两种方式（xml+代码）构建SqlSessionFactory+完整实现

首先创建类、接口、数据库：

entity包下Admin类：

package com.wbg.springJavaConfig.entity;

public class Admin {
    private int aId;
    private String aAccount;
    private String aPassword;
    private String aRank;

    public Admin(int aId, String aAccount, String aPassword, String aRank) {
        this.aId = aId;
        this.aAccount = aAccount;
        this.aPassword = aPassword;
        this.aRank = aRank;
    }

    public int getaId() {
        return aId;
    }

    public void setaId(int aId) {
        this.aId = aId;
    }

    public String getaAccount() {
        return aAccount;
    }

    public void setaAccount(String aAccount) {
        this.aAccount = aAccount;
    }

    public String getaPassword() {
        return aPassword;
    }

    public void setaPassword(String aPassword) {
        this.aPassword = aPassword;
    }

    public String getaRank() {
        return aRank;
    }

    public void setaRank(String aRank) {
        this.aRank = aRank;
    }

    @Override
    public String toString() {
        return "Admin{" +
                "aId=" + aId +
                ", aAccount='" + aAccount + '\'' +
                ", aPassword='" + aPassword + '\'' +
                ", aRank='" + aRank + '\'' +
                '}';
    }
}

　dao包下的AdminDao接口

public interface AdminDao {

    List<Admin> listAll();
    Admin getById(int aId);
}

service包下AdminService

public interface AdminService {
    List<Admin> listAll();

    Admin getById(int aId);
}

impl包下AdminServiceImpl

public class AdminServiceImpl implements AdminService {

    @Override
    public List<Admin> listAll() {
        return null;
    }

    @Override
    public Admin getById(int aId) {
        return null;
    }
}

一、使用xml构建SqlSessionFactory

 <!-- 数据库连接池 -->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="org.mariadb.jdbc.Driver" />
        <property name="jdbcUrl" value="jdbc:mariadb://localhost:3306/wbg_logistics" />
        <property name="user" value="root" />
        <property name="password" value="123456" />

        <!-- c3p0连接池的私有属性 -->
        <property name="maxPoolSize" value="30" />
        <property name="minPoolSize" value="10" />
        <!-- 关闭连接后不自动commit -->
        <property name="autoCommitOnClose" value="false" />
        <!-- 获取连接超时时间 -->
        <property name="checkoutTimeout" value="10000" />
        <!-- 当获取连接失败重试次数 -->
        <property name="acquireRetryAttempts" value="2" />
    </bean>

    <!-- 配置SqlSessionFactory对象 -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!-- 注入数据库连接池 -->
        <property name="dataSource" ref="dataSource" />
        <!-- 配置MyBaties全局配置文件:mybatis-config.xml -->
        <property name="configLocation" value="classpath:mybatis-config.xml" />
        <!-- 扫描entity包 使用别名 -->
        <property name="typeAliasesPackage" value="com.wbg.springJavaConfig.dao" />
        <!-- 扫描sql配置文件:mapper需要的xml文件 -->
        <property name="mapperLocations" value="classpath:mapper/*.xml" />
    </bean>

二、使用代码构建SqlSessionFactory

第一步：配置DataSource

有三种方式，推荐使用C3p0

 /**
     * C3p0的连接池
     * @return
     * @throws PropertyVetoException
     */
   @Bean
    public DataSource getC3p0DataSource() throws PropertyVetoException {
        ComboPooledDataSource dataSource=new ComboPooledDataSource();
        dataSource.setDriverClass("org.mariadb.jdbc.Driver");
        dataSource.setJdbcUrl("jdbc:mariadb://localhost:3306/wbg_logistics");
        dataSource.setUser("root");
        dataSource.setPassword("123456");
        dataSource.setMaxPoolSize(30);
        return dataSource;
    }
    /**
     * MyBatis的连接池
     * @return
     */
    //@Bean
    public DataSource getMyBatisDataSource(){
        //数据库连接池
        PooledDataSource dataSource = new PooledDataSource();
        //设驱动
        dataSource.setDriver("org.mariadb.jdbc.Driver");
        //用户名
        dataSource.setUsername("root");
        //密码
        dataSource.setPassword("123456");
        //数据库连接
        dataSource.setUrl("jdbc:mariadb://localhost:3306/wbg_logistics");
        dataSource.setDefaultAutoCommit(false);
        return dataSource;
    }
    /**
     * Spring自带的SimpleDriverDataSource
     * @return
     */
    //@Bean
    public DataSource getSimpleDriverDataSource(){
        SimpleDriverDataSource dataSource=new SimpleDriverDataSource();
       return dataSource;
    }

第二步：配置SqlSessionFactoryBean

需要xml配置的代码：

 /**
     * 获取SqlSessionFactoryBean
     *
     * @return
     */
    @Bean
    public SqlSessionFactoryBean getSqlSessionFactory(DataSource dataSource){
        SqlSessionFactoryBean sqlSessionFactoryBean=new SqlSessionFactoryBean();
        //注入数据库连接池
        sqlSessionFactoryBean.setDataSource(dataSource);
        //配置MyBaties全局配置文件:mybatis-config.xml
        sqlSessionFactoryBean.setConfigLocation(new ClassPathResource("mybatis-config.xml"));
        //扫描entity包 使用别名
        sqlSessionFactoryBean.setTypeAliasesPackage("com.wbg.springJavaConfig.dao");
        //扫描sql配置文件:mapper需要的xml文件
        sqlSessionFactoryBean.setMapperLocations(new Resource[]{new ClassPathResource("classpath:mapper/*.xml")});
        return sqlSessionFactoryBean;
    }

不需要xml的方式：

MySqlSessionFactory 类

package com.wbg.springJavaConfig.Mybatis;

import com.mchange.v2.c3p0.ComboPooledDataSource;
import com.wbg.springJavaConfig.dao.AdminDao;
import com.wbg.springJavaConfig.entity.Admin;
import org.apache.ibatis.datasource.pooled.PooledDataSource;
import org.apache.ibatis.mapping.Environment;
import org.apache.ibatis.session.*;
import org.apache.ibatis.transaction.TransactionFactory;
import org.apache.ibatis.transaction.jdbc.JdbcTransactionFactory;

import javax.sql.DataSource;
import java.beans.PropertyVetoException;

public class MySqlSessionFactory  {

    public static SqlSession getopenSession() throws PropertyVetoException {
        SqlSessionFactory sqlSessionFactory=getSqlSessionFactory(getC3p0DataSource());
        sqlSessionFactory.openSession();
        SqlSession sqlSession=null;
        try {
            //打开SqlSession会话
            sqlSession = sqlSessionFactory.openSession();
            sqlSession.commit();//提交事务
        }catch (Exception ex){
            sqlSession.rollback();//回滚
        }
        return sqlSession;
    }

    public static DataSource getC3p0DataSource() throws PropertyVetoException {
        ComboPooledDataSource dataSource=new ComboPooledDataSource();
        dataSource.setDriverClass("org.mariadb.jdbc.Driver");
        dataSource.setJdbcUrl("jdbc:mariadb://localhost:3306/wbg_logistics");
        dataSource.setUser("root");
        dataSource.setPassword("123456");
        dataSource.setMaxPoolSize(30);
        return dataSource;
    }

    public static SqlSessionFactory getSqlSessionFactory(DataSource dataSource){

        TransactionFactory transactionFactory = new JdbcTransactionFactory();
        Environment environment = new Environment("development", transactionFactory, dataSource);
        //创建Configuration对象
        org.apache.ibatis.session.Configuration configuration = new org.apache.ibatis.session.Configuration(environment);
        //注册一个MyBatis上下文别名
        configuration.getTypeAliasRegistry().registerAlias("admin", Admin.class);
        //加入一个映射器
        configuration.addMapper(AdminDao.class);
        //使用SqlSessionFactoryBuilder构建SqlSessionFactory
        //构建SqlSessionFactory
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(configuration);

        return sqlSessionFactory;
    }

}

进行使用：

1、修改AdminDao首先使用@Select注解

  @Select("select * from Admin")
    List<Admin> listAll();

2、加入配置

 SqlSession sqlSession = new MySqlSessionFactory().getopenSession();

    public AdminServiceImpl() throws PropertyVetoException {
    }
    public List<Admin> listAll() {
     AdminDao adminDao = sqlSession.getMapper(AdminDao.class);
        return adminDao.listAll();
    }

调用：

 AdminServiceImpl adminService = new AdminServiceImpl();

        List<Admin> list=adminService.listAll();
        for (Admin admin : list) {
            System.out.println(admin);
        }

运行：