异常处理参考3层解耦

ublic class ScrollTest {

	public static void main(String[] args) throws SQLException {

		// TODO Auto-generated method stub

		Object[] params = new Object[]{"username","password"};

		read("select * from t_user where username=? and password=?",params);

	}

	// 可更新结果集

	public static void read(String sql,Object[] params) throws SQLException{

		Connection conn=null;

		PreparedStatement ps = null;

		ResultSet rs = null;

		try{

			conn = JdbcUtils.getConnection();

			ps=conn.prepareStatement(sql);

			ParameterMetaData pmd = ps.getParameterMetaData();

			int count = pmd.getParameterCount();

			for(int i=1;i<count;i++){

				ps.setObject(i, params[i-1]);

			}

			rs=ps.executeQuery();

			while (rs.next()) {

				System.out.print(rs.getObject(1)+" ");

				System.out.print(rs.getObject(2)+" ");

				System.out.print(rs.getObject(3)+" ");

				System.out.println();

			}

		}

		finally{

			JdbcUtils.free(rs, ps, conn);

		}

	}

}