Maven MyBatis快速入门

1、在IDEA中创建Maven项目

Maven 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.xiaobai</groupId>
  <artifactId>MyBatis_Maven</artifactId>
  <version>1.0-SNAPSHOT</version>
  <packaging>war</packaging>

  <name>MyBatis_Maven Maven Webapp</name>
  <!-- FIXME change it to the project's website -->
  <url>http://www.example.com</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.7</maven.compiler.source>
    <maven.compiler.target>1.7</maven.compiler.target>
  </properties>

  <dependencies>
    <!--MyBatis -->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.4.6</version>
    </dependency>
    <!--MariaDB数据库驱动 -->
    <dependency>
      <groupId>org.mariadb.jdbc</groupId>
      <artifactId>mariadb-java-client</artifactId>
      <version>2.3.0</version>
    </dependency>
    <!-- JUnit单元测试工具 -->
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
    </dependency>
  </dependencies>

  <build>
    <finalName>MyBatis_Maven</finalName>
    <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
      <plugins>
        <plugin>
          <artifactId>maven-clean-plugin</artifactId>
          <version>3.0.0</version>
        </plugin>
        <!-- see http://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_war_packaging -->
        <plugin>
          <artifactId>maven-resources-plugin</artifactId>
          <version>3.0.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-compiler-plugin</artifactId>
          <version>3.7.0</version>
        </plugin>
        <plugin>
          <artifactId>maven-surefire-plugin</artifactId>
          <version>2.20.1</version>
        </plugin>
        <plugin>
          <artifactId>maven-war-plugin</artifactId>
          <version>3.2.0</version>
        </plugin>
        <plugin>
          <artifactId>maven-install-plugin</artifactId>
          <version>2.5.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-deploy-plugin</artifactId>
          <version>2.8.2</version>
        </plugin>
      </plugins>
    </pluginManagement>
  </build>
</project>

2、创建数据库

use test;
drop table if exists person;
create table person
(
	bId int primary key auto_increment,
	bName varchar(10) not null
)default charset = utf8;

3、添加MyBatis配置文件

mybatis-config.xml文件内容如下：

<?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>

    <!--定义可以复用的变量-->
    <properties resource="jdbc.properties"/>

    <!--给类设置别名，简化xml文件-->
    <!--<typeAliases>-->
        <!--<typeAlias alias="entity" type="com.xiaobai.entity.CustomerEntity"/>-->
        <!--<!–扫描该包下的所有类–>-->
        <!--<package name="com.xiaobai.entity"/>-->
    <!--</typeAliases>-->

    <!--类型转换器-->
    <!--<typeHandlers>-->
        <!--<typeHandler handler="com.xiaobai.dao.InvoiceDAO"/>-->
        <!--<package name="com.xiaobai.dao"/>-->
    <!--</typeHandlers>-->

    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"></transactionManager>
            <dataSource type="POOLED">
                <property name="driver" value="${driver}"/>
                <property name="url" value="${url}"/>
                <property name="username" value="${username}"/>
                <property name="password" value="${password}"/>
            </dataSource>
        </environment>
    </environments>

    <!--指定映射器-->
    <mappers>
        <mapper resource="Invoice.xml" />
　　　　 <mapper resource="PersonMapper.xml" />
    </mappers>

</configuration>

jdbc.properties 文件内容如下：

driver = org.mariadb.jdbc.Driver
url = jdbc:mariadb://localhost:3306/test
username = root
password = Qi1007..

解释

4、定义操作Person表的映射文件

在resources目录下创建sql映射文件，在目录中创建一个PersonMapper.xml文件，如下图所示：

PersonMapper.xml文件内容如下：

<?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.xiaobai.dao.PersonDAO">
    <select id="selectOne" resultType="com.xiaobai.entity.Person">
        select * from person where bId=#{bId}
    </select>
</mapper>

 解释：

5、编写数据访问层 

package com.xiaobai.mybatis.dao;

import com.xiaobai.mybatis.entiy.Person;

public interface PersonDAO{

　　　Person selectOne(int bId);

}

6、编写单元测试类检查代码

package com;

import com.xiaobai.dao.InvoiceDAO;
import com.xiaobai.dao.PersonDAO;
import com.xiaobai.entity.InvoiceEntity;
import com.xiaobai.entity.Person;
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.Reader;

public class App {
    public static void main(String[] args) throws IOException {
        Reader reader = Resources.getResourceAsReader("mybatis-config.xml");
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);

        SqlSession session = sqlSessionFactory.openSession();

        PersonDAO personDAO = session.getMapper(PersonDAO.class);
        System.out.println(personDAO.selectOne(1));
//        InvoiceDAO invoiceDAO = session.getMapper(InvoiceDAO.class);
//        System.out.println(invoiceDAO.selectAll(1));
//        InvoiceEntity invoiceEntity = session.selectOne("com.xiaobai.dao.InvoiceDAO.selectOne",1);
//        System.out.println(invoiceEntity);
    }
}

结果：