mybatis configuration properties properties

MyBatis provides three ways to use properties:

1, property sub-elements.

2, properties file.

3, the program code is transmitted.

properties property-based system configured for some operating parameters on the XML file or general file properties, which can better facilitate the parameter modification.

File name is: mybatis_config.xml. Look at the properties and properties property use.

<?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>
        <property name="jdbc.driver" value="com.mysql.jdbc.Driver"></property>
        <property name="jdbc.url" value="jdbc:mysql://localhost:3306/MyBatisDemo2"></property>
        <property name="jdbc.username" value="root"/>
        <property name="jdbc.password" value="root"/>
    </properties>
    <!--别名-->
    <typeAliases>
        <typeAlias alias="role" type=""/>
    </typeAliases>
    <!--数据库环境-->
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="${jdbc.driver}"/>
                <property name="url" value="${jdbc.url}"/>
                <property name="username" value="${jdbc.username}"/>
                <property name="password" value="${jdbc.password}"/>
            </dataSource>
        </environment>
    </environments>
    <!--映射文件-->
    <mappers>
        <mapper resource=""/>
    </mappers>
</configuration>

<proerties> erupted element <property> definition, only defined once and can be referenced everywhere . But when too many attribute parameters, recommends the following: the Properties file way to solve.

properties File name: jdbc.properties

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/hr?serverTimezone=GMT
jdbc.username=root
jdbc.password=root

There are two ways to use external configuration

The first attribute url

 <!--注意顺序哦!-->
    <properties url="file:///e:/政通路/课堂笔记/S2/day01_mybatis_demo/src/main/resources/jdbcConfig.properties">
    </properties>

The second resource property (common)

<properties resource="jdbcConfig.properties"></properties>

Detailed configuration used:

<property name="driver" 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>