数据库CRUD的通用方法

增删改的通用方法

/**     * 增删改的通用方法     *      * @param sql     * @param objects     * @return     */    public static int executeUpdate(String sql, Object... objects) {        int result = 0;        Connection conn = null;        PreparedStatement psmt = null;        try {            conn = getConnection();            psmt = conn.prepareStatement(sql);            if (objects != null) {                for (int i = 0; i < objects.length; i++) {                    psmt.setObject(i + 1, objects[i]); // 下标从1开始的                }            }            result = psmt.executeUpdate();        } catch (Exception e) {            e.printStackTrace();        } finally {            close(conn, psmt, null);        }        return result;    }

查询的通用方法

/**     * 查询的通用方法     *      * @param sql     * @param rsHandler     * @param objects     * @return     */    public static Object executeQuery(String sql, IResultSetUtil rsHandler,            Object... objects) {        Connection connection = null;        PreparedStatement preparedStatement = null;        ResultSet resultSet = null;        try {            connection = getConnection();            preparedStatement = connection.prepareStatement(sql);            if (objects != null) {                for (int i = 0; i < objects.length; i++) {                    preparedStatement.setObject(i + 1, objects[i]);                }            }            resultSet = preparedStatement.executeQuery();            return rsHandler.doHandler(resultSet);        } catch (Exception e) {            e.printStackTrace();        } finally {            close(connection, preparedStatement, resultSet);        }        return null;    }

查询单个字段值的通用方法

/**     * 查询单个字段值的通用方法     *      * @param sql     * @param objects     * @return     */    public static Object executeQuery(String sql, Object... objects) {        return executeQuery(sql, new IResultSetUtil() {            @Override            public Object doHandler(ResultSet rs) throws SQLException {                Object object = null;                if (rs.next()) {                    object = rs.getObject(1);                }                return object;            }        }, objects);    }