Mybatis入门配置

目录结构

package com.banyuan.pangu.dao;

import com.banyuan.pangu.domain.User;
import org.apache.ibatis.annotations.Select;

import java.util.List;

/**
 * @author: ZCJ
 * @Date: 2019-11-04 15:42
 * @Description:用户的持久层接口
 */
public interface IUserDao {
    /**
     * 查询所有操作
     */
@Select("select * from user")
    List<User> findAll();
}

实体类

package com.banyuan.pangu.domain;

import java.io.Serializable;
import java.util.Date;

/**
 * @author: ZCJ
 * @Date: 2019-11-04 15:38
 * @Description:
 */
public class User implements Serializable {
    private Integer id;
    private String username;
    private Date birthday;
    private String sex;
    private String address;


    public Integer getId() {
        return id;
    }

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

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public Date getBirthday() {
        return birthday;
    }

    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", birthday=" + birthday +
                ", sex='" + sex + '\'' +
                ", address='" + address + '\'' +
                '}';
    }
}

配置文件

<?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">
<!--主配置文件-->
<configuration>
    <!-- 指定 MyBatis 数据库配置文件 -->
    <properties resource="db.properties"/>

    <!--    配置环境-->
    <environments default="mysql">
        <!--    配置 mysql环境-->
        <environment id="mysql">
            <!--        配置事务类型-->
            <transactionManager type="JDBC"></transactionManager>
            <!--        配置数据源（连接池）-->
            <dataSource type="POOLED">

                <!--        配置连接数据库的基本信息-->
                <property name="driver" value="${driver}"/>
                <property name="url" value="${url}"/>
                <property name="username" value="${username}"/>
                <property name="password" value="${password}"/>

            </dataSource>
        </environment>
    </environments>
    <!--    映射配置文件  指定的是每个dao独立的配置文件-->
    <mappers>
        <!--        <mapper resource="com/banyuan/pangu/dao/IUserDao.xml"></mapper>-->
        <!--    下面的是注解，不用配映射文件-->
        <mapper class="com.banyuan.pangu.dao.IUserDao"></mapper>
    </mappers>
</configuration>

映射文件

<?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="com.banyuan.pangu.dao.IUserDao">
    <!--    配置查询所有-->
    <select id="findAll" resultType="com.banyuan.pangu.domain.User">
</select>

</mapper>

properties

driver=com.mysql.cj.jdbc.Driver
url=jdbc:mysql://localhost:3306/数据库
username=账号
password=密码

测试类

package com.banyuan.pangu.mybatis.test;

import com.banyuan.pangu.dao.IUserDao;
import com.banyuan.pangu.domain.User;
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;
import java.util.List;

/**
 * @author: ZCJ
 * @Date: 2019-11-04 16:28
 * @Description:
 */
public class MybatisTest {

    public static void main(String[] args) throws IOException {
        //1.读取配置文件
        InputStream in= Resources.getResourceAsStream("SqlMapConfig.xml");
        //2.创建SqlSessionFactory工厂
        SqlSessionFactoryBuilder builder=new SqlSessionFactoryBuilder();
        SqlSessionFactory factory=builder.build(in);
        //3.使用工厂生产SqlSession对象
        SqlSession session=factory.openSession();
        //4.使用SqlSession创建Dao接口的代理对象
        IUserDao userDao=session.getMapper(IUserDao.class);
        //5.使用代理对象执行方法
        List<User> users=userDao.findAll();
        for(User user:users){
            System.out.println(user);
        }
        //6.释放资源
        session.close();
        in.close();
    }
}

pom.xml

<?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>com.zcj</groupId>
    <artifactId>day01_mybatis</artifactId>
    <version>1.0-SNAPSHOT</version>
<packaging>jar</packaging>
    <dependencies>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.2</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.17</version>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.12</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

</project>

log4j

# Global logging configuration
log4j.rootLogger=ERROR, stdout

# MyBatis logging configuration...
log4j.logger.cn.mybatis.mydemo.mapper.PersonMapper=DEBUG
log4j.logger.cn.mybatis.mydemo.mapper.CardMapper=DEBUG

# Console output...
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n