Mybatis-使用xml配置环境创建会话工厂建立连接

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本文介绍了一个基于MyBatis的简单应用实例，包括环境配置文件、映射文件、Mapper接口及实体类的设计，并展示了如何通过启动类进行数据查询。

xml环境配置文件：

mybatis-config.xml

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>

    <!--设置-->
    <settings>
        <!--启用驼峰命名规则-->
        <setting name="mapUnderscoreToCamelCase" value="true"/>
    </settings>

    <!--定义别名-->
    <typeAliases>
        <typeAlias alias="book" type="cn.rogueq.entity.Book"/>
    </typeAliases>


    <!--定义数据库信息，默认使用development数据库构建环境-->
    <environments default="development">
        <environment id="development">
            <!--采用jdbc事务管理-->
            <transactionManager type="JDBC"></transactionManager>
            <!--配置数据库链接信息-->
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                <property name="url"
                          value="jdbc:mysql://127.0.0.1:3306/rogueq?serverTimezone=UTC"/>
                <property name="username" value="root"/>
                <property name="password" value="root"/>
            </dataSource>
        </environment>
    </environments>

    <!--定义映射器-->
    <mappers>
        <mapper resource="cn/rogueq/mybatis/BookMapper.xml"/>
    </mappers>

</configuration>

映射文件：

BookMapper.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="cn.rogueq.mybatis.BookMapper">
    <select id="selectById" resultType="book">
        select * from book where id = #{id}
    </select>
</mapper>

Mapper接口：

package cn.rogueq.mybatis;

import cn.rogueq.entity.User;
import org.apache.ibatis.annotations.Param;

public interface UserMapper {

    User selectById(@Param("id") Long id);

}

实体类：

package cn.rogueq.entity;

import java.util.Date;

public class Book {
    private Long id;
    private String name;
    private String author;
    private Date insertTime;
    private Date updateTime;

    public Long getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

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

    public String getAuthor() {
        return author;
    }

    public void setAuthor(String author) {
        this.author = author;
    }

    public Date getInsertTime() {
        return insertTime;
    }

    public void setInsertTime(Date insertTime) {
        this.insertTime = insertTime;
    }

    public Date getUpdateTime() {
        return updateTime;
    }

    public void setUpdateTime(Date updateTime) {
        this.updateTime = updateTime;
    }

    @Override
    public String toString() {
        return "Book{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", author='" + author + '\'' +
                ", insertTime=" + insertTime +
                ", updateTime=" + updateTime +
                '}';
    }
}

启动类：

public class MyBatisDemo {
    public static void main(String[] args) {
        String resource = "mybatis-config.xml";
        try {
            InputStream inputStream = Resources.getResourceAsStream(resource);
            SqlSessionFactory sqlSessionFactory = null;
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
            SqlSession sqlSession = sqlSessionFactory.openSession();
            BookMapper mapper = sqlSession.getMapper(BookMapper.class);
            Book book = mapper.selectById(1L);
            System.out.println(book);
        } catch (IOException e) {
            e.printStackTrace();
        }

    }
}

执行结果：

Book{id=1, name='深入浅出Mybatis技术原理与实战', author='杨开振', insertTime=Tue Mar 26 06:43:47 CST 2019, updateTime=Tue Mar 26 06:43:47 CST 2019}