MyBatis学习

MyBatis学习：

1、导包：

mysql驱动包：

mysql-connector-java-5.1.7-bin.jar

mybatis核心包：

mybatis-3.5.1.jar

mybatis依赖包：

ant-1.10.3.jar log4j-1.2.17.jar ant-launcher-1.10.3.jar commons-logging-1.2.jar slf4j-api-1.7.26.jar asm-7.0.jar log4j-api-2.11.2.jar log4j-core-2.11.2.jar javassist-3.24.1-GA.jar ognl-3.2.10.jar slf4j-log4j12-1.7.26.jar cglib-3.2.10.jar

2、添加日志配置文件（src下写配置文件：log4j.properties）

# Global logging configuration
log4j.rootLogger=DEBUG, stdout
# Console output...
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n

3、创建全局配置文件SqlMapConfig.xml（src下写SqlMapConfig.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>
    <!--加载配置文件-->
    <properties resource="dbconfig.properties"></properties>

    <environments default="development">
        <environment id="development">
            <!--配置JDBC事务控制，由mybatis进行管理-->
            <transactionManager type="JDBC"/>
            <!--配置数据源，采用dbcp连接池-->
            <dataSource type="POOLED">
                <property name="driver" value="${driver}"/>
                <property name="url" value="${url}"/>
                <property name="username" value="${username}"/>
                <property name="password" value="${password}"/>
            </dataSource>
        </environment>
    </environments>

</configuration>

4、添加数据库配置文件（src下写dbconfig.properties）

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/mybatis_study01?useUnicode=true&characterEncoding=utf8
username=root
password=root

5、Dao层搭建（在src下com.hwt包下创建mapper包（即dao），里面写接口既实现方法）

UserMapper：

package com.hwt.dao;

import com.hwt.model.User;
import com.hwt.vo.UserQueryVo;

import java.util.List;

public interface UserMapper {

    public User findUserById(int id);

    public int insertUser(User user);

}

创建imp包，里面写实现UserMapper.xml:

<?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.hwt.dao.UserMapper">
    <select id="findUserById" parameterType="int" resultType="user">
        select * from user where id=#{id};
    </select>

    <insert id="insertUser" parameterType="user">
        insert into user (username,birthday,sex,address) value(#{username},#{birthday},#{sex},#{address});
    </insert>
</mapper>

6、配置文件加载映射文件（src下总的sql配置文件sqlMapConfig.xml中配置）

<!--告诉mybatis加载映射文件-->
<mappers>
    <mapper resource="com/hwt/mapper/UserMapper.xml"></mapper>
</mappers>

7、测试

package com.hwt.test;

import com.hwt.model.User;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import java.io.IOException;
import java.io.InputStream;

public class Demo01 {
    SqlSession sqlSession = null;
    @Before
    public void before() throws IOException {
        //读取配置文件
        String resource = "SqlMapConfig.xml";
        InputStream is = Resources.getResourceAsStream(resource);
        //创建会话工厂
        SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(is);
        //打开会话
        sqlSession = sessionFactory.openSession();
    }
    @After
    public  void after(){
        //关闭会话
        sqlSession.commit();
    }
    @Test
    public void test01() throws IOException {
        //调用方法执行数据库操作
        User user = sqlSession.selectOne("findUserById", 10);
        System.out.println(user);
    }
}