规范:将mapper.java和mapper.xml映射文件名称保持一致,且在同一目录中
自动扫描出来的mapper的bean的id为mapper类名(首字母小写)
使用此方法可以不用在config.xml配置文件中扫描映射文件
-->
<!-- <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="包名"></property>
指定扫描的包名
如果扫描多个包,每个包中间使用半角逗号隔开
<property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"></property>
</bean> -->
</beans>
第七步:编写测试类
Text类:
package com.zhiyuan.Text;
import java.util.List;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.zhiyuan.Bean.Order;
import com.zhiyuan.Bean.User;
import com.zhiyuan.Dao.IUser;
public class Text {
public static void main(String[] args) {
ApplicationContext ac = new ClassPathXmlApplicationContext("springDefinition.xml");
//创建一个容器对象
IUser iuser = (IUser) ac.getBean("iuser");
//iuser是springDefinition.xml里面的id名
//从容器对象中拿到Bean类的对象,并用接口对象接收
List<Order> list = iuser.GetOrderID(1);
//使用接口对象调用接口中的方法并传入参数,再用接口的返回参数类型来进行接收
User user = null;
//引用User类,作用:获取下面order.getUser()方法
for (Order order : list) {
//使用for循环将list集合中的值一一打印出来
System.out.println("订单号:"+order.getOrderNo()+" 价格:"+order.getMoney());
user = order.getUser();
//用Order类的对象名调用Order类中的User,再将获取到的方法交给上面的User类
}
System.out.println("用户名"+user.getUsername());
//再用user属性名获取User类里面的值
}
}
log4j.properties文件
该文件里面的内容无需理解
log4j.rootLogger=WARN, stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d %p [%c] - %m%n
运行结果