今天老师讲了mybatis的入门,作为入门基础没有将太多的mybatis的用法.而是通过一个实例,讲解了mybatis所实现的功能.这个实例就是定义了一个接口,用来执行所有的sql查询.在实现这个接口的过程中,用到了包括反射机制,generic等很多知识.

public interface SqlSession {

	// <T> T selectOne(String sql, Class<T> clazz, Object... params);
	<T> T selectOne(String sql, Class<T> clazz, Map<String, Object> params) throws SQLException;
	/*
	 * 1, (sql, params) => statement
	 * 
	 * 2, (clazz) => typehandler
	 * 3, typehandler.handler(rs)
	 * 4, return t
	 */

	<E> List<E> selectList(String sql, Class<E> clazz, Object... params) throws SQLException;
	
	int update(String sql, Object... params) throws SQLException;
}

	public <T> T selectOne(String sqlId, Class<T> clazz, Map<String, Object> params) {

		// 1. Open connection 			<= Connection pool

		// 2. Prepare statement 			<= PreparedStatement (maybe cached to reuse)

		// 3. Execute SQL with parameter	<= Database

		// 4. Get appropriate type handler  <= TypeHandler

		// 5. Handle result set				=> handle(result set, class type) => Object/List
		
		// 6. Release connection etc.
		
		// 7. Return result of step 5

		return null;
	}