Mybatis + Mybatis-Plus

纯Mybatis与Mybatis-Plus整合

测试数据

-- 创建测试表
CREATE TABLE `tb_user` (
`id` BIGINT ( 20 ) NOT NULL AUTO_INCREMENT COMMENT '主键ID',
`user_name` VARCHAR ( 20 ) NOT NULL COMMENT '用户名',
`password` VARCHAR ( 20 ) NOT NULL COMMENT '密码',
`name` VARCHAR ( 30 ) DEFAULT NULL COMMENT '姓名',
`age` INT ( 11 ) DEFAULT NULL COMMENT '年龄',
`email` VARCHAR ( 50 ) DEFAULT NULL COMMENT '邮箱',
PRIMARY KEY ( `id` ) 
) ENGINE = INNODB AUTO_INCREMENT = 1 DEFAULT CHARSET = utf8;

-- 插入测试数据
INSERT INTO `tb_user` ( `id`, `user_name`, `password`, `name`, `age`, `email` ) VALUES( '1', 'zhangsan', '123456', '张三', '18', '[email protected]' );
INSERT INTO `tb_user` ( `id`, `user_name`, `password`, `name`, `age`, `email` ) VALUES( '2', 'lisi', '123456', '李四', '20', '[email protected]' );
INSERT INTO `tb_user` ( `id`, `user_name`, `password`, `name`, `age`, `email` ) VALUES( '3', 'wangwu', '123456', '王五', '28', '[email protected]' );
INSERT INTO `tb_user` ( `id`, `user_name`, `password`, `name`, `age`, `email` ) VALUES( '4', 'zhaoliu', '123456', '赵六', '21', '[email protected]' );
INSERT INTO `tb_user` ( `id`, `user_name`, `password`, `name`, `age`, `email` ) VALUES( '5', 'sunqi', '123456', '孙七', '24', '[email protected]' );

pom.xml

	
		com.baomidou</groupId>
		mybatis-plus</artifactId>
		3.1.1</version>
	</dependency>
	
		mysql</groupId>
		mysql-connector-java</artifactId>
		5.1.47</version>
	</dependency>
	
		com.alibaba</groupId>
		druid</artifactId>
		1.0.11</version>
	</dependency>
	
		org.projectlombok</groupId>
		lombok</artifactId>
		true</optional>
		1.18.4</version>
	</dependency>
	
		junit</groupId>
		junit</artifactId>
		4.12</version>
	</dependency>
	
		org.slf4j</groupId>
		slf4j-log4j12</artifactId>
		1.6.4</version>
	</dependency>
</dependencies>

log4j.properties

log4j.rootLogger=DEBUG,A1

log4j.appender.A1=org.apache.log4j.ConsoleAppender
log4j.appender.A1.layout=org.apache.log4j.PatternLayout
log4j.appender.A1.layout.ConversionPattern=[%t] [%c]-[%p] %m%n

Mybatis实现查询User

第一步，编写mybatis-config.xml文件

"1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">

	"development">
		"development">
			type="JDBC" />
			type="POOLED">
				"driver" value="com.mysql.jdbc.Driver" />
				"url"
					value="jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=utf8&autoReconnect=true&allowMultiQueries=true&useSSL=false" />
				"username" value="root" />
				"password" value="123456" />
			</dataSource>
		</environment>
	</environments>
	
		"UserMapper.xml" />
	</mappers>
</configuration>

第二步，编写User实体对象

@Data
@NoArgsConstructor
@AllArgsConstructor
public class User {

	private Long id;
	private String userName;
	private String password;
	private String name;
	private Integer age;
	private String email;

}

第三步，编写UserMapper接口

public interface UserMapper {

	List<User> findAll();

}

第四步，编写UserMapper.xml文件

"1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
"cn.com.javakf.mapper.UserMapper">

	<select id="findAll" resultType="cn.com.javakf.pojo.User">
		select * from tb_user
	</select>

</mapper>

第五步，编写TestMybatis测试用例

public class TestMybatis {

	@Test
	public void testFindAll() throws Exception {

		String config = "mybatis-config.xml";
		InputStream inputStream = Resources.getResourceAsStream(config);
		SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);

		SqlSession sqlSession = sqlSessionFactory.openSession();
		UserMapper userMapper = sqlSession.getMapper(UserMapper.class);

		// 测试查询
		List<User> users = userMapper.findAll();
		for (User user : users) {
			System.out.println(user);
		}

	}

}

测试结果

[main] [cn.com.javakf.mapper.UserMapper.findAll]-[DEBUG] ==>  Preparing: select * from tb_user 
[main] [cn.com.javakf.mapper.UserMapper.findAll]-[DEBUG] ==> Parameters: 
[main] [cn.com.javakf.mapper.UserMapper.findAll]-[DEBUG] <==      Total: 5
User(id=1, userName=null, password=123456, name=张三, age=18, email=zhangsan@163.com)
User(id=2, userName=null, password=123456, name=李四, age=20, email=lisi@163.com)
User(id=3, userName=null, password=123456, name=王五, age=28, email=wangwu@163.com)
User(id=4, userName=null, password=123456, name=赵六, age=21, email=zhaoliu@163.com)
User(id=5, userName=null, password=123456, name=孙七, age=24, email=sunqi@163.com)

Mybatis+Mybatis-Plus实现查询User

第一步，将UserMapper继承BaseMapper，将拥有了BaseMapper中的所有方法

public interface UserMapper extends BaseMapper<User> {

	List<User> findAll();

}

第二步，使用Mybatis-Plus中的MybatisSqlSessionFactoryBuilder进行构建

public class TestMybatisPlus {

	@Test
	public void testFindAll() throws Exception {

		String config = "mybatis-config.xml";
		InputStream inputStream = Resources.getResourceAsStream(config);
		SqlSessionFactory sqlSessionFactory = new MybatisSqlSessionFactoryBuilder().build(inputStream);

		SqlSession sqlSession = sqlSessionFactory.openSession();
		UserMapper userMapper = sqlSession.getMapper(UserMapper.class);

		// 测试查询
		// List users = userMapper.findAll();
		List<User> users = userMapper.selectList(null);
		for (User user : users) {
			System.out.println(user);
		}

	}

}

运行报错
>
解决：在User对象中添加@TableName，指定数据库表名

@Data
@NoArgsConstructor
@AllArgsConstructor
@TableName("tb_user")
public class User {

	private Long id;
	private String userName;
	private String password;
	private String name;
	private Integer age;
	private String email;

}

测试结果

[main] [cn.com.javakf.mapper.UserMapper.selectList]-[DEBUG] ==>  Preparing: SELECT id,user_name,password,name,age,email FROM tb_user 
[main] [cn.com.javakf.mapper.UserMapper.selectList]-[DEBUG] ==> Parameters: 
[main] [cn.com.javakf.mapper.UserMapper.selectList]-[DEBUG] <==      Total: 5
User(id=1, userName=zhangsan, password=123456, name=张三, age=18, email=zhangsan@163.com)
User(id=2, userName=lisi, password=123456, name=李四, age=20, email=lisi@163.com)
User(id=3, userName=wangwu, password=123456, name=王五, age=28, email=wangwu@163.com)
User(id=4, userName=zhaoliu, password=123456, name=赵六, age=21, email=zhaoliu@163.com)
User(id=5, userName=sunqi, password=123456, name=孙七, age=24, email=sunqi@163.com)

简单说明
由于使用了MybatisSqlSessionFactoryBuilder进行了构建，继承的BaseMapper中的方法就载入到了SqlSession中，所以就可以直接使用相关的方法

代码托管：mybatis-mybatis-plus