MyBatis整合与逆向工程

MyBatis基本的使用方法

1.新建Maven工程

2.导入MyBatis依赖

  <dependencies>
    <!-- Junit测试框架，用作方法测试 -->
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>
    
    <!-- MyBatis核心依赖，就这一个 -->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.5.9</version>
    </dependency>
    <!-- MySQL数据库驱动 -->
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.47</version>
    </dependency>
  </dependencies>

3.MyBatis全局配置文件

<?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">
<configuration>

  <!-- 引入外部配置文件之后，就可以通过${}引入属性了 -->
  <properties resource="jdbc.properties"/>
  <!-- 配置环境为开发环境，当然还包括测试，生产 -->
  <environments default="development">
    <environment id="development">
      <!-- 事务管理器，使用了 JDBC 的提交和回滚设置，依赖于从数据源得到的连接来管理事务范围 -->
      <transactionManager type="JDBC"/>
      <!-- 数据源，POOLED标识带数据源的，会使用MyBatis默认的数据连接池，UNPOOLED就是不带的，尽量带数据源，因为JDBC事务提交依赖连接保证事务的原子性 -->
      <dataSource type="POOLED">
        <property name="driver" value="${driver}"/>
        <property name="url" value="${url}"/>
        <property name="username" value="${username}"/>
        <property name="password" value="${password}"/>
      </dataSource>
    </environment>
  </environments>
  <mappers>
    <mapper resource="org/mybatis/example/UserMapper.xml"/>
  </mappers>
</configuration>

4.jdbc.properties

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/mybatis?characterEncoding=utf8
jdbc.username=root
jdbc.password=ww2711554770

5.创建UserMapper.xml和UserMapper接口

<?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="org.flameking.mybatis.mapper.UserMapper">
    <!--int insertUser();-->
    <insert id="insertUser">
        insert into employee values(null,'张三',18,0)
    </insert>
</mapper>

public interface UserMapper {
  int insertUser();
}

6.测试文件

public class UserMapperTest {

  @Test
  public void insertUser() throws IOException {
    // Resource时MyBatis提供的外部配置文件加载类
    InputStream inputStream = Resources.getResourceAsStream("mybatis-config.xml");
    SqlSessionFactoryBuilder sqlSessionFactoryBuilder = new SqlSessionFactoryBuilder();
    SqlSessionFactory sqlSessionFactory = sqlSessionFactoryBuilder.build(inputStream);
    // SqlSession sqlSession = sqlSessionFactory.openSession(); 此时通过sqlSession对象操作的sql需要手动提交或回滚事务
    SqlSession sqlSession = sqlSessionFactory.openSession(true);
    // 创建动态代理的mapper对象
    UserMapper mapper = sqlSession.getMapper(UserMapper.class);
    int count = mapper.insertUser();
    System.out.println("count:"+count);
  }
}

MyBatis整合第三方数据源连接池

Spring整合MyBatis

SpringBoot整合MyBatis