mybatis-day01-优快云博客

本文链接：https://blog.youkuaiyun.com/yangsong199056/article/details/139421783

mybatis的学习日志–day01

一、mybatis框架的初认识

官方的地址：

官方的介绍：

MyBatis 是一款优秀的持久层框架，它支持自定义 SQL、存储过程以及高级映射。MyBatis 免除了几乎所有的 JDBC 代码以及设置参数和获取结果集的工作。MyBatis 可以通过简单的 XML 或注解来配置和映射原始类型、接口和 Java POJO（Plain Old Java Objects，普通老式 Java 对象）为数据库中的记录。

二、简单的一个demo

首先需要mybatis的jar包，如下：

 <groupId>org.mybatis</groupId>
 <artifactId>mybatis</artifactId>
  <version>3.5.2</version>

需要mysql的jar包

<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.16</version>

整体的maven的pom文件配置如下：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.mybatis</groupId>
    <artifactId>mybatis-001</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>
    <dependencies>
        <dependency>
            <!-- Mybatisjar包 -->
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.2</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.10</version>
        </dependency>
<!-- mysql的数据库驱动      -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.16</version>
        </dependency>

    </dependencies>

</project>

数据库配置文件,jdbc.properties


driver=com.mysql.cj.jdbc.Driver
url=jdbc:mysql://localhost:3306/user?serverTimezone=UTC
username=root
password = XXXXX

mybatis的主配置文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "https://mybatis.org/dtd/mybatis-3-config.dtd">
 <configuration>
    <!--通过配置文件的方式，从外部文件中获取数据源相关信息-->
    <properties resource="jdbc.properties"></properties>
    <settings>
        <!--增加日志框架的集成-->
        <setting name="logImpl" value="LOG4J"/>
    </settings>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"></transactionManager>
            <dataSource type="POOLED">
                <!--配置数据源 -->
                <property name="driver" value="${driver}"/>
                <property name="url" value="${url}"/>
                <property name="username" value="${username}"/>
                <property name="password" value="${password}"/>
            </dataSource>
        </environment>
    </environments>
   <mappers>
       <!--使用xml文件配置的方式实现-->
       <mapper resource="mybatis-user.xml"></mapper>
       <!--开启mybatis的注解-->
     <!--  <package name="org.mybatis.dao"/> -->
   </mappers>
</configuration>

mybatis的mapper的配置文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "https://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="org.mybatis.userMapper">
    <select id="selectUser" resultType="org.mybatis.bean.User">
        select *  from user where id = #{id}
    </select>
</mapper>

实体bean类

package org.mybatis.bean;

import lombok.Data;

@Data
public class User {
    private  long id;
    private String name;
    private String email;
    private int age;
    private String sex;
    private String schoolName;

}

测试程序代码

package org.mybatis;

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 org.mybatis.bean.User;
import org.mybatis.dao.UserMapper;

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

public class Mybatis01 {
    public static void main(String[] args) {
            String resource = "mybatis-config.xml";
        try {
            //获取数据流
            InputStream resourceAsStream = Resources.getResourceAsStream(resource);
            SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(resourceAsStream);
            SqlSession sqlSession = sqlSessionFactory.openSession();
            //UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
            User user = (User)sqlSession.selectOne("org.mybatis.userMapper.selectUser", 1);
           //User user =  userMapper.selectUser(1);
            System.out.println(user.toString());

        } catch (IOException e) {
            throw new RuntimeException(e);
        }

    }
}

验证输出结果

D:\Java\jdk1.8.0_191\bin\java.exe "-javaagent:D:\Program Files\IntelliJ IDEA 2023.1.2\lib\idea_rt.jar=58823:D:\Program Files\IntelliJ IDEA 2023.1.2\bin" -Dfile.encoding=UTF-8 -classpath D:\Java\jdk1.8.0_191\jre\lib\charsets.jar;D:\Java\jdk1.8.0_191\jre\lib\deploy.jar;D:\Java\jdk1.8.0_191\jre\lib\ext\access-bridge-64.jar;D:\Java\jdk1.8.0_191\jre\lib\ext\cldrdata.jar;D:\Java\jdk1.8.0_191\jre\lib\ext\dnsns.jar;D:\Java\jdk1.8.0_191\jre\lib\ext\jaccess.jar;D:\Java\jdk1.8.0_191\jre\lib\ext\jfxrt.jar;D:\Java\jdk1.8.0_191\jre\lib\ext\localedata.jar;D:\Java\jdk1.8.0_191\jre\lib\ext\nashorn.jar;D:\Java\jdk1.8.0_191\jre\lib\ext\sunec.jar;D:\Java\jdk1.8.0_191\jre\lib\ext\sunjce_provider.jar;D:\Java\jdk1.8.0_191\jre\lib\ext\sunmscapi.jar;D:\Java\jdk1.8.0_191\jre\lib\ext\sunpkcs11.jar;D:\Java\jdk1.8.0_191\jre\lib\ext\zipfs.jar;D:\Java\jdk1.8.0_191\jre\lib\javaws.jar;D:\Java\jdk1.8.0_191\jre\lib\jce.jar;D:\Java\jdk1.8.0_191\jre\lib\jfr.jar;D:\Java\jdk1.8.0_191\jre\lib\jfxswt.jar;D:\Java\jdk1.8.0_191\jre\lib\jsse.jar;D:\Java\jdk1.8.0_191\jre\lib\management-agent.jar;D:\Java\jdk1.8.0_191\jre\lib\plugin.jar;D:\Java\jdk1.8.0_191\jre\lib\resources.jar;D:\Java\jdk1.8.0_191\jre\lib\rt.jar;D:\workspace\mybatisDay\mybatis-001\target\classes;D:\workspace\repositoryun3\org\mybatis\mybatis\3.5.2\mybatis-3.5.2.jar;D:\workspace\repositoryun3\org\projectlombok\lombok\1.18.10\lombok-1.18.10.jar;D:\workspace\repositoryun3\mysql\mysql-connector-java\8.0.16\mysql-connector-java-8.0.16.jar;D:\workspace\repositoryun3\com\google\protobuf\protobuf-java\3.6.1\protobuf-java-3.6.1.jar;D:\workspace\repositoryun3\log4j\log4j\1.2.17\log4j-1.2.17.jar org.mybatis.Mybatis01
0    [main] DEBUG org.apache.ibatis.logging.LogFactory  - Logging initialized using 'class org.apache.ibatis.logging.log4j.Log4jImpl' adapter.
4    [main] DEBUG org.apache.ibatis.logging.LogFactory  - Logging initialized using 'class org.apache.ibatis.logging.log4j.Log4jImpl' adapter.
75   [main] DEBUG org.apache.ibatis.datasource.pooled.PooledDataSource  - PooledDataSource forcefully closed/removed all connections.
75   [main] DEBUG org.apache.ibatis.datasource.pooled.PooledDataSource  - PooledDataSource forcefully closed/removed all connections.
75   [main] DEBUG org.apache.ibatis.datasource.pooled.PooledDataSource  - PooledDataSource forcefully closed/removed all connections.
76   [main] DEBUG org.apache.ibatis.datasource.pooled.PooledDataSource  - PooledDataSource forcefully closed/removed all connections.
327  [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction  - Opening JDBC Connection
2986 [main] DEBUG org.apache.ibatis.datasource.pooled.PooledDataSource  - Created connection 1045997582.
2987 [main] DEBUG org.apache.ibatis.transaction.jdbc.JdbcTransaction  - Setting autocommit to false on JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@3e58a80e]
3000 [main] DEBUG org.mybatis.userMapper.selectUser  - ==>  Preparing: select * from user where id = ? 
3094 [main] DEBUG org.mybatis.userMapper.selectUser  - ==> Parameters: 1(Integer)
3198 [main] DEBUG org.mybatis.userMapper.selectUser  - <==      Total: 1
User(id=1, name=易哥, email=yeecode@sample.com, age=18, sex=0, schoolName=Sunny School)