Mybatis配置

 Mybatis  pom.xml的配置

1.配置groupId

2.配置artifactId

3.配置版本

4.添加依赖

5.设置build (maven是通过pom.xml来执行任务的.其中的build标签描述了如何来编译打包项目,而具体的编译和打包工作是通过build中配置的plugin来完成的)

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.sy</groupId>
    <artifactId>0415_mybatis_day01</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <!--mybatis-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.4.6</version>
        </dependency>

        <!--log4j-->
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>

        <!--mysql-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.40</version>
        </dependency>

        <!--junit-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>



    </dependencies>


    <build>
        <!--强制找包的资源文件-->
        <resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.xml</include>
                </includes>
            </resource>
            <resource>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**/*.xml</include>
                    <include>**/*.properties</include>
                </includes>
            </resource>
        </resources>
    </build>


</project>

1.创建SqlSessionFactoryBuilder对像

2.创建SqlSessionFactory对像

3.获取session对象

 

package tools;

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 java.io.InputStream;

public class MybatisUtil {

    private static SqlSessionFactory factory;

    static {
        try{
            InputStream inputStream = Resources.getResourceAsStream("mybatis-config.xml");
            //2.创建SqlSessionFactoryBuilder对像
            SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
            //3.创建SqlSessionFactory对像
            factory = builder.build(inputStream);
            //释放builder
            builder = null;
        }catch (Exception e){
            e.printStackTrace();
        }
    }

    /**
     * 获取session对像
     * @return
     */
    public static SqlSession openSession(){
        return factory.openSession();
    }
}

 mybatis-config.xml配置

1.引入连接数据库properties文件

2.事务的配置，使用JDBC事务

3.连接信息

4.数据源：生成connection对象，把connection对象放在连接池中

5.引入mapper映射文件，读取映射规则

<?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">

<!--数据库的连接信息和事务等-->
<configuration>
    <!--引入外部的db.properties文件-->
    <properties resource="db.properties"></properties>
    <!--连接信息-->
    <environments default="development">
        <environment id="development">
            <!--事务:使用JDBC事务-->
            <transactionManager type="JDBC"></transactionManager>
            <!--数据源:生成connection对像,把connection对像放在连接池中-->
            <dataSource type="POOLED">
                <property name="driver" value="${db_driver}"></property>
                <property name="url" value="${db_url}"></property>
                <property name="username" value="${db_user}"></property>
                <property name="password" value="${db_password}"></property>
            </dataSource>
        </environment>
    </environments>

    <!--引入maaper映射文件:读取映射规则-->
    <mappers>
        <!--加载映射文件-->
        <!--<mapper resource="mapper/UserMapper.xml"></mapper>-->
        <!--加载接口-->
        <!-- <mapper class="mapper.UserMapper"></mapper>-->
        <!--加载接口所在的包-->
        <package name="mapper"></package>
    </mappers>
</configuration>