serialization - GWT 能有效地序列化 java.lang.Longs 吗？

Question

我通过 GWT RPC 机制在客户端和服务器之间来回发送对象 ID。 id 以 Longs(8 字节)的形式从数据存储中出来。我认为我所有的 id 只需要 4 个字节，但可能会发生一些随机事件，给我一个 5 字节(或其他)的值。

GWT 是否会聪明地将这些值打包成某种可变长度编码，这样平均可以节省空间？我可以在某处指定它这样做吗？或者我应该编写自己的代码将多头复制到整数并注意那些特殊情况？

谢谢~

Answer 1

如 GWT documentation 中所述.

long: JavaScript has no 64-bit integral type, so long needs special consideration. Prior to GWT 1.5, the long type was was simply mapped to the integral range of a 64-bit JavaScript floating-point value, giving long variables an actual range less than the full 64 bits. As of GWT 1.5, long primitives are emulated as a pair of 32-bit integers, and work reliably over the entire 64-bit range. Overflow is emulated to match the expected behavior. There are a couple of caveats. Heavy use of long operations will have a performance impact due to the underlying emulation. Additionally, long primitives cannot be used in JSNI code because they are not a native JavaScript numeric type.

如果您的 id 可以放入整数，那么您可能会更好。否则，如果您使用的是 DTO，请将 id 设为 double ，这实际上存在于 Javascript 中。