Mybatis基础配置

mybatis文件配置及简单应用

1. 需求
   
   1. 根据用户id（主键）查询用户信息
   2. 模糊查询
   3. 添加、删除、更新用户
2. 环境
   
   1. mybatis
      
      1. 在GitHub上下载：https://github.com/mybatis/mybatis-3/releases

01_基础运行文件

实体类

package org.vector.entity;
public class User {
    private int cid;
    private String username;
    private String password;
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public int getCid() {
        return cid;
    }
    public void setCid(int cid) {
        this.cid = cid;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    @Override
    public String toString() {
        return "User [cid=" + cid + ", username=" + username + ", password="
                + password + "]";
    }
}

配置文件

全局配置文件

SqlMapConfig.xml

<?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>
  <environments default="development">
    <environment id="development">
      <transactionManager type="JDBC"/>
      <dataSource type="POOLED">
        <property name="driver" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://localhost:3306/test4"/>
        <property name="username" value="root"/>
        <property name="password" value="123"/>
      </dataSource>
    </environment>
  </environments>
  <mappers>
    <mapper resource="org/vector/entity/userMapper.xml"/>
  </mappers>
</configuration>

映射文件

UserMapper.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="org.vector.entity.UserMapper">
   <select id="selectUser" parameterType="int" resultType="org.vector.entity.User">
    select * from t_customer where cid = #{cid}
  </select>
</mapper>

测试类

// 根据id查询
public class Demo {
    @Test
    public void test() throws IOException {
        String resource = "SqlMapConfig.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession session = sqlSessionFactory.openSession();

        User user = session.selectOne("org.vector.entity.userMapper.selectUser", 1);
        System.out.println(user);
        session.close();
    }
}

第2个基础运行文件的源程序路径

02_基础运行文件

实体类

package org.vector.entity;
public class User {
    private int cid;
    private String username;
    private String password;
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public int getCid() {
        return cid;
    }
    public void setCid(int cid) {
        this.cid = cid;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    @Override
    public String toString() {
        return "User [cid=" + cid + ", username=" + username + ", password="
                + password + "]";
    }
}

配置文件

properties 文件

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/test4
username=root
password=123

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>
<properties resource="db.properties"/>
<typeAliases>
    <!-- 使用别名：
        映射文件中：
            namespace：直接使用映射文件名
            resultType：如果返回类型为实体类类型，直接写实体类名
        测试类中：
            对sql进行操作时，直接使用映射文件名.映射文件中的id名
    -->
    <package name="org.vector.entity"/>
</typeAliases>
  <environments default="development">
    <environment id="development">
      <transactionManager type="JDBC"/>
      <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/vector/entity/userMapper.xml"/>
  </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="userMapper">
  <select id="selectUser" parameterType="int" resultType="User">
    select * from t_customer where cid = #{cid}
  </select>
</mapper>

测试类

// 根据id查询
public class Demo {
    @Test
    public void test() throws IOException {
        String resource = "SqlMapConfig.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession session = sqlSessionFactory.openSession();

        User user = session.selectOne("userMapper.selectUser", 1);
        System.out.println(user);
        session.close();
    }
}