数据库JDBC DAO层方法

public class BaseDao {

	public static final String URL = "jdbc:mysql://localhost:3306/school?useunicode=true&characterEncoding=utf-8";
	public static final String USER = "root";
	public static final String PASSWORD = "1234";
	public static final String Driver = "com.mysql.jdbc.Driver";

	public static Connection getConnection() {

		Connection connection = null;

		try {
			// 1.加载驱动
			Class.forName(Driver);
			// 2建立连接
			connection = DriverManager.getConnection(URL, USER, PASSWORD);
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		} catch (SQLException e) {
			e.printStackTrace();
		}

		return connection;
	}

	public static int commonExecuteUpdate(String sql, Object[] params) {
		int row = 0;
		PreparedStatement preparedStatement = null;
		Connection connection = null;

		try {
			connection = getConnection();
			preparedStatement = connection.prepareStatement(sql);
			for (int i = 0; i < params.length; i++) {
				preparedStatement.setString(i + 1, params[i].toString());
			}
			row = preparedStatement.executeUpdate();
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			closeResources(preparedStatement, connection, null);
		}

		return row;
	}

	public static ResultSet commonExecuteQuery(String sql, Object[] params) {
		ResultSet resultSet = null;
		PreparedStatement preparedStatement = null;

		try {
			preparedStatement = getConnection().prepareStatement(sql);
			for (int i = 0; i < params.length; i++) {
				preparedStatement.setString(i + 1, params[i].toString());
			}
			resultSet = preparedStatement.executeQuery(sql);
		} catch (SQLException e) {
			e.printStackTrace();
		}

		return resultSet;
	}

	public static void closeResources(PreparedStatement preparedStatement, Connection connection, ResultSet resultSet) {
		if (resultSet != null) {
			try {
				resultSet.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}

		if (preparedStatement != null) {
			try {
				preparedStatement.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}

		if (connection != null) {
			try {
				connection.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
	}

}

以连接到本地school数据库为例