Mybatis使用

1. 第一个Mybatis程序  Mybatis-01

1.1 mybatis-config编写

<?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="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useUnicode=true&amp;characterEncoding=UTF-8"/>
                <property name="username" value="root"/>
                <property name="password" value="123456"/>
            </dataSource>
        </environment>
    </environments>
<mappers>
<mapper resource="com/zhx/mapper/UserMapper.xml"/>
</mappers>
</configuration>

 

1.2 工具类

package com.zhx.utils;

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 java.io.IOException;
import java.io.InputStream;

public class MybatisUtils {
    private static SqlSessionFactory sqlSessionFactory;
    static {
        try {
            String resource = "mybatis-config.xml";
            InputStream inputstream = Resources.getResourceAsStream(resource);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputstream);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static SqlSession getSqlSession(){
        return sqlSessionFactory.openSession();
    }
}

 

1.3 实体类 (对照数据库创建)

package com.zhx.pojo;

public class User {
    private int id;
    private String name;
    private String pwd;

    public User() {
    }

    public User(int id, String name, String pwd) {
        this.id = id;
        this.name = name;
        this.pwd = pwd;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPwd() {
        return pwd;
    }

    public void setPwd(String pwd) {
        this.pwd = pwd;
    }
}

 

1.4 mapper接口

package com.zhx.mapper;

import com.zhx.pojo.User;

import java.util.List;

public interface UserMapper {
    List<User> getUserList();
}

 

1.5 对应的 xml配置文件   (代替原生方式的实现类)

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.zhx.mapper.UserMapper"> <!--配置文件必须写全限定名 -->
   <select id="getUserList" resultType="com.zhx.pojo.User">
       select * from user
   </select>
</mapper>

 

1.6 测试

package com.zhx.mapper;

import com.zhx.pojo.User;
import com.zhx.utils.MybatisUtils;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;

import java.util.List;

public class UserMapperTest {
    @Test
    public void Test1(){
        SqlSession sqlSession = MybatisUtils.getSqlSession();

//        方式一
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        List<User> userList = mapper.getUserList();

//        方式二
        List<User> userList1 = sqlSession.selectList("com.zhx.mapper.UserMapper.getUserList");
        
        for (User user : userList1) {
            System.out.println(user);
        }
        sqlSession.close();
    }
}

 

 

2. Spring整合mybatis   Mybatis-02  通过mybatis-spring包来整合

2.1 实体类

package com.zhx.pojo;

public class User {
    private int id;
    private String name;
    private String pwd;

    public User() {
    }

    public User(int id, String name, String pwd) {
        this.id = id;
        this.name = name;
        this.pwd = pwd;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPwd() {
        return pwd;
    }

    public void setPwd(String pwd) {
        this.pwd = pwd;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", pwd='" + pwd + '\'' +
                '}';
    }
}

 

2.2 UserMapper

package com.zhx.mapper;

import com.zhx.pojo.User;

import java.util.List;

public interface UserMapper {
   public List<User> getUserList();
}

 

 

2.3  UserMapperImpl  和 UserMapperImpl_1

有继承 SqlSessionDaoSupport类的方法 和类 里面设置 SqlSessionTemplate属性两种方法

package com.zhx.mapper;

import com.zhx.pojo.User;
import org.mybatis.spring.SqlSessionTemplate;

import java.util.List;

public class UserMapperImpl implements UserMapper{
//    之前我们所有的操作都是用sqlSession来执行,现在都是用SqlSessionTemplate

    private SqlSessionTemplate sqlSessionTemplate;

    public void setSqlSessionTemplate(SqlSessionTemplate sqlSessionTemplate) {
        this.sqlSessionTemplate = sqlSessionTemplate;
    }

    @Override
    public List<User> getUserList() {
        UserMapper mapper = sqlSessionTemplate.getMapper(UserMapper.class);
        return mapper.getUserList();
    }
}

 

public class UserMapperImpl_1 extends SqlSessionDaoSupport implements UserMapper {

    @Override
    public List<User> getUserList() {
        SqlSession sqlSession = getSqlSession();
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        return mapper.getUserList();
    }
}

 

 

2.4 UserMapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.zhx.mapper.UserMapper">
    <select id="getUserList" resultType="com.zhx.pojo.User">
        select * from user
    </select>
</mapper>

2.5 mybatis-config.xml

<?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>
    <typeAliases>
        <package name="com.zhx.pojo"/>
    </typeAliases>

<!--    <mappers>-->
<!--        <mapper resource="com/zhx/mapper/UserMapper.xml"/>-->
<!--    </mappers>-->
</configuration>

 

2.4 spring-dao.xml

 

 

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

    <!--  定义一个使用DBCP实现的数据源 -->
    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useUnicode=true&amp;characterEncoding=UTF-8"/>
        <property name="username" value="root"/>
        <property name="password" value="123456"/>
    </bean>
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <property name="configLocation" value="classpath:mybatis-config.xml"/>
        <property name="mapperLocations" value="classpath:mapper/*"/>
    </bean>

    <bean id="sqlSessionTemplate" class="org.mybatis.spring.SqlSessionTemplate">
        <constructor-arg index="0" ref="sqlSessionFactory"/>
    </bean>

    <bean id="UserMapper" class="com.zhx.mapper.UserMapperImpl">
        <property name="sqlSessionTemplate" ref="sqlSessionTemplate"/>
    </bean>

    
<!--    因为UserMapperImpl_1继承了SqlSessionDaoSupport类,而SqlSessionDaoSupport类中有一个关于sqlSessionFactory的set方法
 所以这里直接注入sqlSessionFactory,SqlSessionDaoSupport类中又提供了getSqlSession方法-->
    <bean id="UserMapper2" class="com.zhx.mapper.UserMapperImpl_1">
        <property name="sqlSessionFactory" ref="sqlSessionFactory"/>
    </bean>
</beans>

 

3.  配置dao接口扫描包,动态的实现了dao接口可以注入到spring容器中。。不再需要实现类

注意:

<!--  配置Mapper接口扫描包,动态的实现了Mapper接口可以注入到Spring容器中! 配置
    此项后不再需要sqlSessionTemplate
 -->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
        <property name="basePackage" value="com.zhx.mapper"/>
    </bean>

 

 

 

 

 

 

posted @ 2021-10-06 16:57  木有呂朋友  阅读(36)  评论(0编辑  收藏  举报