MyBatis核心SqlSessionFactory的创造

MyBatis核心SqlSessionFactory的创建

SqlSessionFactory是每个MyBatis应用的核心

其实现方式有两种，使用配置文件或使用JAVA编码。

1.配置文件实现

<?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>
	<environments default="development">
		<environment id="development">
			<transactionManager type="JDBC" />
			<dataSource type="POOLED">
				<property name="driver" value="${driver}" />
				<property name="url" value="${url}" />
				<property name="username" value="${username}" />
				<property name="password" value="${password}" />
			</dataSource>
		</environment>
	</environments>
	
	<mappers>
		<mapper resource="org/mybatis/example/BlogMapper.xml" />
	</mappers>
	
</configuration>

使用时利用下面代码进行初始化

String resource = "org/mybatis/example/Configuration.xml"; 
Reader reader = Resources.getResourceAsReader(resource); 
SqlSessionFactory　sqlMapper = new SqlSessionFactoryBuilder().build(reader);

2.使用编码实现

DataSource dataSource = new PooledDataSource("com.mysql.jdbc.Driver",
                        "jdbc:mysql://localhost/mybatis?userUnicode=true&amp;characterEncoding=utf8", "admin", "123456");
        Environment environment = new Environment("test", new JdbcTransactionFactory(), dataSource);
        Configuration configuration = new Configuration(environment);
        configuration.addMapper(TestDao.class);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(configuration);

生命同期问题

SqlSessionFactoryBuilder　是用过即丢，其生命周期只存在于方法体内

SqlSessionFactory　单例，存在于整合应用运行时

MyBatis核心SqlSessionFactory的创造

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