java - MySQL 结果集 JsonWriter : jsonWriter. value((java.sql.Date) resultSet.getObject(column));

Question

我想用以下内容写入 MySQL 日期列值

jsonWriter.value((java.sql.Date) resultSet.getObject(column));

但是好像这是不可能的。它说long、Date、String都不适用于该类型。我怎样才能实现这个目标？

完整代码:

private static void writeField(final ResultSet resultSet, final JsonWriter jsonWriter, final ResultSetMetaData metaData, final int column) throws SQLException, IOException {
final int columnType = metaData.getColumnType(column);

switch ( columnType ) {
    case Types.BIT:
    case Types.TINYINT:
    case Types.SMALLINT:
        throw new UnsupportedOperationException("TODO: " + JDBCType.valueOf(columnType));
    case Types.INTEGER:
        jsonWriter.value((Integer) resultSet.getObject(column));
        break;
    case Types.BIGINT:
    case Types.FLOAT:
    case Types.REAL:
    case Types.DOUBLE:
    case Types.NUMERIC:
    case Types.DECIMAL:
    case Types.CHAR:
        throw new UnsupportedOperationException("TODO: " + JDBCType.valueOf(columnType));
    case Types.VARCHAR:
        jsonWriter.value((String) resultSet.getObject(column));
        break;
    case Types.LONGVARCHAR:
        jsonWriter.value((String) resultSet.getObject(column));
        break;
    case Types.DATE:
// here's the problem. i dont know to what to case the column.
        jsonWriter.value((java.sql.Date) resultSet.getObject(column));
        break;
    case Types.TIME:
    case Types.TIMESTAMP:
        jsonWriter.value((long) resultSet.getObject(column));
    case Types.BINARY:
    case Types.VARBINARY:
    case Types.LONGVARBINARY:
    case Types.NULL:
    case Types.OTHER:
    case Types.JAVA_OBJECT:
    case Types.DISTINCT:
    case Types.STRUCT:
    case Types.ARRAY:
    case Types.BLOB:
    case Types.CLOB:
    case Types.REF:
    case Types.DATALINK:
    case Types.BOOLEAN:
    case Types.ROWID:
    case Types.NCHAR:
    case Types.NVARCHAR:
    case Types.LONGNVARCHAR:
    case Types.NCLOB:
    case Types.SQLXML:
    case Types.REF_CURSOR:
    case Types.TIME_WITH_TIMEZONE:
    case Types.TIMESTAMP_WITH_TIMEZONE:
        throw new UnsupportedOperationException("TODO: " + JDBCType.valueOf(columnType));
    default:
        throw new UnsupportedOperationException("Unknown type: " + columnType);
    }
}

我还需要稍后实现时间戳 - 以防它们相关。

非常感谢! :)

Answer 1

好吧，我终于找到了如何做到这一点(我希望不是 100% 确定，因为我还无法在客户端上显示数据 - 但它可以编译并运行。这是代码:

    case Types.DATE:
        java.sql.Date sqlDate = (java.sql.Date) resultSet.getObject(column);
        LocalDate localDate = sqlDate.toLocalDate();
        DateTimeFormatter formatDt = DateTimeFormatter.ISO_LOCAL_DATE;
        String formattedDate = localDate.format(formatDt);
        jsonWriter.value((String) formattedDate);
        break;

我希望我没有以同样的方式格式化它两次？ :)

这里还有时间戳的代码:

case Types.TIMESTAMP:
    java.sql.Timestamp sqlTimeStamp = (java.sql.Timestamp) resultSet.getObject(column);
    LocalDateTime localDateTime = sqlTimeStamp.toLocalDateTime();
    DateTimeFormatter formatTimestamp = DateTimeFormatter.ISO_LOCAL_DATE;
    String formattedDateTime = localDateTime.format(formatTimestamp);
    jsonWriter.value((String) formattedDateTime);
    break;