mybatis快速入门-spring-mybatis整合

Posted 2020-10-08

今天写写spring-mybatis整合吧，先写个原始dao类的整合，下一节在写个动态代理的整合，我就不写太详细了，因为前面的章节基本上都有了，我直接就一口气都写出来需要那些文件然后在直接贴代码，首先创建一个java项目,。

首先导入jar包，jar地址下载

目录结构

 

1.db.properties数据连接池

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/mybatis
jdbc.username=root
jdbc.password=root

2.applicationContext.xml，spring的xml映射文件

<?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:mvc="http://www.springframework.org/schema/mvc"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
        http://www.springframework.org/schema/beans/spring-beans-3.2.xsd 
        http://www.springframework.org/schema/mvc 
        http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd 
        http://www.springframework.org/schema/context 
        http://www.springframework.org/schema/context/spring-context-3.2.xsd 
        http://www.springframework.org/schema/aop 
        http://www.springframework.org/schema/aop/spring-aop-3.2.xsd 
        http://www.springframework.org/schema/tx 
        http://www.springframework.org/schema/tx/spring-tx-3.2.xsd ">
        
        <!-- 数据源配置 dbcp -->
        <context:property-placeholder location="classpath:db.properties"/>
       
        <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
            <property name="driverClassName" value="${jdbc.driver}"></property>
            <property name="url" value="${jdbc.url}"></property>
            <property name="username" value="${jdbc.username}"></property>
            <property name="password" value="${jdbc.password}"></property>
            <property name="maxActive" value="10"></property>
            <property name="maxIdle" value="5"></property>
        </bean>
        <!-- 创建sqlsessionfactory -->
        <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
            <property name="configLocation" value="mybatis/SqlMapConfig.xml"></property>
            <property name="dataSource" ref="dataSource"></property>
        </bean>
        <bean id="userDao" class="cn.my.sm.dao.UserDao" >
            <property name="sqlSessionFactory" ref="sqlSessionFactory"></property>
        </bean>
</beans>

3.SqlMapConfig.xml:mybatis的映射文件

<?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>
    <mappers>
        <mapper resource="sqlmap/User.xml"/>
    </mappers>
</configuration>

4.User.xml：实体类的映射文件,为了简便我就只写一个findById方法的映射了

<?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="cn.my.sm.mapper.UserDaoMapper">
    <select id="findById" parameterType="int" resultType="cn.my.sm.po.User">
        select * from user where id=#{id}
    </select>
</mapper>

 5.创建User.java实体类

package cn.my.sm.po;

import java.util.Date;

public class User {

    private int id;
    private String username;// 用户姓名
    private String sex;// 性别
    private Date birthday;// 生日
    private String address;// 地址
    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 getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
    public Date getBirthday() {
        return birthday;
    }
    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }
    @Override
    public String toString() {
        return "User [id=" + id + ", username=" + username + ", sex=" + sex + ", birthday=" + birthday + ", address="
                + address + "]";
    }
}

6.创建UserDao.java数据访问类

package cn.my.sm.dao;

import org.apache.ibatis.session.SqlSession;
import org.mybatis.spring.support.SqlSessionDaoSupport;

import cn.my.sm.po.User;
//原始dao层需要继承SqlSessionDaoSupport类,或者自己声明一个sqlsessionfactory对象，添加setget方法，然后自己根据sqlsessionfactory工厂获取sqlsession
public class UserDao extends SqlSessionDaoSupport {
    public User findById(int id){
        SqlSession session = this.getSqlSession();
        User user = session.selectOne("cn.my.sm.mapper.UserDaoMapper.findById", id);
        return user;
    }
}

7.创建测试类

package cn.my.sm.test;

import org.junit.Before;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import cn.my.sm.dao.UserDao;
import cn.my.sm.po.User;

@SuppressWarnings("resource")
public class TestUser {
    ApplicationContext context;
    @Before
    public void setUp(){
        context = new ClassPathXmlApplicationContext("classpath:spring/applicationContext.xml");
    }
    @Test
    public void testFindById(){
        UserDao userdao = (UserDao) context.getBean("userDao");
        User user = userdao.findById(1);
        System.out.println(user);
    }
}

允许结果：

User [id=1, username=王五, sex=2, birthday=null, address=null]

 这样就原始整合完了，今天写得比较草率，如果大家有疑问的可以加群号581591235或者留言。