Serializing Dates with Protocol Buffers

Question

So after some searching, its been suggested to use an int64 epoch.

This is all well and great, but when interacting with my model, I would like to interact with actual LocalDate objects, so what are strategies for handling this?

The two strategies I can think of are:

• transform the deserialized model into ANOTHER different model. This is creating an extra object, I was hoping to avoid this.
• edit the generated models. I can't find any documentation on this so its probably quite risky

What is the common practice here?

Answer 1

I went with creating a generic solution for all dates/times:

message Timestamp {
    int64 seconds = 1;
    int32 nanos = 2;
}

With the following converters:

public static Timestamp fromLocalDate(LocalDate localDate) {
    Instant instant = localDate.atStartOfDay().toInstant(ZoneOffset.UTC);
    return Timestamp.newBuilder()
        .setSeconds(instant.getEpochSecond())
        .setNanos(instant.getNano())
        .build();
}

public static LocalDate toLocalDate(Timestamp timestamp) {
    return LocalDateTime.ofInstant(Instant.ofEpochSecond(timestamp.getSeconds(), timestamp.getNanos()), ZoneId.of("UTC"))
        .toLocalDate();
}