Hi, In Tom White's Hadoop book, White discusses Writable collections and ends the section with the following:
For lists of a single type of Writable, ArrayWritable is adequate, but to store different types of Writable in a single list, you can use GenericWritable to wrap the elements in an ArrayWritable. Alternatively, you could write a general ListWritable using the ideas from MapWritable. I would like my mapper to emit a key that is a list of different WritableComparable types. In addition, the types of the WritableComparables is not known ahead of time. Has anyone done any work on this before? I've been basing my implementation off of MapWritable but I was hoping not to reinvent the wheel if possible. Thanks, Tim
