Mybatis框架基础搭建及配置

Mybatis框架基础搭建及配置

目录

Mybatis框架基础搭建及配置

一、框架基础搭建

2、Mapper动态代理方式

---

一、框架基础搭建

 1、从官网上下Mybatis框架压缩包。新建一个Java工程，导入Mybatis中jar>mybatis-3.2.7\lib；本次项目采用Mysql数据库与junit测试，添加相应的jar依赖包；导入后将所有Jar添加值至项目>build path；创建相应的数据库表。

log4j.properties配置如下：

#定义LOG输出级别  
log4j.rootLogger=INFO,Console,File  
#定义日志输出目的地为控制台  
log4j.appender.Console=org.apache.log4j.ConsoleAppender  
log4j.appender.Console.Target=System.out  
#可以灵活地指定日志输出格式，下面一行是指定具体的格式  
log4j.appender.Console.layout = org.apache.log4j.PatternLayout  
log4j.appender.Console.layout.ConversionPattern=[%c] - %m%n  
  
#文件大小到达指定尺寸的时候产生一个新的文件  
log4j.appender.File = org.apache.log4j.RollingFileAppender  
#指定输出目录  
log4j.appender.File.File = C:/logs/ssm/ssm.log  
#定义文件最大大小  
log4j.appender.File.MaxFileSize = 10MB  
# 输出所以日志，如果换成DEBUG表示输出DEBUG以上级别日志  
log4j.appender.File.Threshold = ALL  
log4j.appender.File.layout = org.apache.log4j.PatternLayout  
log4j.appender.File.layout.ConversionPattern =[%p] [%d{yyyy-MM-dd HH\:mm\:ss}][%c]%m%n 

创建后的工程项目如下：

---

2、在classpath下创建SqlMapConfig.xml

3、在classpath下的config目录下创建sql映射文件Users.xml，并添加相应的增删该查方法：

    
	
		select * from user where id = #{id}
	
	
	
		select * from user where username like '%${value}%'
	
	
	
		INSERT INTO user (username,sex,birthday,address) VALUES(#{username},#{sex},#{birthday},#{address})
	
	
	
		delete from user where id=#{value}
	
	
	
		UPDATE user SET username=#{username},sex=#{sex},address=#{address} where id=#{id}
	

4、编写测试方法：

public class UserTest {

	@Test
	public void testFindUserById() throws Exception{
		String resource = "SqlMapConfig.xml";
		//通过流将核心配置文件读取进来
		InputStream inputStream = Resources.getResourceAsStream(resource);
		//通过核心配置文件输入流来创建会话工厂
		SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(inputStream);
		//通过工厂创建会话
		SqlSession openSession = factory.openSession();
		//第一个参数:所调用的sql语句= namespace+.+sql的ID
		User user = openSession.selectOne("test.findUserById", 1);
		System.out.println(user);
		openSession.close();
	}
	
	@Test
	public void testFindUserbyUserName() throws Exception{
		String resource = "SqlMapConfig.xml";
		InputStream inputStream = Resources.getResourceAsStream(resource);
		SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(inputStream);
		SqlSession openSession = factory.openSession();
		
		List list = openSession.selectList("test.findUserByUserName", "王");
		System.out.println(list);
	}
	
	@Test
	public void testInsertUser() throws Exception{
		String resource = "SqlMapConfig.xml";
		//通过流将核心配置文件读取进来
		InputStream inputStream = Resources.getResourceAsStream(resource);
		//通过核心配置文件输入流来创建会话工厂
		SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(inputStream);
		//通过工厂创建会话
		SqlSession openSession = factory.openSession();
		
		User user = new User();
		user.setUsername("赵四");
		user.setBirthday(new Date());
		user.setSex("1");
		user.setAddress("北京昌平");
		System.out.println("====" + user.getId());
		
		openSession.insert("test.insertUser", user);
		//提交事务(mybatis会自动开启事务,但是它不知道何时提交,所以需要手动提交事务)
		openSession.commit();
		
		System.out.println("====" + user.getId());
	}
	
	@Test
	public void testDelUserById()throws Exception{
		String resource = "SqlMapConfig.xml";
		//通过流将核心配置文件读取进来
		InputStream inputStream = Resources.getResourceAsStream(resource);
		//通过核心配置文件输入流来创建会话工厂
		SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(inputStream);
		//通过工厂创建会话
		SqlSession openSession = factory.openSession();
		
		openSession.delete("test.delUserById", 29);
		//提交
		openSession.commit();
	}
	
	@Test
	public void testUpdateUserById() throws Exception{
		String resource = "SqlMapConfig.xml";
		//通过流将核心配置文件读取进来
		InputStream inputStream = Resources.getResourceAsStream(resource);
		//通过核心配置文件输入流来创建会话工厂
		SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(inputStream);
		//通过工厂创建会话
		SqlSession openSession = factory.openSession();
		
		User user = new User();
		user.setId(28);
		user.setUsername("王麻子");
		openSession.update("test.updateUserById", user);
		
		//提交
		openSession.commit();
	}

---

---

 

2、Mapper动态代理方式

开发规范 

Mapper接口开发方法只需要程序员编写Mapper接口（相当于Dao接口），由Mybatis框架根据接口定义创建接口的动态代理对象，代理对象的方法体同上边Dao接口实现类方法。

Mapper接口开发需要遵循以下规范：

Mapper.xml文件中的namespace与mapper接口的类路径相同。

1. Mapper接口方法名和Mapper.xml中定义的每个statement的id相同
2. Mapper接口方法的输入参数类型和mapper.xml中定义的每个sql 的parameterType的类型相同
3. Mapper接口方法的输出参数类型和mapper.xml中定义的每个sql的resultType的类型相同

   ---

   Mapper.xml  映射文件

   
   
   
   
   	
   		select * from user where id = #{id}
   	
   
   	
   	   select * from user where username like '%${value}%' 
   	
   
   	
   	
   		select LAST_INSERT_ID() 
   	
   	  insert into user(username,birthday,sex,address) 
   	  values(#{username},#{birthday},#{sex},#{address})
   	
   
   
   

   接口文件

   Public interface UserMapper {
   	//根据用户id查询用户信息
   	public User findUserById(int id) throws Exception;
   	//查询用户列表
   	public List findUserByUsername(String username) throws Exception;
   	//添加用户信息
   	public void insertUser(User user)throws Exception; 
   }
   

   接口定义有如下特点：

 Mapper接口方法名和Mapper.xml中定义的statement的id相同。Mapper接口方法的输入参数类型和mapper.xml中定义的statement的parameterType的类型相同。Mapper接口方法的输出参数类型和mapper.xml中定义的statement的resultType的类型相同

测试 

Public class UserMapperTest extends TestCase {

	private SqlSessionFactory sqlSessionFactory;
	
	protected void setUp() throws Exception {
		//mybatis配置文件
		String resource = "sqlMapConfig.xml";
		InputStream inputStream = Resources.getResourceAsStream(resource);
		//使用SqlSessionFactoryBuilder创建sessionFactory
		sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
	}

	
	Public void testFindUserById() throws Exception {
		//获取session
		SqlSession session = sqlSessionFactory.openSession();
		//获取mapper接口的代理对象
		UserMapper userMapper = session.getMapper(UserMapper.class);
		//调用代理对象方法
		User user = userMapper.findUserById(1);
		System.out.println(user);
		//关闭session
		session.close();
		
	}
	@Test
	public void testFindUserByUsername() throws Exception {
		SqlSession sqlSession = sqlSessionFactory.openSession();
		UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
		List list = userMapper.findUserByUsername("张");
		System.out.println(list.size());

	}
Public void testInsertUser() throws Exception {
		//获取session
		SqlSession session = sqlSessionFactory.openSession();
		//获取mapper接口的代理对象
		UserMapper userMapper = session.getMapper(UserMapper.class);
		//要添加的数据
		User user = new User();
		user.setUsername("张三");
		user.setBirthday(new Date());
		user.setSex("1");
		user.setAddress("北京市");
		//通过mapper接口添加用户
		userMapper.insertUser(user);
		//提交
		session.commit();
		//关闭session
		session.close();
	}
	

}