mybatis原理_mybatis和ibatis区别_mybatis基本工作原理(5)

这种方式实现了MyBatis可以连接多数据源

*/

privatevoidenvironmentsElement(XNodecontext)throwsException

{

if(context!=null)

{

if(environment==null)

{

environment=context.getStringAttribute("default");

}

for(XNodechild:context.getChildren())

{

Stringid=child.getStringAttribute("id");

if(isSpecifiedEnvironment(id))

{

//1.创建事务工厂TransactionFactory

TransactionFactorytxFactory=transactionManagerElement(child.evalNode("transactionManager"));

DataSourceFactorydsFactory=dataSourceElement(child.evalNode("dataSource"));

//2.创建数据源DataSource

DataSourcedataSource=dsFactory.getDataSource();

//3.构造Environment对象

Environment.BuilderenvironmentBuilder=newEnvironment.Builder(id)

.transactionFactory(txFactory)

.dataSource(dataSource);

//4.将创建的Envronment对象设置到configuration对象中

configuration.setEnvironment(environmentBuilder.build());

}

}

}

}

privatebooleanisSpecifiedEnvironment(Stringid)

{

if(environment==null)

{

thrownewBuilderException("Noenvironmentspecified.");

}

elseif(id==null)

{

thrownewBuilderException("Environmentrequiresanidattribute.");

}

elseif(environment.equals(id))

{

returntrue;

}

returnfalse;

}

4. 返回Configuration对象

我们将上述的MyBatis初始化基本过程的序列图细化，

三、手动加载XML配置文件创建Configuration对象完成初始化，创建并使用SqlSessionFactory对象

我们可以使用XMLConfigBuilder手动解析XML配置文件来创建Configuration对象，代码如下：

Stringresource="mybatis-config.xml";

InputStreaminputStream=Resources.getResourceAsStream(resource);

//手动创建XMLConfigBuilder，并解析创建Configuration对象

XMLConfigBuilderparser=newXMLConfigBuilder(inputStream,null,null);

本文来自电脑杂谈，转载请注明本文网址：
http://www.pc-fly.com/a/tongxinshuyu/article-40254-5.html