jdbc编程基础-1

我们给JdbcUtil增加一个结果解析的方法

    public static List<Map<String, Object>> convertToMap(ResultSet resultSet) {
        List<Map<String, Object>> list = new ArrayList<>();
        while(true) {
            try {
                if (!resultSet.next()) break;
            } catch (SQLException e) {
                e.printStackTrace();
            }
            Map<String, Object> map = new HashMap<>();

            ResultSetMetaData metaData = null;
            try {
                metaData = resultSet.getMetaData();
                int columnCount = metaData.getColumnCount();
                for(int i = 1; i <= columnCount; i ++) {
                    String columnName = metaData.getColumnName(i);
                    int columnType = metaData.getColumnType(i);
                    switch (columnType) {
                        case 4: map.put(columnName, resultSet.getInt(i)); break;
                        case 12: map.put(columnName, resultSet.getString(i)); break;
                        default:
                    }
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
            list.add(map);
        }
        return list;
    }