Using java's serialization, almost every type in java language are serializable. but when you develop a big project, you will find you need another way to help you identity which type is serializable in MR context just by a glance. Then distinguished Writable interface may be a good way, although defining your own IntWritable is a little bit painful.
On 9/25/06, Curt Cox <[EMAIL PROTECTED]> wrote:
Hi, I'm curious why the new Writable interface was chosen rather than using Serializable. Handling version changes can be quite painful with standard serialization, but nothing seems to implement VersionedWritable. Introducing a new interface makes interoperation with other code more clumsy, since it means converting back and forth between standard and writable representations. Was it for speed? If so, I have implemented something similar to writable that has the advantage that no particular interface needs to be implemented. Consequently, the standard datatypes (java.lang.Integer etc...) can be used. The idea is that IO proxies register for each class. Whatever answers result from this thread, should be incorporated into the Javadoc. Thanks, Curt
