small_demo

数据库设计

DROP TABLE IF EXISTS `user`;
CREATE TABLE `user` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `username` varchar(50) NOT NULL COMMENT '用户名',
  `password` varchar(32) NOT NULL COMMENT '密码，加密存储',
  `phone` varchar(20) DEFAULT NULL COMMENT '注册手机号',
  `email` varchar(50) DEFAULT NULL COMMENT '注册邮箱',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8 COMMENT='用户表';

实体类

public class User implements Serializable {

	private Long id;
	private String username;
	private String password;
	private String phone;
	private String email;

	public User() {
		super();
	}

	public User(Long id, String username, String password, String phone, String email) {
		super();
		this.id = id;
		this.username = username;
		this.password = password;
		this.phone = phone;
		this.email = email;
	}

	public Long getId() {
		return id;
	}

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

	public String getusername() {
		return username;
	}

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

	public String getPassword() {
		return password;
	}

	public void setPassword(String password) {
		this.password = password;
	}

	public String getPhone() {
		return phone;
	}

	public void setPhone(String phone) {
		this.phone = phone;
	}

	public String getEmail() {
		return email;
	}

	public void setEmail(String email) {
		this.email = email;
	}

	@Override
	public String toString() {
		return "User [id=" + id + ", username=" + username + ", password=" + password + ", phone=" + phone + ", email=" + email
				+ "]";
	}

}

UserMapper接口

public interface UserMapper {
	
	public User selectUserById(Long id);

}

mybatis-config.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">
  <!-- mybatis全局配置文件configuration: 配置数据源,配置连接池,映射文件 -->
<configuration>

 <!-- 引入外部资源文件 -->
 <properties resource="db.properties"/>
<!--  <plugins> -->
<!--   <plugin interceptor="com.github.abel533.mapperhelper.MapperInterceptor"> -->
<!--     <property name="IDENTITY" value="MYSQL"/> -->
<!--     <property name="mappers" value="com.github.abel533.mapper.Mapper"/> -->
<!--   </plugin> -->
<!-- </plugins> -->
  <!-- environments: 配置多个环境 default:默认使用的环境  -->
  <environments default="development">
  	<!-- environment : 配置单个环境  id : 当前环境的唯一标识-->
    <environment id="development">
      <!-- transactionManager:事务管理器   mybatis使用原生的jdbc管理事务 -->
      <transactionManager type="JDBC"/>
      <!-- dataSource:数据源 mybatis有哪些数据源? POOLED JNDI  UNPOOLED-->
      <dataSource type="POOLED">
        <property name="driver" value="${jdbc.driver}"/>
        <property name="url" value="${jdbc.url}"/>
        <property name="username" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
      </dataSource>
    </environment>
  </environments>
  <!-- mappers引入多个映射文件: 有四种引入 常用  mapper class  package 
       动态代理Dao开发模式可以使用: class package
  -->
  <mappers>
  	<!-- 引入映射资源文件  -->
    <mapper resource="UserMapper.xml"/>
    
<!--     <package name="com.huawei.support"/> -->
  </mappers>
</configuration>

db.properties

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/support-mybatis?useUnicode=true&characterEncoding=utf8&autoReconnect=true
jdbc.username=root
jdbc.password=******

lo4j.properties

log4j.rootLogger=DEBUG,A1
log4j.logger.com.atguigu = DEBUG
log4j.logger.org.mybatis = DEBUG

log4j.appender.A1=org.apache.log4j.ConsoleAppender
log4j.appender.A1.layout=org.apache.log4j.PatternLayout
log4j.appender.A1.layout.ConversionPattern=%-d{yyyy-MM-dd HH:mm:ss,SSS} [%t] [%c]-[%p] %m%n

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是映射文件配置 :统一定义sql语句标识的. namespace:可以随便定义唯一名称 但是使用mybatis的动态代理dao开发时,有规定特殊的意义(全类路径) -->
<mapper namespace="com.huawei.support.mapper.UserMapper">

	<!-- 根据用户id查询用户 -->
	<select id="selectUserById" parameterType="Long"
		resultType="com.huawei.support.entity.User">
		select * from User where id = #{id}
	</select>

</mapper>

测试类

public class UserMapperTest {
	SqlSessionFactory sqlSessionFactory;
	SqlSession sqlSession;
	UserMapper userMapper;

	@Before
	public void setUp() throws Exception {
		InputStream inputStream = Resources.getResourceAsStream("mybatis-config.xml");
		sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
		sqlSession = sqlSessionFactory.openSession(true);
		userMapper = sqlSession.getMapper(UserMapper.class);
	}

	@Test
	public void test() {
		User user = userMapper.selectUserById(2L);
		System.out.println(user);
	}

}