Mybatis工具類

public class MybatisUtil {

	static SqlSessionFactory sqlSessionFactory;

	static {		
		String resource = "mybatis-config.xml";
		InputStream inputStream;
		try {
			inputStream = Resources.getResourceAsStream(resource);
			sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}		
	}	
	/**
	 * 該方法呼叫必須在應用程式的成員方法中呼叫
	 * @return
	 */
	public static SqlSession findSqlSession(){
		
		return sqlSessionFactory.openSession();
	}
}

 

mapper.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="dao.UserMapper">
	

	<select id="selectAll" resultType="model.User">
		select * from USER
	</select>
	
	<!-- OGNL表示式 
		1.簡單型別引數,#{}中引數的命名可以自定義
		2.POJO引數，#{}中引數的命名必須是POJO對像中get方法的字尾（首字母小寫）一致。
	-->
	<select id="selectById" resultType="model.User">
		select * from USER where id = #{id}
	</select>
	
	<select id="selectByItem" resultType="model.User" parameterType="model.User">
		select * from USER where username=#{username} and password=#{password}
	</select>
	
	<insert id="insert" parameterType="model.User">
		insert into USER(username,password) values(#{username},#{password})
	</insert>
	
	<delete id="delete" parameterType="model.User">
		delete from USER where id = #{id}
	</delete>
	
	<update id="update" parameterType="model.User">
		update USER set username=#{username},password=#{password} where id = #{id}
	</update>
</mapper>
 

dao層程式碼

public class UserDao {

	public void insert(User user) {

		SqlSession session = MybatisUtil.findSqlSession();
		try {
			session.insert("dao.UserMapper.insert", user);
			// 提交事務
			session.commit();
		} catch (Exception e) {
			e.printStackTrace();
			session.rollback();
		} finally {
			session.close();
		}
	}

	public void delete(User user) {

		SqlSession session = MybatisUtil.findSqlSession();
		try {
			session.delete("dao.UserMapper.delete", user);
			// 提交事務
			session.commit();
		} catch (Exception e) {
			e.printStackTrace();
			session.rollback();
		} finally {
			session.close();
		}
	}

	public void update(User user) {
		SqlSession session = MybatisUtil.findSqlSession();
		try {
			session.update("dao.UserMapper.update", user);
			// 提交事務
			session.commit();
		} catch (Exception e) {
			e.printStackTrace();
			session.rollback();
		} finally {
			session.close();
		}
	}

	public User selectById(int id) {

		SqlSession session = MybatisUtil.findSqlSession();
		User user = null;
		try {
			user = session.selectOne("dao.UserMapper.selectById", id);
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			session.close();
		}
		return user;
	}

	public List<User> selectAll() {		
		SqlSession session = MybatisUtil.findSqlSession();
		List<User> users = null;
		try {
			users = session.selectList("dao.UserMapper.selectAll");
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			session.close();
		}
		return users;
	}

	public User selectByItem(User user) {
		SqlSession session = MybatisUtil.findSqlSession();
		try {
			user = session.selectOne("dao.UserMapper.selectByItem", user);
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			session.close();
		}
		return user;
	}
}
 

service層程式碼

public class UserService {

	UserDao dao = new UserDao();

	public void save(User user) {

		dao.insert(user);

	}

	public void remove(User user) {

		dao.delete(user);
	}

	public void modify(User user) {
		dao.update(user);
	}

	public User findById(int id) {
		return dao.selectById(id);
	}

	public List<User> findAll() {
		return dao.selectAll();
	}

	public User findByItem(User user) {

		return dao.selectByItem(user);
	}
}

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