mybatis 3 settings 예제

mybatis 3 settings

[MyBatis singleton class]

---

package meeton.web.util.mybatis;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

public class MyBatis {

    private static final MyBatis self = new MyBatis();

    public static MyBatis getInstance() {
        return self;
    }

    private SqlSessionFactory factory;

    private MyBatis() {
        reload();
    }

    public SqlSessionFactory getFactory() {
        return factory;
    }

    public void reload() {
        try {
            factory = new SqlSessionFactoryBuilder().build(Resources.getResourceAsReader("mybatis.xml"));
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }
}





[mybatis.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>

    <properties resource="config.properties"/>

    <environments default="default">
        <environment id="default">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="${jdbc.driverClassName}"/>
                <property name="url" value="${jdbc.url}"/>
                <property name="username" value="${jdbc.username}"/>
                <property name="password" value="${jdbc.password}"/>
                <property name="poolMaximumActiveConnections" value="20"/>
                <property name="poolMaximumIdleConnections" value="20"/>
                <property name="poolMaximumCheckoutTime" value="20000"/>
                <property name="poolPingEnabled" value="true"/>
                <property name="poolPingQuery" value="select 1"/>
                <property name="poolPingConnectionsNotUsedFor" value="43200"/>
                <property name="poolTimeToWait" value="30000"/>
                <property name="driver.encoding" value="UTF-8"/>
            </dataSource>
        </environment>
    </environments>

   <mappers>
        <mapper resource="root/sub1/sub2/sample.xml"/>
    </mappers>

</configuration>





[sample.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="test.mysql">

    <select id="selectAllUsers" resultType="Map">
        select * from user
    </select>

    <select id="selectUser" parameterType="String" resultType="Map">
        select * from user where user = #{user}
    </select>

</mapper>

출처 - http://yousik.blogspot.com/2012/04/mybatis-singleton-class-package-meeton.html

==================================================================================

여기서 눈여겨 볼 사항이 <property name="poolPingQuery" value="select 1"/> 이다.

기존에 validationQuery 대신 poolPingQuery로 사용 하고 있다.

다음은 각 pool 과 관련된 속성 값 설명이다.

<property name="poolMaximumActiveConnections" value="20"/>

 : 동시 활성화 할 커넥션 수

<property name="poolMaximumIdleConnections" value="20"/>

: 유휴상태의 커넥션 수

<property name="poolMaximumCheckoutTime" value="20000"/>

: 커넥션 요청 후 획득까지 기다리는 시간

<property name="poolPingEnabled" value="true"/>

: 커넥션 ping 테스트

<property name="poolPingQuery" value="select 1"/>

: 커넥션이 살아 있는지 확인할 쿼리

<property name="poolPingConnectionsNotUsedFor" value="43200"/>
: 커넥션이 얼마 동안 유휴상태면 닫히는지 판단하는 시간

<property name="poolTimeToWait" value="30000"/>

: 사용 불가능한 커넥션 기다리는 시간

<property name="poolPingConnectionsOlderThan" value="43200"/>

: 어떤 커넥션이 닫힐 상태인지 판단하는 기준시간