MyBatis SqlSessionFactory的幾種常見創建方式

原文鏈接：https://blog.csdn.net/jimolangge123/article/details/49228255

MyBatis框架主要是圍繞着SqlSessionFactory這個類進行的，這個的創建過程如下：

1. 定義一個Configuration對象，其中包含數據源、事務、mapper文件資源以及影響數據庫行為屬性設置settings
2. 通過配置對象，則可以創建一個SqlSessionFactoryBuilder對象
3. 通過 SqlSessionFactoryBuilder 獲得SqlSessionFactory 的實例。
4. SqlSessionFactory 的實例可以獲得操作數據的SqlSession實例，通過這個實例對數據庫進行操作

具體看看SqlSessionFactory的創建

一、通過Configuration.xml配置文件進行創建

  1.配置文件：

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<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd" > <configuration>      <properties resource= "ssm/jdbc.properties" ></properties>      <environments default = "development" >          <environment id= "development" >              <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}" />              </dataSource>          </environment>      </environments>              <mappers>          <mapper resource= "ssm/BlogMapper.xml" />      </mappers> </configuration>

2.讀取配置文件：

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package ssm;   import java.io.IOException; import java.io.Reader;   import org.apache.ibatis.io.Resources; import org.apache.ibatis.session.SqlSession; import org.apache.ibatis.session.SqlSessionFactory; import org.apache.ibatis.session.SqlSessionFactoryBuilder;   import com.sm.model.User;   public class GetSqlSessionFactoryFromXML {        public static void main(String[] args) throws IOException {          //配置文件的名稱          String resource = "ssm/configuration.xml" ;          //通過Mybatis包中的Resources對象很輕松的獲取到配置文件          Reader reader = Resources.getResourceAsReader(resource);          //通過SqlSessionFactoryBuilder創建          SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);          //獲得session實例          SqlSession session =sqlSessionFactory.openSession();          User user = new User();          user.setId( 8 );          //完成數據庫的插入          session.insert( "add" , user);          session.commit();          session.close();          System.out.println(sqlSessionFactory);      } }

二、在程序中構建這些對象來創建

 

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package ssm;   import java.sql.SQLException; import javax.sql.DataSource; import org.apache.ibatis.datasource.pooled.PooledDataSource; import org.apache.ibatis.mapping.Environment; import org.apache.ibatis.session.Configuration; import org.apache.ibatis.session.SqlSession; import org.apache.ibatis.session.SqlSessionFactory; import org.apache.ibatis.session.SqlSessionFactoryBuilder; import org.apache.ibatis.transaction.TransactionFactory; import org.apache.ibatis.transaction.jdbc.JdbcTransactionFactory; import com.sm.model.User;   public class GetSqlSessionFactoryFromProgram {        public static void main(String[] args) throws SQLException {          String driver = "oracle.jdbc.OracleDriver" ;          String url = "jdbc:oracle:thin:@localhost:1521:orcl" ;          String username= "scott" ;          String password= "tiger" ;          //創建使用緩存池的數據源          /*           * <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}"/>              </dataSource>           */          DataSource dataSource = new PooledDataSource(driver,url,username,password);                    //創建事務          /*           * <transactionManager type="JDBC" />           */          TransactionFactory transactionFactory =  new JdbcTransactionFactory();                    Environment environment = new Environment( "development" , transactionFactory, dataSource);                    Configuration configuration = new Configuration(environment);          //加入資源          /*           * <mapper resource="ssm/BlogMapper.xml"/>           */          configuration.addMapper(UserMapper. class );          SqlSessionFactory sqlSessionFactory = new  SqlSessionFactoryBuilder().build(configuration);          System.out.println(sqlSessionFactory);                    SqlSession session =  sqlSessionFactory.openSession();          User user = new User();          user.setId( 6 );          session.insert( "add" , user);          session.commit();          session.close();      } }

 

三、通過與Spring集成，由Spring容器管理創建

 

 1. 在spring的配置文件applicationContext.xml中配置

 

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<bean id= "sessionFactory" class = "org.mybatis.spring.SqlSessionFactoryBean" >         <property name= "dataSource" ref= "dataSource" />         <property name= "configLocation" value= "classpath*:conf/configuration.xml" />       </bean>

 

如果使用則直接注入，獲取SqlSessionFactory實例即可。