mybatis源码分析二

时间：2024-10-11 19:03:08

这次分析mybatis的xml文件

1.

<?xml version="1.0" encoding="UTF-8" ?>

<configuration xmlns="http://mybatis.org/schema/mybatis-config"

               xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

               xsi:schemaLocation="http://mybatis.org/schema/mybatis-config http://mybatis.org/schema/mybatis-config.xsd">

xml编写...

</configuration>

　　2.资源配置

 <!--方法一： 从外部指定properties配置文件, 除了使用resource属性指定外，还可通过url属性指定url-->

    <!--方法二. 直接用name，value设置 -->

    <properties resource="org/apache/ibatis/builder/jdbc.properties">

        <property name="prop1" value="aaaa"/>

        <property name="jdbcTypeForNull" value="NULL" />

    </properties>

3.setting 标签

mybatis源码分析二

mybatis源码分析二

mybatis源码分析二

代码：

 <settings>

    <setting name="autoMappingBehavior" value="NONE"/>

    <setting name="autoMappingUnknownColumnBehavior" value="WARNING"/>

    <setting name="cacheEnabled" value="false"/>

    <setting name="proxyFactory" value="CGLIB"/>

    <setting name="lazyLoadingEnabled" value="true"/>

    <setting name="aggressiveLazyLoading" value="true"/>

    <setting name="multipleResultSetsEnabled" value="false"/>

    <setting name="useColumnLabel" value="false"/>

    <setting name="useGeneratedKeys" value="true"/>

    <setting name="defaultExecutorType" value="BATCH"/>

    <setting name="defaultStatementTimeout" value="10"/>

    <setting name="defaultFetchSize" value="100"/>

    <setting name="mapUnderscoreToCamelCase" value="true"/>

    <setting name="safeRowBoundsEnabled" value="true"/>

    <setting name="localCacheScope" value="STATEMENT"/>

    <setting name="jdbcTypeForNull" value="${jdbcTypeForNull}"/>

    <setting name="lazyLoadTriggerMethods" value="equals,clone,hashCode,toString,xxx"/>

    <setting name="safeResultHandlerEnabled" value="false"/>

    <setting name="defaultScriptingLanguage" value="org.apache.ibatis.scripting.defaults.RawLanguageDriver"/>

    <setting name="callSettersOnNulls" value="true"/>

    <setting name="logPrefix" value="mybatis_"/>

    <setting name="logImpl" value="SLF4J"/>

    <setting name="vfsImpl" value="org.apache.ibatis.io.JBoss6VFS"/>

    <setting name="configurationFactory" value="java.lang.String"/>

  </settings>

4. typeAliases是用来设置类路径别名的

    <typeAliases>

        <typeAlias alias="User" type="com.majing.learning.mybatis.entity.User"/>

    </typeAliases>

别名其他介绍：https://blog.****.net/luoposhushengyizhuce/article/details/80791797

5.mappers配置方式，一看就懂

<mappers>

    <mapper resource="org/apache/ibatis/builder/xsd/BlogMapper.xml"/>

    <mapper url="file:./src/test/java/org/apache/ibatis/builder/xsd/NestedBlogMapper.xml"/>

    <mapper class="org.apache.ibatis.builder.xsd.CachedAuthorMapper"/>

    <package name="org.apache.ibatis.builder.mapper"/>

  </mappers>

6.数据库标识：databaseIdProvider

️databaseIdProvider的type属性是必须的，不配置时会报错。上面这个属性值使用的是VendorDatabaseIdProvider类的别名。

️property子元素是配置一个数据库，其中的name属性是数据库名称，value是我们自定义的别名，通过别名我们可以在SQL语句中标识适用于哪种数据库运行。

  <databaseIdProvider type="DB_VENDOR">

    <property name="Apache Derby" value="derby"/>

  </databaseIdProvider>

或者多个：

<!--数据库厂商标示 -->

     <databaseIdProvider type="DB_VENDOR">

         <property name="Oracle" value="oracle"/>

         <property name="MySQL" value="mysql"/>

         <property name="DB2" value="d2"/>

    </databaseIdProvider>

7.environments 配置数据源：

  <environments default="development">

    <environment id="development">

      <transactionManager type="JDBC">

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

      </transactionManager>

      <dataSource type="UNPOOLED">

        <property name="driver" value="${driver}"/>

        <property name="url" value="${url}"/>

        <property name="username" value="${username}"/>

        <property name="password" value="${password}"/>

      </dataSource>

    </environment>

  </environments>

详细说明：https://blog.****.net/majinggogogo/article/details/71616712

8.typeHandlers type类型注册

<typeHandlers>

    <typeHandler javaType="String" handler="org.apache.ibatis.builder.CustomStringTypeHandler"/>

    <typeHandler javaType="String" jdbcType="VARCHAR" handler="org.apache.ibatis.builder.CustomStringTypeHandler"/>

    <typeHandler handler="org.apache.ibatis.builder.CustomLongTypeHandler"/>

    <package name="org.apache.ibatis.builder.typehandler"/>

  </typeHandlers>

...

  <objectFactory type="org.apache.ibatis.builder.ExampleObjectFactory">

    <property name="objectFactoryProperty" value="100"/>

  </objectFactory>

  <objectWrapperFactory type="org.apache.ibatis.builder.CustomObjectWrapperFactory" />

  <reflectorFactory type="org.apache.ibatis.builder.CustomReflectorFactory"/>

  <plugins>

    <plugin interceptor="org.apache.ibatis.builder.ExamplePlugin">

      <property name="pluginProperty" value="100"/>

    </plugin>

  </plugins>

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