杰克逊 - 序列化日期对象

Question

我正在使用 Jackson 将 POJO 序列化为 JSON，但在格式化日期时遇到了困难。我在 Jackson 的网站上看到了这个 wiki：http://wiki.fasterxml.com/JacksonFAQDateHandling

通过这篇文章，我做了以下事情：

objectMapper.configure(SerializationConfig.Feature.WRITE_DATES_AS_TIMESTAMPS, false);

这会以 ISO-8601 格式打印 Date 对象，这正是我想要的。 “+0000”除外。根据 ISO-8601 格式，+hhmm 是与 UTC 的时间偏移量。杰克逊有没有办法禁用时间偏移？还是我只需要指定自定义日期格式？

Answer 1

我认为您最好的选择是在序列化时只传递新的日期格式。例如：

final ObjectMapper objectMapper = new ObjectMapper();
objectMapper.setDateFormat(new SimpleDateFormat("yyyy-MM-dd'T'HH:mm"));

基于JavaDocs on github，它提供了一些关于如何确定日期格式的见解，无需指定您自己的，我认为您只能使用数字时间戳或杰克逊定义的内置 ISO 格式。参考文档：

/**
     * Feature that determines whether Date (and date/time) values
     * (and Date-based things like {@link java.util.Calendar}s) are to be
     * serialized as numeric timestamps (true; the default),
     * or as something else (usually textual representation).
     * If textual representation is used, the actual format is
     * one returned by a call to
     * {@link com.fasterxml.jackson.databind.SerializationConfig#getDateFormat}:
     * the default setting being {@link com.fasterxml.jackson.databind.util.StdDateFormat},
     * which corresponds to format String of "yyyy-MM-dd'T'HH:mm:ss.SSSZ"
     * (see {@link java.text.DateFormat} for details of format Strings).
     *<p>
     * Note: whether this feature affects handling of other date-related
     * types depend on handlers of those types, although ideally they
     * should use this feature
     *<p>
     * Note: whether {@link java.util.Map} keys are serialized as Strings
     * or not is controlled using {@link #WRITE_DATE_KEYS_AS_TIMESTAMPS}.
     *<p>
     * Feature is enabled by default, so that date/time are by default
     * serialized as timestamps.
     */
    WRITE_DATES_AS_TIMESTAMPS(true),