查增删改MySQL数据库固定模式

省略相关包的导入...
 
public class Base {
 
    public static Connection connection = null;
    public static PreparedStatement preparedStatement = null;
    public static ResultSet resultSet = null;
    public static int updateRows = 0;
 
    public Connection tomcatGetConnection() {
        try {
            Context context = new InitialContext();
            DataSource dataSource = (DataSource) context.lookup("java:comp/env/jdbc/mysql");
            connection = dataSource.getConnection();
        } catch (NamingException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return connection;
    }
 
    public ResultSet query(String sql, Object[] param) {
        try {
            preparedStatement = connection.prepareStatement(sql);
            for (int i = 0; i < param.length; i++) {
                preparedStatement.setObject(i + 1, param[i]);
            }
            resultSet = preparedStatement.executeQuery();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return resultSet;
    }
 
    public int update(String sql, Object[] param) {
        try {
            preparedStatement = connection.prepareStatement(sql);
            for (int i = 0; i < param.length; i++) {
                preparedStatement.setObject(i + 1, param[i]);
            }
            updateRows = preparedStatement.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return updateRows;
    }
 
    public void close() {
        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();
            }
        }
    }
 
}